![9
first.java
class first
{
public static void main (String arg[ ])
{
System.out.println(“Welcome to the world of Java”);
}
}
MS-DOS Prompt -Ÿ° õ‰¶M´ƒèœ. Ü Start--->Program--->Ms-Dos
Prompt â‹ è†ì¬÷¬òŠ ðò¡ð´ˆ¶ƒèœ.
ðì‹ðì‹ðì‹ðì‹ðì‹ 1.1
Þšõ£Á Þ™¬ôªòQ™ Windows -¡ Start Menu -M™ àœ÷ Run
è†ì¬÷¬ò AO‚ ªêŒ»ƒèœ. ܃°
ðì‹ðì‹ðì‹ðì‹ðì‹ 1.2](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-9-320.jpg)
![13
ܬñˆ¶ ܉î Loop Ýù¶ 1000 îì¬õ Þòƒ°ñ£Á ܬñˆ¶ ÜîÂœ
ïñ¶ ¹«ó£Aó£‹è¬÷ â¿F ªè£œ÷ «õ‡´‹.
Datatypes ñŸÁ‹ñŸÁ‹ñŸÁ‹ñŸÁ‹ñŸÁ‹ Variables
ïñ¶ Java ¹«ó£Aó£I™ ð™«õÁ ñFŠ¹è¬÷ ¬èò£œõ Variable-
è¬÷ à¼õ£‚°«õ£‹. Üšõ£Á Variable -è¬÷ à¼õ£‚°‹ªð£¿¶ ÜõŸP™
â‰î õ¬èò£ù ñFŠ¹è¬÷ð¢ ðFò «ð£A¡«ø£‹ â¡Á Ãø «õ‡´‹.
Üî¢î£¡ Datatype -èœ ðò¡ð´A¡øù.
C ªñ£NJ™ Þ¼Šð¶ «ð£¡«ø Java -M½‹ int, char, float ºîô£ù
Datatype -èœÞ¼è¢è¤ù¢øù. ÞõŸP™ ªõÁ‹ â‡è¬÷ ¬èò£œõ int
Data Type -ä ðò¡ð´ˆ¶A¡«ø£‹. â‡èO½‹ 123.456 ºîô£ù
ñFŠ¹è¬÷ð¢ ðFŠð float Data Type ðò¡ð´A¡ø¶. ⿈¶‚è¬÷
¬èò£œõ char Data Type ðò¡ð´A¡ø¶.
Þ‰î Data Type -è¬÷ îM˜ˆ¶ ð™«õÁ class -èœ Þ¼‚A¡øù.
ÜõŸ¬ø‚ ªè£‡´  Variable -è¬÷ à¼õ£‚A‚ ªè£œ÷ô£‹. H¡õ¼‹
¹«ó£Aó£I™ Cô Variable -è¬÷ à¼õ£‚A ÜõŸP™ âšõ£Á ñFŠ¹è¬÷
ðF‰¶ ¬õŠð¶ â¡ðî¬ù è£íô£‹.
Listing 1.2
class pro1_2
{
public static void main(String arg[])
{
int rollno, tamil, english, maths, science, social, total;
String sname;
float avg;
rollno=1;
sname=”Reena”;
tamil=65;
english=80;
maths=50;
science=90;
social=75;](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-13-320.jpg)
![14
total=tamil+english+maths+science+social;
avg=total/5;
System.out.println(“Roll Number : “ + rollno);
System.out.println(“Student Name : “ + sname);
System.out.println(“Tamil : “ + tamil);
System.out.println(“English : “ + english);
System.out.println(“Maths : “ + maths);
System.out.println(“Science : “ + science);
System.out.println(“Social : “ + social);
System.out.println(“Total : “ + total);
System.out.println(“Average : “ + avg);
}
}
Þ‰î ¹«ó£Aó£I™  rollno, tamil, english, maths, science, social, total
ºîLò Variable -è¬÷ int data type -™ à¼õ£‚AJ¼‚A¡«ø£‹. sname â¡Â‹
Variable -ä String â¡Â‹ Class -ù¢ Object Ýè à¼õ£‚AJ¼‚A¡«ø£‹. Þ‰î
String Class -ä ðò¡ð´ˆ¶õî¡ Íô‹ ªî£ì˜ ⿈¶‚è¬÷ (String °è÷¢)
¬èò£÷ô£‹. avg â¡Â‹ Variable Ýù¶ float data type -™ Þ¼‚A¡ø¶.
à¼õ£‚èŠð†ì Variable -èœ Ü¬ùˆF½‹ ÜõŸPŸ‚°Pò ñFŠ¹èœ
ðFòŠð†®¼‚A¡øù. ÜõŸP™ àœ÷ ñFŠ¹èœ Screen -™ Display
ªêŒõîŸè£è System.out.println â¡Â‹ Function àð«ò£A‚èŠð†®¼‚A¡ø¶.
cƒèœ ÞŠªð£¿¶ Ièˆ ªîOõ£è Cô Ü®Šð¬ì Java Programing
º¬øè¬÷ ªîK‰¶ ªè£œ÷ «õ‡´‹. â‰î Java ¹«ó£Aó£I½‹ å¼ class
â¿îŠð†®¼‚°‹. Þ‰î ¹«ó£Aó£I™ class student â¡Á
ªè£´‚èŠð†®¼Šð¬îè¢ èõQ»ƒèœ. class -è¬÷Š ðŸP  ªîOõ£è
H¡õ¼‹ â´ˆ¶è£†´èO½‹, ܈Fò£òƒèO½‹, è£íô£‹.
ªñ£î¢îî¢î¤ô¢ å¼ Java ¹«ó£Aó£ñ£ù¶ å¼ class-¡ àœ Üì颰è¤ù¢ø¶.
Þï¢î class -ù¢ à÷¢ public static void main(String arg[]) â¡ø function
â¿îŠð†®¼Šð¬î èõQ»ƒèœ. Þ‰î function Þ¼ŠH¡  å¼ Java
Application å¡P¬ù ⿶A¡«ø£‹ â¡Á ªð£¼œ. ¬ìò Java
¹«ó£Aó£‹ Þòƒ°‹«ð£¶ main function -™ Þ¼‰¶  Þòé¢è Ýó‹H‚°‹.](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-14-320.jpg)
![15
H¡õ¼‹ Syntax -ä èõQ»ƒèœ. ÞF™ Þ¼Šð¶ «ð£™  cƒèœ Java
Application -è¬÷ â¿î «õ‡´‹ â¡ðî¬ù G¬ùM™ ªè£œÀé¢è÷¢.
class <Class Name>
{
public static void main(String arg[ ])
{
...
}
}
«ñø¢è¢èí¢ì ¹«ó£è¤ó£ñ¤¬ù 覫ö ªè£´è¢èð¢ð좴÷¢÷¶ «ð£ô¢ èñ¢¬ðô¢
ªêò¢¶ Þòè¢è¤ð¢ ð£¼é¢è÷¢.
ðì‹ðì‹ðì‹ðì‹ðì‹ 1.4
Operators
¹«ó£è¤ó£ñ¢è¬÷ ⿶õîø¢° Operator -è÷¤ù¢ ðé¢è÷¤ð¢¹
ñ¤è¾ñ¢ Þù¢ø¤ò¬ñò£î¶ Ýè¤ù¢ø¶. Arithmetic Operators,
Relational Operators, Logical
Operators âù ðô õ¬èè÷£è Operator -è÷¢
Þ¼è¢è¤ù¢øù. +, -, *, / ºîô£ù¬õ Arithmetic Operator](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-15-320.jpg)
![16
-è÷¢ Ý°ñ¢. Þõø¢¬øè¢ ªè£í¢´ Calculation -è¬÷ê¢ ªêò¢¶ ªè£÷¢÷ô£ñ¢.
<, >, <=, >=, ! =, = = ºîô£ù¬õ Relational Operator -è÷¢ Ý°ñ¢.
Þõø¢ø¤ô¢ <, > âù¢ð¶ º¬ø«ò Less than ñø¢Áñ¢ Greater than âù¢ðî¬ùè¢
°ø¤è¢è¤ù¢ø¶. <=, >= Ýè¤ò¬õ º¬ø«ò Less than or equal to ñø¢Áñ¢ greater
than or equal to Ýè¤òõø¢¬øè¢ °ø¤è¢è¤ù¢ø¶. ! = âù¢ð¶ not equal to âù¢ðî¬ùè¢
°ø¤è¢è¤ù¢ø¶. == âù¢ð¶ equal to âù¢ðî¬ùè¢ °ø¤è¢è¤ù¢ø¶. Þï¢î Relational
Operator -è¬÷è¢ ªè£í¢´ Þóí¢´ âù¢è÷¤ô¢ ⶠªðó¤ò¶, ê¤ó¤ò¶, Üô¢ô¶
êññ£è Þ¼è¢è¤ù¢øî£ Üô¢ô¶ Þô¢¬ôò£ «ð£ù¢ø îèõô¢è¬÷ Condition -
è÷¤ô¢ à÷¢ ðòù¢ð´î¢î¤ Üø¤ï¢¶ ªè£÷¢÷ô£ñ¢.
&&, ||, ! ºîô£ù¬õè÷¢ Logical Operator -è÷¢ Ý°ñ¢. æù¢Á袰ñ¢
«ñø¢ðì¢ì èí¢®ûù¢è¬÷ê¢ êó¤ð£ó¢ð¢ðîø¢° Þï¢î Logical Operator -è¬÷ð¢
ðòù¢ð´î¢¶ è¤ù¢«ø£ñ¢. && âù¢ð¶ Logical AND Ý°ñ¢. Þóí¢´ Condition -
è÷¢ Þ¼è¢è¤ù¢ø Þìî¢î¤ô¢ Þóí¢´«ñ èì¢ì£òñ£è Ìó¢î¢î¤ ªêò¢òð¢ðì «õí¢´ñ¢
âù¢ø 郎ôò¤ô¢ Þï¢î && (AND Operator) 郎ùð¢ ðòù¢ð´î¢î¤è¢ ªè£÷¢÷ô£ñ¢.
ñ£ø£è Þóí¢´ Condition -è÷¢ Þ¼è¢è¤ù¢ø Þìî¢î¤ô¢ ãî£õ¶ åù¢Á
Ìó¢î¢î¤ò£ù£ô¢ «ð£¶ñ¢ âù¢øõ£Á Þ¼ï¢î£ô¢ Üîø¢° || (OR Operator)
ðòù¢ð´è¤ù¢ø¶. ! âù¢ð¶ not Operator Ý°ñ¢.
if Condition
ï£ñ¢ ãø¢è¢ªèù«õ Condition -âù¢ø£ô¢ âù¢ù âù¢ðî¬ùð¢ ðø¢ø¤
Üø¤ï¢î¤¼è¢è¤ù¢«ø£ñ¢. 覫ö ªè£´è¢èð¢ð좴÷¢÷ Syntax -¬ùð¢ ðòù¢ð´î¢î¤
if Condition -è¬÷ àð«ò£èð¢ð´î¢î¤è¢ ªè£÷¢÷ô£ñ¢.
if (bodean Expression)
{
......
}
[else
{
......
}]
Listing 1.3
class pro1_3
{](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-16-320.jpg)
![17
public static void main(String argv[])
{
int x;
int y;
x=30;
y=50;
if (x > y)
{
System.out.println(“X is greater than Y”);
}
else
if (x < y)
{
System.out.println(“Y is greater than X”);
}
else
{
System.out.println(“Both Are Same”);
}
}
}
Þï¢î ¹«ó£è¤ó£ñ¤ô¢ x ñø¢Áñ¢ y âù¢Á Þóí¢´ int data type variable -è÷¢
à¼õ£è¢èð¢ð좴 Üõø¢ø¤ô¢ ê¤ô ñî¤ð¢¹è¬÷ ðî¤ï¢¶ Þ¼è¢è¤ù¢«ø£ñ¢.
Þ颰 if Condition -ù¤¬ùð¢ ðòù¢ð´î¢î¤ x -ô¢ à÷¢÷ ñî¤ð¢¹ ªðó¤òî£
Üô¢ô¶ Y -ô¢ à÷¢÷ ñî¤ð¢¹ ªðó¤òî£ âù¢Á èí¢´ ð¤®è¢°ñ¢ ªð£¼ì¢´
¹«ó£è¤ó£ñ¢ â¿î¤ò¤¼è¢è¤ù¢«ø£ñ¢. ºîô¤ô¢ if condition -ù¤ô¢ x Ýù¶ y -ò¤¬ù
õ¤ì ªðó¤òî£ âù¢ðî¬ùê¢ êó¤ ð£ó¢è¢è¤ù¢«ø£ñ¢. Üõ¢õ£Á Þ¼ð¢ð¤ù¢ Üï¢î
condition -ù¤ù¢ à÷¢«÷ à÷¢÷ ð°î¤ò£ù¶ Þò颰è¤ù¢ø¶. Üîø¢° 覫ö
ªè£´è¢èð¢ð좴÷¢÷ else ð°î¤è÷¢ «õ¬ô ªêò¢ò£¶.
æ¼ «õ¬ô ºîô¤ô¢ ªè£´è¢èð¢ðì¢ì condition ªð£¼ï¢îõ¤ô¢¬ô âù¤ô¢
else ð°î¤ î£ù£è Þò颰è¤ù¢ø¶. Þ颰 else -ù¤ô¢ ñø¢Áªñ£Á if condition
Þ¼è¢è¤ù¢ø¶. Üî¤ô¢ y Ýù¶ x -¬ù õ¤ì ªðó¤òî£ âù¢ðî¬ù check
Java-3](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-17-320.jpg)
![18
ªêò¢õîø¢°ø¤ò condition ªè£´è¢èð¢ð좮¼è¤ù¢ø¶. Þ¶ ªð£¼ï¢î¤ò¤¼ð¢ð¤ù¢
Üî¤ô¢ ªè£´è¢èð¢ðì¢ì èì¢ì¬÷è÷¢ Þò颰ñ¢. Þô¢¬ôªòù¤ô¢ 覫ö à÷¢÷
else ð°î¤ò£ù¶ Þò颰è¤ù¢ø¶.
°ø¤ð¢¹:°ø¤ð¢¹:°ø¤ð¢¹:°ø¤ð¢¹:°ø¤ð¢¹:
if condition -è÷¤ô¢ else Ýù¶ èì¢ì£òñ¢ ðòù¢ð´î¢î «õí¢´ñ¢ âù¢ð¶
Þô¢¬ô. if «õ¬ô ªêò¢òõ¤ô¢¬ô âù¤ô¢ else ð°î¤ Þ¼ð¢ð¤ù¢ ܶ
î£ù£è «õ¬ôªêò¢»ñ¢.
Listing 1.4
class pro1_4
{
public static void main(String arg[])
{
int rollno, tamil, english, maths, science, social, total;
String sname;
float avg;
rollno=1;
sname=”Reena”;
tamil=65;
english=80;
maths=50;
science=90;
social=75;
total=tamil+english+maths+science+social;
avg=total/5;
System.out.println(“Roll Number : “ + rollno);
System.out.println(“Student Name : “ + sname);
System.out.println(“Tamil : “ + tamil);
System.out.println(“English : “ + english);
System.out.println(“Maths : “ + maths);
System.out.println(“Science : “ + science);
System.out.println(“Social : “ + social);
System.out.println(“Total : “ + total);
System.out.println(“Average : “ + avg);](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-18-320.jpg)
![20
{
public static void main(String arg[])
{
int x;
for (x=1; x<=100; x++)
{
System.out.println(x);
}
}
}
Þï¢î ¹«ó£è¤ó£ñ¤ô¢ ï£ñ¢ 1 -ô¤¼ï¢¶ 100 õ¬ó âù¢è¬÷ Display
ªêò¢õîø¢°ø¤ò for loop -¬ù Þòø¢ø¤ò¤¼è¢è¤ù¢«ø£ñ¢. Þ颰 ºîô¤ô¢ x âù¢Âñ¢
variable -ô¢ 1 âù¢ø ñî¤ð¢ð¤¬ù intialize ªêò¢è¤ù¢«ø£ñ¢. ܴ condition -ù¤ô¢
x<=100 âù¢Á ªè£´î¢î¤¼è¢è¤ù¢«ø£ñ¢. Þîù¢ð® x -ô¢ 100 Üô¢ô¶ Üîø¢°
°¬øõ£ù ñî¤ð¢¹è÷¢ õ¬ó Þ¼è¢èô£ñ¢. 100 -袰 «ñø¢ð¢ðì¢ì ñî¤ð¢¹è÷¢
õ¼ñ¢ªð£¿¶ loop -¬ù õ¤ì¢´ ªõ÷¤«ò õ õ¤ì «õí¢´ñ¢ âù¢Á ªð£¼÷¢.
increment ð°î¤ò¤ô¢ x++ âù¢Á ªè£´è¢èð¢ð¢ì®¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þîù¢ð®
x -ô¢ îø¢ªð£¿¶ ޼袰ñ ñî¤ð¢«ð£´ 1 âù¢ø ðî¤ð¢ð¤¬ù Ãì¢®è¢ ªè£÷¢÷
«õí¢´ñ¢ âù¢Á ªð£¼÷¢. loop Ýù¶ åõ¢ªõ£Á º¬ø»ñ¢ condition-ù¤¬ù
êó¤ð£ó¢î¢¶ õ¤ì¢´ ÜîÂ÷¢ ªè£´è¢èð¢ð좮¼è¢°ñ¢ èì¢ì¬ùè¬÷ Þò袰è¤ù¢ø¶.
ð¤ù¢ùó¢ condition ð°î¤ Þò颰è¤ù¢ø¶. Þ¶ «ð£ù¢Á ñ¦í¢´ñ¢ ñ¦í¢´ñ¢ loop -ù¢
à÷¢ Þ¼è¢è¤ù¢ø îèõô¢è÷¢ Þò颰è¤ù¢øù.
while loop
while loop Ýù¶ ªõ¼ñ¢ condition -ù¤¬ù ñ좴«ñ ªè£í¢´÷¢÷¶. for
loop -ä «ð£ô intialization ñø¢Áñ¢ increment ð°î¤è÷¢ Þ颰 èì¢ì¬÷ò¤Â÷¢
Þô¢¬ô. Ýù£ô¢ ï£ñ¢ Üõø¢¬ø èì¢ì£òñ£è «õÁ Þìé¢è÷¤ô¢ ðòù¢ð´î¢î
«õí¢´ñ¢.
while (condition)
{
statements...
}
Listing 1.6
class pro1_6](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-20-320.jpg)
![21
{
public static void main(String arg[])
{
int x;
x=1;
while (x!=100)
{
System.out.println(x);
x++;
}
}
}
Þ颰 x âù¢ø variable à¼õ£è¢èð¢ð좮¼è¢è¤ù¢ø¶. while loop
Ýóñ¢ð¤ð¢ðîø¢° ºù¢«ù x=1; âù¢Á intialize ªêò¢òð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢.
while loop -ù¢ à÷¢ x!=100 âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¬î»ñ¢ èõù¤»é¢è÷¢.
Þîù¢ð® x -ô¢ 100 -¬ù îõ¤ø «õÁ âï¢î ñî¤ð¢¹è÷¢ Þ¼ï¢î£½ñ¢ loop -ù¢ à÷¢
ªêô¢ôô£ñ¢ âù¢Á ªð£¼÷¢. x++ âù¢ø increment statement loop -ù¢ à÷¢
Þ¼ð¢ðî¬ùè¢ èõù¤»é¢è÷¢.
do while loop
Þ¶¾ñ¢ while loop -¬ù𢠫ð£ô«õ Þò颰è¤ù¢ø¶. Ýù£ô¢ while loop
Ýù¶ ºîô¤ô¢ condition -ù¤¬ù check ªêò¢¶õ¤ì¢´ ð¤ù¢ èì¢ì¬÷è¬÷
Þò袰è¤ù¢ø¶. Ýù£ô¢ do while loop Ýù¶ ºîô¤ô¢ èì¢ì¬÷è¬÷
Þòè¢è¤õ¤ì¢´ ð¤ù¢ùó¢ condition -ù¤¬ù check ªêò¢»ñ¢.
do
{
Statement....
}while(condition);
Listing 1.7
class pro1_7
{
public static void main(String arg[])
{](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-21-320.jpg)
![25
public static void main(String arg[])
{
book java = new book();
book oracle = new book();
java.store(“Java Language”,”Packianathan”,
”AnuRagham”,250);
oracle.store(“Oracle Datbase”,”Packianathan”,
”AnuRagham”,125);
java.display();
oracle.display();
}
}
Þï¢î𢠹«ó£è¤ó£ñ¤ô¢ Book âù¢ªø£¼ class â¿îð¢ð좮¼ð¢ð¬îè¢
èõù¤»é¢è÷¢. Þ颰 main( ) Function ù¤¬ùî¢ îõ¤ó¢î¢¶ Üîø¢° ºù¢ ðô õó¤è÷¢
Þ¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Üõø¢ø¤ô¢ ºîô¤ô¢ BookName, AuthorName, Publisher,
Price Ýè¤ò variable -è÷¢ à¼õ£è¢èð¢ð좮¼è¢è¤ù¢øù. ܬõ Þï¢îè¢ class-ù¢
data member -è÷¢. Üî¬ùî¢ ªî£ìó¢ï¢¶ Store ñø¢Áñ¢ display âù¢Á Þóí¢´
function -è÷¢ Þ¼è¢è¤ù¢øù. Þ¬õ Methods âù¢Á ܬöè¢èð¢ð´è¤ù¢øù.
Þõø¢ø¤ô¢ store function Ýù¶ parameter -è÷¤ù¢ õö¤ò£è ñî¤ð¢¹è¬÷𢠪ðø¢Á
Üõø¢¬ø data member -è÷¤ô¢ ðî¤ï¢¶ ¬õð¢ðîø¢°ð¢ ðòù¢ð´è¤ù¢ø¶. ܶ«ð£ô¢
display function Ýù¶ data member -è÷¤ô¢ à÷¢÷ ñî¤ð¢¹è¬÷ Display ªêò¢¶ð¢
ð£ó¢ð¢¢ðîø¢°ð¢ ðòù¢ð´è¤ù¢ø¶.
Þï¢î𢠹«ó£è¤ó£ñ¤¬ù Compile ªêò¢¶ Þò袰ñ¢ªð£¿¶ main( ) function
ù¤ô¢ ޼ î£ù¢ ¹«ó£è¤ó£ñ¢ Þòé¢è Ýóñ¢ð¤è¢°ñ¢. ÞîÂ÷¢
Book java = new Book ( ) ;
Book oracle = new Book ( ) ;
âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þ¶«õ å¼ class -ô¤¼ï¢¶
Object-´è¬÷ à¼õ£è¢°ñ¢ º¬ø. ºîô¤ô¢ class -ù¢ ªðòó¤¬ùê¢ Ãø¤, ð¤ù¢ùó¢
à¼õ£è¢°è¤ù¢ø Object -®ù¢ ªðòó¤¬ùê¢ ªê£ô¢ô «õí¢´ñ¢. Þ颰 java ñø¢Áñ¢
oracle âù¢ðù Book Class -ô¤¼ï¢¶ à¼õ£è¢èð¢ð´ñ¢ Object -´è÷¢ Ý°ñ¢.
ܴ ï£ñ¢ = âÂñ¢ assignment operator -ø¤¬ùè¢ ªè£´î¢¶ Üî¬ùî¢ ªî£ì
Java-4](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-25-320.jpg)
![27
{
empno=tempno;
ename=tename;
job=tjob;
salary=tsalary;
}
public void view()
{
System.out.println(“Employee Number : “ + empno);
System.out.println(“Employee Name : “ + ename);
System.out.println(“Job : “ + job);
System.out.println(“Salary : “ + salary);
}
}
class tata
{
public static void main(String arg[])
{
emp nancy = new emp();
emp john = new emp();
nancy.assign(101,”Nancy Jenifer”,”Analyst”,6000);
john.assign(102,”John Thomas”,”Programmer”,6000);
nancy.view();
john.view();
}
}
Þï¢î𢠹«ó£è¤ó£ñ¤ô¢ emp âù¢ø class åù¢Áñ¢ Tata âù¢ø class åù¢Áñ¢
â¿îð¢ð좮¼è¢è¤ù¢øù. Þï¢î Þóí¢´ class -ø¢è¢°ñ¢ Þ¬ìò¤ô¢ âï¢îªõ£¼
ªî£ìó¢¹ñ¢ Þô¢¬ô.
emp âÂñ¢ class -ô¢ å¼ èñ¢ªðù¤ò¤ô¢ «õ¬ôð¢ ð£ó¢è¢è¤ù¢ø ªî£ö¤ô£÷ó¢
è÷¤ù¢ îèõô¢è¬÷è¢ ¬èò£÷¢õîø¢°ø¤ò ¹«ó£è¤ó£ñ¤¬ù â¿î¤ò¤¼è¢è¤ù¢«ø£ñ¢.](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-27-320.jpg)
![28
Üî£õ¶ Þî¤ô¢ empno, ename, job, salary âù¢ø îèõô¢è¬÷ê¢ «êèó¤è¢°ñ¢
ªð£¼ì¢´ variable -è¬÷ à¼õ£è¢è¤, Üõø¢ø¤ô¢ ñî¤ð¢¹è¬÷ ðî¤õîø¢°ñ¢, ñø¢Áñ¢
Üõø¢ø¤ô¢ Þ¼è¢è¤ù¢ø ñî¤ð¢¹è¬÷ è£í¢ðîø¢è¢°ñ£è º¬ø«ò assign ñø¢Áñ¢
view Ýè¤ò function -è¬÷ â¿î¤ò¤¼è¢è¤ù¢«ø£ñ¢.
Tata âù¢ªø£¼ class Þ¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þ¶ Tata âù¢Âñ¢
èñ¢ªðù¤ò¤ù¢ îèõô¢è¬÷ ðó£ñó¤è¢°ñ¢ class âù¢Á èø¢ð¬ù ªêò¢¶
ªè£÷¢Àé¢è÷¢. Þï¢î Class -ô¢ î£ù¢ main function Ýù¶ Þ¼è¢è¤ù¢ø¶
âù¢ðî¬ù»ñ¢ èõù¤»é¢è÷¢. Þï¢î ¹«óè¤ó£ññ¤¬ù ï¦é¢è÷¢ Compile ªêò¢¶
Run ªêò¢»ñ¢ ªð£¿¶ Tata èñ¢ªðù¤ò¤ô¢ à÷¢÷ main function î£ù¢ Þò颰ñ¢
âù¢ð¶ àé¢èÀ袰 郎ùõ¤¼è¢°ñ¢. Þï¢î main function -ô¢ ï£ñ¢ emp âù¢Âñ¢
class õ¤¬ùê¢ ê£ó¢ï¢î Þóí¢´ object -´è¬÷ à¼õ£è¢è¤ò¤¼è¢è¤ù¢«ø£ñ¢.
Üî£õ¶,
emp nancy = new emp( ) ;
emp john = new emp( ) ;
ºîô¤ò õó¤è¬÷ °ø¤ð¢ð¤´è¤ù¢«ø£ñ¢. ï£ñ¢ Þ¼ð¢ð«î£ Tata âù¢Âñ¢ Class-
ø¢è°÷¢ Üé¢è¤¼ï¢¶ «õªø£¼ class -Ýù emp -ò¤ù¢ Object -´è¬÷ Þ颰
à¼õ£è¢è¤è¢ ªè£÷¢Àè¤ù¢«ø£ñ¢. ð¤ù¢ùó¢ nancy ñø¢Áñ¢ john Ýè¤ò Object-
´èÀ袰ø¤ò assign ñø¢Áñ¢ view function -è¬÷ð¢ ðòù¢ð´î¢î¤è¢
ªè£÷¢Àè¤ù¢«ø£ñ¢.
Þõø¢ø¤ô¤¼ï¢¶ å¼ class â¿îð¢ð좴õ¤ì¢ì£ô¢ Üîù¢ Object -´è¬÷
«õÁ âï¢î class -ù¢ à÷¢ ޼ñ¢ ðòù¢ð´î¢î¤è¢ ªè£÷¢÷ô£ñ¢ âù¢ðî¬ù
ªî÷¤õ£è Üø¤ï¢¶ ªè£÷¢Àé¢è÷¢. Þð¢ªð£¿¶, class âù¢ø£ô¢ âù¢ù âù¢Á
åó÷¾ ªî÷¤ï¢î¤¼ð¢ð¦ó¢è÷¢. Þù¤ class ù¤¬ùð¢ ðø¢ø¤ò ªî÷¤õ£ù Syntax -ä
ð£ó¢ð¢«ð£ñ¢.
Syntex:
[modifiers] class <class name> [extend <superclass>] [implements
<interfaces>]
âð¢ªð£¿¶«ñ èì¢ì¬÷è÷¤ù¢ Syntax -è¬÷ ð®è¢°ñ¢ ªð£¿¶ [ ] brackets-
è÷¤ù¢ à÷¢ Þ¼ð¢ð¬õ Option -è÷¢ Ý°ñ¢. Üî£õ¶ Üõø¢¬øð¢ ðòù¢ð´î¢îô£ñ¢
Üô¢ô¶ ðòù¢ð´î¢î£ñ½ñ¢ Þ¼è¢èô£ñ¢. Þ¶õ¬ó ï£ñ¢ ð£ó¢î¢î â´î¢¶è¢
è£ì¢´è÷¤ô¢ [modifiers], [extend super class] ñø¢Áñ¢ [implement interface] ºîô£ù
Þùé¢è÷¢ ðòù¢ð´î¢îð¢ðìõ¤ô¢¬ô. ܬõ åõ¢ªõ£ù¢Áñ¢ ªõõ¢«õÁ](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-28-320.jpg)
![30
System.out.println(“”);
}
}
class child extends father
{
String cname;
int cage;
public void store(String tcname, int tcage)
{
cname=tcname;
cage=tcage;
}
public void display()
{
System.out.println(“Child’s Name : “ + cname);
System.out.println(“Child’s Age : “ + cage);
System.out.println(“”);
}
}
class school
{
public static void main(String arg[])
{
child allen = new child();
allen.assign(“Sebastian Raj”,30);
allen.store(“Allen Smith”,3);
allen.view();
allen.display();
}
}](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-30-320.jpg)
![32
Constructors
å¼ class -ù¢ à÷¢ Üï¢î class -ù¢ ªðòó¤«ô«ò function -è÷¤¬ù ⿶ñ¢
º¬ø«ò consturctor âù¢Á ܬöè¢èð¢ð´è¤ù¢ø¶.
â´î¢¶è¢è£ì¢ì£è class circle âù¢Á å¼ class Þ¼ð¢ðî£è ªè£í¢ì£ô¢ Üï¢î
class -ù¢ à÷¢ circle( ) âù¢ø ªðòó¤ô¢ å¼ function ޼袰ñ£ù£ô¢ ܶ
Constructor function âù¢Á ܬöè¢èð¢ð´è¤ù¢ø¶.
ê£î£óíñ£è ï£ñ¢ å¼ class -ù¢ à÷¢ ⿶ñ¢ function -è¬÷ Üï¢î class-
ù¢ Object -è÷¤ù¢ õö¤ò£èî¢î£ù¢ Þò袰«õ£ñ¢. Ýù£ô¢ Constructor function
è÷¤¬ù𢠪ð£¼î¢î õ¬óò¤ô¢ ï£ñ£è Üî¬ù Þòè¢èî¬õò¤ô¢¬ô. ñ£ø£è
ܶ î£ù£è«õ Þò颰ñ¢. âõ¢õ£ªøù¤ô¢ âð¢ªð£¿ªîô¢ô£ñ¢ å¼ class - ù¢
Object à¼õ£è¢èð¢ð´è¤ù¢ø«î£, Üð¢ªð£¿ªîô¢ô£ñ¢ Üï¢î Class ù¢ à÷¢
Constructor Function -è÷¢ ޼袰ñ¢ ðì¢êî¢î¤ô¢ ܬõ î£ù£è ºîô¤ô¢
Þòé¢è¤õ¤´ñ¢.
âù«õ Þï¢î Constructor º¬øò¤ù¢ Íôñ¢ class -ù¢ Object ´è÷¢
à¼õ£°ñ¢ êñòî¢î¤ô¢ ïìè¢è «õí¢®ò intialization ºîô¤ò ïñè¢°î¢ «î¬õò£ù
«õ¬ôèÀ袰ø¤ò ¹«ó£è¤ó£ñ¢è¬÷ â¿î¤è¢ ªè£÷¢÷ô£ñ¢.
Listing 2.4
class hello
{
hello()
{
System.out.println(“Hello Constructor”);
}
public static void main(String arg[])
{
hello one = new hello();
hello two = new hello();
hello three = new hello();
}
}
Þï¢î ¹«ó£è¤ó£ñ¤ô¢ hello âù¢ø class â¿îð¢ð좮¼è¢è¤ù¢ø¶. «ñ½ñ¢ hello
âù¢ø class-ù¢ ªðòó¤«ô«ò function åù¢Áñ¢ â¿îð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢.](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-32-320.jpg)
![34
public void store(int tx,int ty,int tradius)
{
x=tx;
y=ty;
radius=tradius;
}
public void display()
{
System.out.println(“X value: “ + x);
System.out.println(“Y value: “ + y);
System.out.println(“Radius: “ + radius);
System.out.println(“”);
}
}
class check
{
public static void main(String arg[])
{
circle one = new circle();
circle two = new circle(5,10,15);
circle three = new circle(two);
one.display();
two.display();
three.display();
}
}
Þï¢î ¹«ó£è¤ó£ñ¤ô¢ circle âù¢Á å¼ class â¿îð¢ð좮¼è¢è¤ù¢ø¶.
ê£î£óíñ£è å¼ circle õ¬óò «õí¢´ñ¢ âù¢ø£ô¢ ¬ñòð¢¹÷¢÷¤»ñ¢(Centre
Point) Ýóºñ¢(Radius) «î¬õ. âù«õ ï£ñ¢ x, y ñø¢Áñ¢ radius âù¢Á Íù¢Á
variable -è¬÷ class-ù¢ à÷¢ â¿î¤ò¤¼è¢è¤ù¢«ø£ñ¢. circle âù¢ø ªðòó¤ô¢ Íù¢Á
Constructor function -è÷¢ â¿îð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. ºîô¢ circle
constructor function -ù¤ô¢ âï¢î å¼ ñî¤ð¢¹èÀñ¢ argument -è÷£è](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-34-320.jpg)
![37
«õÁ ðô ¹«ó£è¤ó£ñ¢è÷¤ô¢ Þ¼ï¢¶è¢ ðòù¢ð´î¢î¤è¢ ªè£÷¢÷ô£ñ¢.
â´î¢¶è¢è£ì¢ì£è ï£ñ¢ Java õ¤ô¢ ðòù¢ð´î¢¶ñ¢ String âù¢Âñ¢ class -¬ù
public class Ýè â¿î¤ Þ¼ð¢ðîù£ô¢ î£ù¢ ïñ¢ñ£ô¢ Üî¬ù ܬù
¹«ó£è¤ó£ñ¢è÷¤½ñ¢ ðòù¢ð´î¢î º®è¤ù¢ø¶.
this ñø¢Áñ¢ñø¢Áñ¢ñø¢Áñ¢ñø¢Áñ¢ñø¢Áñ¢ super
Java õ¤ô¢ this ñø¢Áñ¢ super âù Þóí¢´ ê¤ø𢹠keyword -è÷¢ Þ¼è¢è¤ù¢øù.
å¼ class -ù¢ à÷¢ ï£ñ¢ ðô¢«õÁ variable -è÷¢ ñø¢Áñ¢ function -è¬÷ â¿î¤
ò¤¼ð¢«ð£ñ¢. Þõø¢¬ø Üï¢î class -è÷¤ù¢ Object ´è÷¢ õö¤ò£è Þò袰è¤ù¢«ø£ñ¢
Üô¢ôõ£? Üï¢î êñòé¢è÷¤ô¢ åõ¢ªõ£Á Object -ø¢è¢°ñ¢ âù¢Á îù¤î¢îù¤ò£è
variable -è÷¢ ºîô£ù¬õ à¼õ£°ñ¢. âï¢î variable âï¢î object -®Â¬ìò¶
âù¢ðî¬ù ªê£ô¢õîø¢è¢è£è this âÂñ¢ operator ðòù¢ð´è¤ù¢ø¶.
Listing 2.6
class student
{
int rollno;
String name;
public void store(int rollno, String name)
{
this.rollno = rollno;
this.name = name;
}
public void display()
{
System.out.println(“Roll Number: “ + this.rollno);
System.out.println(“Name: “ + this.name);
System.out.println(“”);
}
public static void main(String arg[])
{
student nancy = new student();](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-37-320.jpg)
![40
{
System.out.println(“City Name : “ + city_name);
}
}
class country
{
public static void main(String arg[])
{
city chennai = new city(“Chennai”);
chennai.state_display();
chennai.city_display();
}
}
Þï¢î𢠹«ó£è¤ó£ñ¤ô¢ state ñø¢Áñ¢ city âù¢Á Þóí¢´ class -è÷¢ Þ¼è¢è¤ù¢øù.
Þóí¢´ñ¢ inheritance º¬øò¤ô¢ Þ¬íè¢èð¢ð좮¼è¢è¤ù¢ø¶. state âù¢ð¶ superclass
Ýè¾ñ¢city âù¢ð¶childclassÝè¾ñ¢ Þ¼è¢è¤ù¢ø¶. Þóí¢´ class è÷¤½«ñ constructor
function â¿îð¢ð좮¼è¢è¤ù¢ø¶. main() function-ù¤ô¢ ï£ñ¢ citychennai=newcity(‘chennai’)
âù¢Á ªè£´î¢¶ chennai âù¢Á å¼ Object -¬ù city âÂñ¢ class -ô¢ ޼
à¼õ£è¢°è¤ù¢«ø£ñ¢. ï£ñ¢ parameter Ýè ªè£´è¢°ñ¢ ‘Chennai’ âù¢ø ñî¤ð¢¹ cityclass-ù¢
constructor -¼è¢° àó¤ò¶. city class -ù¢ constructor function -ù¤ô¢ ï£ñ¢ super (‘Tamil nadu’);
âù¢Á ªè£´î¢î¤¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þï¢î èì¢ì¬÷ super classÝù state ¬ìò
constructor function -ø¢° ñî¤ð¢¹è¬÷è¢ ªè£´è¢è¤ù¢ø¶.
Package
Package âù¢ð¶ ðô java ¹«ó£è¤ó£ñ¢è¬÷»ñ¢ ñø¢Áñ¢ class -è¬÷»ñ¢ ªè£í¢ì å¼
ªî£°ð¢¹ Ý°ñ¢. Üî£õ¶ å¼ º¬ø â¿îð¢ðì¢ì ¹«ó£è¤ó£ñ ¢è¬÷«ò£ Üô¢ô¶ class
-è¬÷«ò£ «õí¢®ò ªð£¿¶ «î¬õð¢ðì¢ì Þìé¢è÷¤ô¢ ñ¦í¢´ñ¢ ñ¦í¢´ñ¢ ðòù¢ð´î¢î¤è¢
ªè£÷¢õîø¢è¢è£è Package º¬øð¢ ðòù¢ð´è¤ù¢ø¶. ï£ñ¢ ⿶è¤ù¢ø ðô¢«õÁ class -
è¬÷ å¼ Package Ýè à¼õ£è¢è¤õ¤ì¢´ ð¤ù¢ùó¢ Üî¬ù «õí¢®ò Þìî¢î¤ô¢
ðòù¢ð´î¢î¤è¢ ªè£÷¢÷ô£ñ¢.
Ü«î«ð£ô¢ java ªñ£ö¤ò¤½ñ¢ ðô¢«õÁ ðí¤è¬÷ê¢ ªêò¢õîø¢è¢è£è
Ëø¢Áè¢èíè¢è£ù class -èÀñ¢ ¹«ó£è¤ó£ñ¢èÀñ¢ ðô Package -è÷£è â¿îð¢ð좴
Þ¼è¢è¤ù¢øù. åõ¢ªõ£Á Package -ñ¢ °ø¤ð¢ð¤ì¢ì ê¤ô ðòù¢ð£´è¬÷ ªè£í¢ì
class -è¬÷ îù¢ùèî¢«î ªè£í¢´÷¢÷¶. Þõø¢¬ø ï£ñ¢ «õí¢®ò êñòé¢è÷¤ô¢](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-40-320.jpg)
![66
ðòù¢ð´î¢î¤ Þ¶õ¬ó applet -è¬÷ âõ¢õ£Á à¼õ£è¢°õ¶ âù¢Á ð£ó¢î¢î¤¼è¢
è¤ù¢«ø£ñ¢. Þ«î awt Package -ô¢ à÷¢÷ Component-è¬÷ ªè£í¢´ Windows
Operating System -î¢î¤ô¢ «õ¬ô ªêò¢»ñ¢ Application-è¬÷»ñ¢ à¼õ£è¢è º®»ñ¢.
Visual Basic ºîô£ù GUI Package è¬÷ à¼õ£è¢°õ¶ «ð£ù¢«ø ܬù
õ¬èò£ù Application -è¬÷»ñ¢ Java-õ¤ô¢ à¼õ£è¢è Þò½ñ¢.
ªð£¶õ£è windows -ô¢ å¼ Application Þòé¢è «õí¢´ñ¢ âù¢ø£ô¢ Üï¢î
Application -ø¢° âù¢Á å¼ window frame Þ¼è¢è «õí¢´ñ¢ Üô¢ôõ£? Üî£õ¶
TitleBar, Minimize Button, Maximize Button, Close Box Ýè¤òõø¢¬ø ªè£í¢ì Frame
åù¢Á Üõñê¤òñ¢. Üî¢î¬èò Frame åù¢ø¤¬ù à¼õ£è¢è¤ Üî¤ô¢ ïñ¢º¬ìò
Component-è¬÷ «ð£ì¢´î¢ ªè£÷¢÷ô£ñ¢.
°ø¤ð¢ð£è Application åù¢ø¤¬ù â¿î «õí¢´ñ¢ âù¢ø£ô¢ main( ) function-
ô¢ î£ù¢ ¹«ó£è¤ó£ñ¤¬ù â¿î «õí¢´ñ¢ âù¢ðî¬ù âð¢ªð£¿¶ñ¢ 郎ùõ¤ô¢
ªè£÷¢Àé¢è÷¢.
Listing 3.7
import java.awt.*;
import java.awt.event.*;
public class appl
{
public static void main(String a[])
{
Frame baskar=new Frame(“Application”);
baskar.resize(300,300);
baskar.show();
}
}
Þï¢î ¹«ó£è¤ó£ñ¤ô¢ ï£ñ¢ main ( ) function ù¤¬ù ðòù¢ð´î¢î¤ò¤¼ð¢ð¬îè¢
èõù¤»é¢è÷¢. âù«õ Þ¶ å¼ Application Ý°ñ¢. Þî¤ô¢
Frame xyz = new Frame(‘Application’);
âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þï¢î class-ù¢ Íôñ¢ ïñ袰
å¼ Window frame 褬ìè¢è¤ù¢ø¶. constructors-ô¢ ªè£´è¢°ñ¢ String Ýù¶
window õ¤ù¢ Title Ýè õ¼è¤ù¢ø¶. Þï¢î window õ£ù¶ âï¢î ï¦÷ñ¢ ñø¢Áñ¢](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-66-320.jpg)
![69
my_frm.resize(250,100);
my_frm.show();
}
static void main(String argv[])
{
my_app hello=new my_app();
}
}
Þï¢î𢠹«ó£è¤ó£ñ¤ô¢ my_frm âù¢ªø£¼ frame à¼õ£è¢èð¢ð좮¼è¢è¤ù¢ø¶.
lname, lpass âù¢Á Þóí¢´ Label Object-èÀñ¢ ñø¢Áñ¢ tname, tpass âù¢Á Þóí¢´
TextField object-èÀñ¢ à¼õ£è¢èð¢ð좴÷¢÷ù. Þï¢î Object-è÷¢ Þï¢î Frame
ù¤ô¢ õ¼õîø¢è¢è£è ¹«ó£è¤ó£ñ¢ â¿îð¢ð좴÷¢÷¶. my_app( ) âù¢Á å¼ Con-
structor function â¿îð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. ÞîÂ÷¢ ï£ñ¢ ܬù
initialize «õ¬ôè¬÷»ñ¢ ªêò¢î¤¼è¢è¤ù¢«ø£ñ¢. main ( ) function ù¤ô¢
my_app hello = new my_app( );
âù¢Á ïñ¢º¬ìò class -ø¢° å¼ Object à¼õ£è¢èð¢ð´õ¬îè¢ èõù¤»é¢è÷¢.
Þï¢î Object à¼õ£°ñ¢ ªð£¿¶ Üï¢î Object -ô¢ à÷¢÷ Class-ù¢ ܬù
Variable èÀñ¢ à¼õ£è¢èð¢ð좴 Constructor Function -Âñ¢ î£ù£è Þòé¢è](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-69-320.jpg)
![71
Menu Program
Listing 3.9
import java.awt.*;
import java.awt.event.*;
public class menu
{
public static void main(String a[])
{
Frame my_frm=new Frame(“Menu Programme”);
MenuBar bar = new MenuBar();
Menu File = new Menu(“File”);
Menu Edit = new Menu(“Edit”);
// MenuItem abc=new MenuItem(“New...”);
// File.add(abc);
File.add(new MenuItem(“New”));
File.add(new MenuItem(“Open”));
File.add(new MenuItem(“Save”));
File.add(new MenuItem(“Save As”));
File.add(new MenuItem(“-”));
File.add(new MenuItem(“PageSetup”));
File.add(new MenuItem(“Print”));
File.add(new MenuItem(“-”));
File.add(new MenuItem(“Exit”));
Edit.add(new MenuItem(“Undo”));
Edit.add(new MenuItem(“-”));
Edit.add(new MenuItem(“Cut”));
Edit.add(new MenuItem(“Copy”));
Edit.add(new MenuItem(“Paste”));
bar.add(File);
bar.add(Edit);
my_frm.setMenuBar(bar);
my_frm.resize(300,300);
my_frm.show();](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-71-320.jpg)
![81
import WidgetPanel;
import Shape;
public class JavaDraw extends Applet
{
boolean m_fStandAlone=false;
private WidgetPanel guiPanel=null;
private int oldX=0,oldY=0;
private Image theImage=null;
private String imagePath=”tiger1.jpg”;
private String m_foregroundColor=null;
private String m_backgroundColor=null;
private final String PARAM_forecolor=”forecolor”;
private final String PARAM_backcolor=”backcolor”;
String GetParameter(String strName,String args[])
{
if(args==null)
{
return getParameter(strName);
}
int i;
String strArg=strName + “=”;
String strValue=null;
for(i=0;i<args.length;i++)
{
if(strArg.equalsIgnoreCase
(args[i].substring(0,strArg.length())))
{
strValue=args[i].substring(strArg.length());
if(strValue.startsWith(“””))
{
strValue=strValue.substring(1);
if(strValue.endsWith(“””))
strValue=strValue.substring
Java-11](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-81-320.jpg)
![82
(0,strValue.length()-1);
}
}
}
return strValue;
}
void GetParameter(String args[])
{
String param;
param=GetParameter(PARAM_forecolor,args);
if(param!=null)
m_foregroundColor=param;
param=GetParameter(PARAM_backcolor,args);
if(param!=null)
m_backgroundColor=param;
}
public static void main(String args[])
{
JavaDrawFrame frame=new
JavaDrawFrame(“JavaDraw!”);
frame.show();
frame.setVisible(false);
frame.setSize(frame.getInsets().left+
frame.getInsets().right+400,frame.getInsets().top+
frame.getInsets().bottom+350);
JavaDraw applet_JavaDraw=new JavaDraw();
frame.add(“Center”,applet_JavaDraw);
applet_JavaDraw.m_fStandAlone=true;
applet_JavaDraw.GetParameter(args);
applet_JavaDraw.init();
frame.show();
}](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-82-320.jpg)
![83
public JavaDraw()
{
}
public String getAppletInfo()
{
return “Name:JavaDrawrn”+
“Author: Packia Nathanrn”;
}
public String[][]getParameterInfo()
{
String[][]info=
{
{ PARAM_forecolor,”String”,”Specifies default fore-
ground color of this program(must be color class variable)”},
{ PARAM_backcolor,”String”,”Specifies default
background color of this program(must be a color class variable)”},
};
return info;
}
public void init()
{
if(!m_fStandAlone)
GetParameter(null);
resize(400,350);
this.setLayout(new BorderLayout());
setBackground(Color.white);
guiPanel=new WidgetPanel();
add(“North”,guiPanel);
addMouseListener(getMouseListener());
addMouseMotionListener(getMouseMotionListener());
}
MouseListener getMouseListener()](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-83-320.jpg)
![85
{
if(threeD)
g.fill3DRect(oldX,oldY,x,y,true);
else
g.fillRect(oldX,oldY,x,y);
}else{
if (threeD)
g.draw3DRect
(oldX+1,oldY+1,x+1,y+1,true);
else
g.drawRect(oldX,oldY,x,y);
}
break;
case Shape.OVAL:
if(fill)
{
g.fillOval(oldX,oldY,x,y);
}else{
g.drawOval(oldX,oldY,x,y);
}
break;
case Shape.ARC:
if (fill)
{
g.fillArc(oldX,oldY,100,100,x,y);
}else{
g.drawArc(oldX,oldY,100,100,x,y);
}
break;
case Shape.POLY:
int xCoords[]=
{x+oldX,x+55,x+65,x+80,x+80,x+oldX};
int yCoords[]=
{y+oldY,y+38,y+55,y+30,y+75,y+oldY};
Polygon thePoly=new](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-85-320.jpg)
![97
ðì‹ðì‹ðì‹ðì‹ðì‹ 5.1
Listing 5.2
import javax.swing.*;
import java.awt.*;
public class swg2
{
public static void main(String argv[])
{
JFrame abc=new JFrame(“Hello”);
JLabel lbl_name=new JLabel(“Name: “);
JTextField txt_name=new JTextField();
JLabel lbl_age=new JLabel(“Age: “);
JTextField txt_age=new JTextField();
GridLayout xyz=new GridLayout(2,2);
abc.getContentPane().setLayout(xyz);
abc.getContentPane().add(lbl_name);
abc.getContentPane().add(txt_name);
abc.getContentPane().add(lbl_age);
abc.getContentPane().add(txt_age);](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-97-320.jpg)
![99
Listing 5.3
import javax.swing.*;
import java.awt.*;
public class swg3
{
public static void main(String arg[])
{
JFrame abc=new JFrame(“Hello”);
Icon i_one=new ImageIcon(“bullet1.gif”);
Icon i_two=new ImageIcon(“bullet2.gif”);
Icon i_three=new ImageIcon(“bullet3.gif”);
Icon i_four=new ImageIcon(“bullet4.gif”);
JButton but_one=new JButton(“One”,i_one);
JButton but_two=new JButton(“Two”,i_two);
JComboBox com_one=new JComboBox();
com_one.addItem(“Tamil Nadu”);
com_one.addItem(“Andra Pradesh”);
com_one.addItem(“Karnataka”);
com_one.addItem(“Maharastra”);
com_one.addItem(“Orisa”);
JComboBox com_two=new JComboBox();
com_two.addItem(“India”);
com_two.addItem(“Pakistan”);
ButtonGroup sex=new ButtonGroup();
JRadioButton male=new JRadioButton(“Male”,i_three);
JRadioButton female=new JRadioButton(“Female”,i_four);
sex.add(male);
sex.add(female);](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-99-320.jpg)
![101
ðì‹ðì‹ðì‹ðì‹ðì‹ 5.3
Listing 5.4
import javax.swing.*;
import java.awt.*;
public class toolbar extends JFrame
{
public static void main(String argv[])
{
toolbar abc = new toolbar();
JMenuBar mymen = new JMenuBar();
JMenu file = new JMenu(“File”);
JMenu edit = new JMenu(“Edit”);
file.add(new JMenuItem(“New”));
file.add(new JMenuItem(“Open”));
file.add(new JMenuItem(“Close”));
edit.add(new JMenuItem(“Cut”));](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-101-320.jpg)
![104
{
Icon one = new ImageIcon (“bullet1.gif”);
Icon two = new ImageIcon (“bullet2.gif”);
Icon three = new ImageIcon (“bullet3.gif”);
JTabbedPane country = new JTabbedPane();
country.addTab(“India”,one,new india());
country.addTab(“Pakistan”,two,new pakistan());
country.addTab(“China”,three,new china());
d.add(country);
}
public static void main(String argv[])
{
tabbed xyz = new tabbed();
xyz.setTitle(“Tabbed Demo”);
xyz.resize(400,400);
xyz.show();
}
}
class india extends JPanel
{
JLabel lbl_pre = new JLabel (“President : Mr. K.R.
Narayanan”);
JLabel lbl_pri = new JLabel (“Prime Minister : Mr. A.B.
Vajpayee”);
JLabel lbl_chi = new JLabel (“Chief Minister : Mr. M.
Karunanidhi”);
india()
{
setLayout(new FlowLayout(FlowLayout.LEFT,10,10));
add(lbl_pre);
add(lbl_pri);
add(lbl_chi);](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-104-320.jpg)
![109
JTree countrymaram = new JTree(country);
x.add(countrymaram);
}
public static void main(String argv[])
{
maram abc = new maram();
abc.setTitle(“Tree View Example”);
abc.resize(400,400);
abc.show();
}
}
Þï¢î ¹«ó£è¤ó£ñ¤ô¢ Treeview âù¢ø¬öè¢èð¢ð´ñ¢ Component-è÷¢ õ¤÷è¢èð¢
ð좴÷¢÷ù. Treeview âù¢ð¶ å¼ Item î¢î¤ø¢°÷¢ ñø¢ªø£Á Item âù¢Á
åù¢øù¢ð¤ù¢ åù¢ø£è à÷¢«÷ ªêô¢½ñ¢ð® ޼袰ñ¢ ܬñ𢹠ݰñ¢.
ðì‹ðì‹ðì‹ðì‹ðì‹ 5.6](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-109-320.jpg)
![111
System.exit(0);
}
}
);
// Take the dummy data from SwingSet.
final String[] names = {“First Name”, “Last Name”, “Favorite
Color”,“Favorite Number”, “Vegetarian”};
final Object[][] data = {
{“Mark”, “Andrews”, “Red”, new Integer(2), new Boolean(true)},
{“Tom”, “Ball”, “Blue”, new Integer(99), new Boolean(false)},
{“Alan”, “Chung”, “Green”, new Integer(838), new
Boolean(false)},
{“Jeff”, “Dinkins”, “Turquois”, new Integer(8), new
Boolean(true)},
{“Amy”, “Fowler”, “Yellow”, new Integer(3), new
Boolean(false)},
{“Brian”, “Gerhold”, “Green”, new Integer(0), new
Boolean(false)},
{“James”, “Gosling”, “Pink”, new Integer(21), new
Boolean(false)},
{“David”, “Karlton”, “Red”, new Integer(1), new Boolean(false)},
{“Dave”, “Kloba”, “Yellow”, new Integer(14), new
Boolean(false)},
{“Peter”, “Korn”, “Purple”, new Integer(12), new
Boolean(false)},
{“Phil”, “Milne”, “Purple”, new Integer(3), new Boolean(false)},
{“Dave”, “Moore”, “Green”, new Integer(88), new
Boolean(false)},
{“Hans”, “Muller”, “Maroon”, new Integer(5), new
Boolean(false)},
{“Rick”, “Levenson”, “Blue”, new Integer(2), new
Boolean(false)},
{“Tim”, “Prinzing”, “Blue”, new Integer(22), new
Boolean(false)},
{“Chester”, “Rose”, “Black”, new Integer(0), new](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-111-320.jpg)
![112
Boolean(false)},
{“Ray”, “Ryan”, “Gray”, new Integer(77), new Boolean(false)},
{“Georges”, “Saab”, “Red”, new Integer(4), new
Boolean(false)},
{“Willie”, “Walker”, “Phthalo Blue”, new Integer(4), new
Boolean(false)},
{“Kathy”, “Walrath”, “Blue”, new Integer(8), new
Boolean(false)},
{“Arnaud”, “Weber”, “Green”, new Integer(44), new
Boolean(false)}
};
// Create a model of the data.
TableModel dataModel = new AbstractTableModel()
{
// These methods always need to be implemented.
public int getColumnCount() { return names.length; }
public int getRowCount() { return data.length;}
public Object getValueAt(int row, int col) {return
data[row][col];
}
// The default implementations of these methods in
// AbstractTableModel would work, but we can refine them.
public String getColumnName(int column) {return
names[column];}
public Class getColumnClass(int col) {return
getValueAt(0,col).getClass();}
public boolean isCellEditable(int row, int col) {return (col==4);}
public void setValueAt(Object aValue, int row, int column)
{
data[row][column] = aValue;
}](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-112-320.jpg)
![113
};
// Instead of making the table display the data as it would nor-
mally with:
// JTable tableView = new JTable(dataModel);
// Add a sorter, by using the following three lines instead of the
one above.
JTable tableView = new JTable(dataModel);
JScrollPane scrollpane = new JScrollPane(tableView);
scrollpane.setPreferredSize(new Dimension(700, 300));
frame.getContentPane().add(scrollpane);
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args)
{
new Table();
}
}
Þï¢î ¹«ó£è¤ó£ñ¤ô¢ table âù¢ø¬öè¢èð¢ð´ñ¢ Component õ¤÷è¢èð¢
ð좴÷¢÷¶. table -è÷¤ô¢ ïñ¢ñ£ô¢ Record-è¬÷ display ªêò¢¶ ªè£÷¢÷
º®»ñ£îô£ô¢ Þîù¢ ðòù¢ð£´ Þù¢ø¤ò¬ñò£îî£è¤ø¶.Table Component-®¬ù
ï£ñ¢ ðòù¢ð´î¢î «õí¢´ñ£ù£ô¢ ºîô¤ô¢ javax.swing.table.* âù¢ø Package
-¬ù import ªêò¢ò «õí¢´ñ¢.
Þ颰 Table âù¢ªø£¼ class â¿î¤ò¤¼è¢è¤ù¢«ø£ñ¢. main function-ô¢ ޼
å¼ ¹î¤ò Object-¬ù à¼õ£è¢°è¤ù¢«ø£ñ¢.Üð¢ªð£¿¶ ïñ袰 Constructor function
Þò颰è¤ù¢ø¶. Üî¤ô¢ ï£ñ¢ ºîô¤ô¢
JFrame frame = new JFrame(‘Table’);
âù¢Á ªè£´î¢¶ å¼ frame-¬ù à¼õ£è¢è¤è¢ ªè£÷¢è¤«ø£ñ¢. ð¤ù¢ final String [
] names... âù¢Á ªè£´î¢¶ å¼ String array ò¤¬ù à¼õ£è¢è¤ Üî¤ô¢ ïñ¶
Table -ô¢ õó ޼袰ñ¢ Title-è÷¤ù¢ ªðòó¢è¬÷ð¢ ðî¤è¢è¤ù¢«ø£ñ¢. ܴ final
object [ ][ ] data ....... âù¢Á ªè£´î¢¶ å¼ array ò¤¬ù à¼õ£è¢è¤ Üî¤ô¢ ïñ¶
Table ø¢° «î¬õò£ù îèõô¢è÷¢ ܬùî»ñ¢ õó¤¬êò£è ðî¤ï¢¶
¬õî¢î¤¼è¢ è¤ù¢«ø£ñ¢. Þï¢î Object data type ¬ùð¢ ðòù¢ð´î¢î¤«ò Table
Java-15](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-113-320.jpg)
![124
Listing 6.1
import java.sql.*;
class jdbcdemo
{
public static void main(String ag[])
{
int sno;
String sname;
int tam,eng,maths,tot;
String url=”jdbc:odbc:arshad”;
try
{
Class.forName(“sun.jdbc.odbc.JdbcOdbcDriver”);
// initialise
Connection cn=DriverManager.getConnection(url,””,””);
// establishing a connection
String sql=”select sno,sname,tamil,english,maths from
student”;
// forming a query
System.out.println(cn.nativeSQL(sql));
Statement s1=cn.createStatement();
// creating a statement object, whill will maintain transactions
ResultSet rs=s1.executeQuery(sql);
// executing a query and holds the data
while(rs.next()) // skips next record
{
sno=rs.getInt(1); // retriving the fields...
sname=rs.getString(2);
tam=rs.getInt(3);
eng=rs.getInt(4);
maths=rs.getInt(5);
tot=tam+eng+maths;
System.out.println(sno+” “+sname+” “+tam+”](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-124-320.jpg)
![127
ðì‹ðì‹ðì‹ðì‹ðì‹ 6.7
Listing 6.2
import java.sql.*;
class jdbcstore
{
public static void main(String argv[])
{
String url=”jdbc:odbc:arshad”;
try
{
Class.forName(“sun.jdbc.odbc.JdbcOdbcDriver”);
Connection connection=
DriverManager.getConnection(url,””,””);
String sql=”insert into student values
(106,’Hameetha’,87,72,64)”;
// String sql=”delete from student”;
// String sql=”update student set sname=’Simran’ where sno=106"](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-127-320.jpg)
![134
èí¤ð¢ªð£ø¤ò¤ô¢ à÷¢÷ Clock-ô¢ âï¢î «ïóñ¢ Þ¼è¢è¤ù¢ø«î£ Üîù¢ ñî¤ð¢¹ hello
object-®ù¢ à÷¢ ðî¤ï¢¶ õ¤´è¤ù¢ø¶. Üî¬ù ï£ñ¢ hello.toString( ) function
õö¤ò£è Screen-ô¢ display ªêò¢¶ ªè£÷¢è¤ù¢«ø£ñ¢.
ªñ£î¢îî¢î¤ô¢ ¹«ó£è¤ó£ñ£ù¶ åõ¢ªõ£Á second èö¤î¢¶ paint( ) function-
ä Þò袰ñ¢ ªð£¿¶ ïñ袰 øò¤ô¢ Clock å®è¢ªè£í¢®¼ð¢ð¶ ªîó¤è¤ù¢ø¶.
ÞÁî¤ò¤ô¢ ï¦é¢è÷¢ âð¢ªð£¿¶ applet -®¬ù class ªêò¢è¤ù¢ø¦ó¢è«÷£ Üð¢ªð£¿¶
stop event î£ù£è Þò袰è¤ù¢ø¶. ÜîÂ÷¢ runner=new âù¢Á ªè£´î¢î¤¼ð¢ðîù¢
Íôñ¢ Thread-®ù¢ Þòè¢èñ¢ ï¤ù¢Á õ¤´è¤ù¢ø¶.
Listing7.2
import java.awt.*;
import java.applet.Applet;
import java.util.*;
public class anim extends Applet implements Runnable
{
Image theimage[]=new Image[10];
String dir=”Images/”;
String name=”T”;
String ext=”.gif”;
Thread runner;
int cnt=0;
public void init()
{
int i;
for (i=0;i<10;i++)
{
theimage[i]=getImage(getDocumentBase(),
dir+name+(i+1)+ext);
}
}](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-134-320.jpg)
![136
cnt=0;
}
screen.drawImage(theimage[cnt++],0,0,this);
}
}
Þï¢î ¹«ó£è¤ó£ñ£ù¶ å¼ Animation õ¼ñ£Á â¿îð¢ð좮¼è¢è¤ù¢ø¶.
ï¦é¢è÷¢ cartoon -è÷¢ ñø¢Áñ¢ ðô Graphics è£ì¢ê¤è¬÷ ªî£¬ôè¢è£ì¢ê¤è÷¤ô¢
ð£ó¢î¢î¤¼ð¢ð¦ó¢è÷¢. Üõø¢¬øªòô¢ô£ñ¢ èí¤ð¢ªð£ø¤ò¤ô¢ î£ù¢ à¼õ£è¢°
è¤ù¢ø£ó¢è÷¢ âù¢ð¶ñ¢ àé¢èÀè¢°î¢ ªîó¤»ñ¢. Þ𢹫ó£è¤ó£ñ£ù¶ Animation-è÷¢
âõ¢õ£Á â¿îð¢ð´è¤ù¢øù âù¢ðîø¢° å¼ ê¤Á â´î¢¶è¢è£ì¢´ Ý°ñ¢.
ªð£¶õ£è Animation ªêò¢»ñ¢ ªð£¿¶ ðô Image-è÷¢ «î¬õð¢ð´è¤ù¢øù.
Üî£õ¶ åõ¢ªõ£Á Animation movement-ø¢è¢°ñ¢ âù¢Á îù¤î¢îù¤ image file-è÷¢
«õí¢´ñ¢. Üï¢î file-è¬÷ å¼ °ø¤ð¢ð¤ì¢ì è£ô Þ¬ìªõ÷¤è¢°÷¢ ê¦ó£è
Display Ý°ñ¢ð® ªêò¢õ«î Animation ¹«ó£è¤ó£ñ¢ Ý°ñ¢.
Þï¢î ¹«ó£è¤ó£ñ¤¬ù ï¦é¢è÷¢ Þòè¢è «õí¢´ñ¢ âù¤ô¢ ºîô¤ô¢ gif file-
è¬÷ à¼õ£è¢è¤è¢ ªè£÷¢Àé¢è÷¢. Üõø¢ø¤ô¢ å¼ Animation à¼õ£õîø¢è¢è£ù
ªî£ìó¢ê¢ê¤ò£ù movement-è÷¢ ޼袰ñ¢ð® ð£ó¢î¢¶è¢ ªè£÷¢Àé¢è÷¢. â´î¢¶è¢
è£ì¢ì£è å¼ Bus ªð£ñ¢¬ñò£ù¶ Þìð¢ðè¢è ͬôò¤ô¤¼ï¢¶ õô¶ ðè¢èî¢î¤ø¢°
ïèó¢õ¶ «ð£ô ð ðìé¢è¬÷ õ¬ó ªè£÷¢Àé¢è÷¢. ï¦é¢è÷¢ Bmp, Gif, Jpg
ºîô¤ò âï¢î õ¬è Graphics File-è¬÷ «õí¢´ñ£ù½ñ¢ à¼õ£è¢è¤è¢
ªè£÷¢Àé¢è÷¢. Þ颰 T1.gif, T2.gif, T3.gif... âù¢Á ªðòó¢ õ¼ñ£Á ð file-
è¬÷ õ¬ó Þ¼è¢è¤ù¢«ø£ñ¢. ¹«ó£è¤ó£ñ¤ù¢ Ýóñ¢ðî¢î¤ô¢
Image theImage[ ] = new Image[10];
âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þï¢î Image Class-ù¢ object-
è÷¤ô¢ î£ù¢ ïñ¢ñ£ô¢ Graphics file -è÷£ù Bmp, Gif, Jpg ºîô£ùõø¢ø¤ô¢
Þ¼è¢è¤ù¢ø îèõô¢è¬÷ ðî¤ï¢¶ ¬õî¢¶è¢ ªè£÷¢÷ º®»ñ¢.
String dir = “Images/”;
String name= “T”;
String ext = “gif”;
âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þ¬õ º¬ø«ò file Ýù¶
âï¢î Directory-ò¤ô¢ Þ¼è¢è¤ù¢ø¶, âï¢î â¿î¢î¤ù¤ô¢ ªðòó£ù¶ Ýóñ¢ð¤è¢è¤ù¢ø¶
ñø¢Áñ¢ âù¢ù extension -ä ªè£í¢®¼è¢è¤ù¢ø¶ «ð£ù¢øõø¢¬øè¢ °ø¤è¢è¤ù¢ø¶.](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-136-320.jpg)
![140
Üî¢î¤ò£òñ¢ 8Üî¢î¤ò£òñ¢ 8Üî¢î¤ò£òñ¢ 8Üî¢î¤ò£òñ¢ 8Üî¢î¤ò£òñ¢ 8
Files
Java õ¤ô¢ java.io.file âù¢Á å¼ package Þ¼è¢è¤ù¢ø¶. Þî¤ô¢ à÷¢÷ class
è¬÷ð¢ ðòù¢ð´î¢î¤ ïñ¢ñ£ô¢ low level file operation-è¬÷ ªêò¢¶ ªè£÷¢÷ Þò½ñ¢.
Üî£õ¶ ¹î¤ò file-è¬÷ à¼õ£è¢èõ¶ ãø¢è¢ªèù«õ Þ¼è¢è¤ù¢ø file è¬÷
read ªêò¢¶ ªè£÷¢õ¶ ºîô£ù «õ¬ôè¬÷ê¢ ªêò¢¶ ªè£÷¢÷ô£ñ¢.
Listing 8.1
import java.io.File;
class FileQuery
{
public static void main(String args[])
{
String dirname=”india”;
String filename=”store.java”;
File myfile=new File(dirname,filename);
System.out.println(“File Name: “ + myfile.getName());
System.out.println(“Is it a Directory : “ +
myfile.isDirectory());
System.out.println(“It is a real file : “ + myfile.isFile());
System.out.println(“File Path: “ + myfile.getPath());
System.out.println(“Absolute File Path: “ +
myfile.getAbsolutePath());
System.out.println(“Is File Readable: “ +
myfile.canRead());
System.out.println(“Is File Writeable: “ +
myfile.canWrite());
System.out.println(“Modified on: “ +
myfile.lastModified());
System.out.println(“Size (in bytes): “ + myfile.length());
System.out.println();](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-140-320.jpg)
![141
System.out.println(“—— Directory Listing ——”);
File dir=new File(dirname);
if (dir.isDirectory()==false)
{
System.out.println(dirname + “is not a directory”);
}
else
{
System.out.println(“Directory of “ + dirname);
String d[]=dir.list();
for (int i=0; i<d.length;i++)
{
System.out.println(d[i]);
}
}
}
}
Þï¢î𢠹«ó£è¤ó£ñ¤¬ù Þòè¢è¤ù£ô¢ ï£ñ¢ âï¢î Subdirectory-ò¤ù¢ ªðòó¤¬ùè¢
ªè£´î¢î¤¼è¢è¤ù¢«ø£«ñ£, Üî¤ô¢ à÷¢÷ ܬù file-è¬÷»ñ¢ display ªêò¢¶
ªè£´è¢°ñ¢. «ñ½ñ¢ âù¢ù file name ªè£´î¢î¤¼è¢è¤ù¢«ø£«ñ£ Üï¢î file-
ù¬ð¢ ðø¢ø¤ò º¿¬ñò£ù îèõô¢è¬÷ ªðø¢Áî¢î¼ñ¢. main ( ) function- ù¢
Ýóñ¢ðî¢î¤ô¢ ºîô¤ô¢
String dirname=“india”;
String filename=“store.java”;
âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þî¤ô¢ india âù¢ð¶ Subdirectory,
åù¢ø¤ù¢ ªðòó£°ñ¢. Þîø¢°ð¢ðî¤ô¢ ï¦é¢è÷¢ â颰 Þï¢î ¹«ó£è¤ó£ñ¤¬ù Þòè¢èð¢
«ð£è¤ù¢ø¦ó¢è«÷£ Üî¤ô¢ à÷¢÷ sub directory-ò¤ù¢ ªðòó¤¬ùè¢ ªè£´î¢¶è¢
ªè£÷¢Àé¢è÷¢. ܶ «ð£ô«õ store.java âù¢ð¶ ªõ¼ñ¢ â´î¢¶è¢è£ì¢«ì. «õÁ
å¼ file ªðòó¤¬ùè¢ ªè£´î¢¶è¢ ªè£÷¢Àé¢è÷¢.
File myfile=new File(dirname, filename);
âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þï¢î File âù¢Âñ¢ class-ô¢
î£ù¢ File operation êñ¢ðï¢îð¢ðì¢ì ܬù function-èÀñ¢ Þ¼è¢è¤ù¢øù.](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-141-320.jpg)
![142
Þð¢ªð£¿¶ india âù¢Âñ¢ Subdirectory-ô¢ à÷¢÷ store.java âÂñ¢ file-ù¢ ܬù
îèõô¢èÀñ¢ º¿¬ñò£è myfile âù¢Âñ¢ object -ù¢ à÷¢ õõ¤ì¢ìù.
Þ颰 myfile.getName( ) âù¢Á ªè£´è¢°ñ¢ ªð£¿¶ file-ù¢ ªðòó¢ 褬ìè¢è¤ù¢ø¶.
myfile.isDirectory( ) âù¢Á ªè£´è袰ñ¢ªð£¿¶ file âï¢î Subdirectory-ò¤ô¢ Þ¼è¢è¤ù¢ø¶
âù¢ð¶ ªîó¤»ñ¢. myfile.isFile()âù¢Á ªè£´î¢î£ô¢ ï£ñ¢ ªè£´î¢î¤¼è¢°ñ¢ ªðòó¤ô¢ Þ¼ð¢ð¶
file î£ù£ Üô¢ô¶ Þô¢¬ôò£ âù¢ðî¬ùî¢ ªîó¤ï¢¶è¢ ªè£÷¢÷ô£ñ¢. myfile.getpath()
âù¢Á ªè£´è¢°ñ¢ file-ù¢ º¿ path 褬ìè¢è¤ù¢ø¶. myfile.canRead( ) âù¢Á ªè£´è¢°ñ¢
ªð£¿¶ file -¬ù ð®è¢è º®»ñ£ Üô¢ô¶ º®ò£î âù¢ð¶ ªîó¤»ñ¢. Ü«î«ð£ô¢
myfile.canWrite()âù¢Á ªè£´è¢°ñ¢ªð£¿¶ file-ù¤ô¢ îèõô¢è¬÷ ¹î¤î£è â¿î º®»ñ£
Üô¢ô¶ º®ò£î£ âù¢ð¶ ªîó¤»ñ¢. myfile.lastModified( ); âù¢Á ªè£´è¢°ñ¢ªð£¿¶ file-
¬ù è¬ìê¤ò£è ï£ñ¢ âï¢î «îî¤ ñø¢Áñ¢ «ïóî¢î¤ô¢ ðòù¢ð´î¢î¤«ù£ñ¢ âù¢ø îèõô¢è÷¢
褬ìè¢è¤ù¢øù.
ܴ File dir=new File(dirname); âù¢Á ªè£´î¢î¤¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. ï£ñ¢
ªè£´î¢î¤¼è¢°ñ¢ ªðòó¤ô¢ å¼ Subdirectory-ò¤¼ð¢ð¤ù¢ dir.isDirectory( ) function Ýù¶ true
âù¢Á ªè£´è¢°ñ¢. Üð¢ªð£¿¶ if condition- ù¤ô¢ else ð°î¤ Þò颰ñ¢. Ü颰 String d[ ] =
dir.list( ); âù¢Á ªè£´î¢î¤¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þîù¢ Íôñ¢ ï£ñ¢ ªè£´î¢î Sub
directoryò¤ù¢ ܬù file-è÷¤ù¢ ªðòó¢èÀñ¢ d âù¢Âñ¢ String array ò¤ô¢ ðî¤è¤ù¢øù.
Üõø¢¬ø loop-ù¢ Íôñ¢ ï£ñ¢ display ªêò¢¶ ªè£÷¢è¤ù¢«ø£ñ¢.
ðì‹ðì‹ðì‹ðì‹ðì‹ 8.1](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-142-320.jpg)
![143
Listing 8.2
import java.io.*;
class LineByLine
{
public static void main(String args[])
throws FileNotFoundException
{
String filename=”FileQuery.java”;
FileInputStream f=new FileInputStream(filename);
LineNumberInputStream filestream=new
LineNumberInputStream(f);
try
{
int c;
System.out.print(“Line 1:”);
while ((c=filestream.read())!= -1)
{
System.out.print((char)c);
if (c==’n’)
{
System.out.print(“Line “ +
(filestream.getLineNumber()+1) + “:”);
}
}
}catch(IOException e)
{
System.out.println(“Can’t open stream!”);
}
}
}](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-143-320.jpg)
![144
Þï¢î ¹«ó£è¤ó£ñ¤ù¤ô¢ å¼ text file-ô¢ à÷¢÷ ܬù õó¤è¬÷»ñ¢ read
ªêò¢¶ display ªêò¢õîø¢°ð¢ ¹«ó£è¤ó£ñ¢ â¿îð¢ð좴÷¢÷¶.
ºîô¤ô¢ main( ) function ù¤ù¢ ªî£ìó¢ê¢ê¤ò£è throws FileNotFoundException
âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þîù¢ Íôñ¢ ï£ñ¢ ªè£´è¢è¤ù¢ø
file Ýù¶ êó¤ò£è open Ýèõ¤ô¢¬ô ªòù¤ô¢ Can’t open Stream; âù¢Á error
õ¼ñ£Á ¹«ó£è¤ó£ñ¤ù¢ è¬ìê¤ò¤ô¢ exception ܬñè¢èð¢ð좮¼è¢è¤ù¢ø¶
File IntputStream f= new FileInputStream(filename);
LineNumberInputStream filestream = new LIneInputStream(f);
âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¬îè¢ class Ýù¶ å¼ file-ô¢ à÷¢÷ â¿î¢¶è¢è¬÷
read ªêò¢õîø¢è¢° àî¾è¤ù¢ø¶. ï£ñ¢ Þ颰 FileQuery.java âù¢Âñ¢ textfile-ô¢
à÷¢÷ îèõô¢è¬÷ read ªêò¢ò Þ¼è¢è¤ù¢«ø£ñ¢. ï¦é¢è÷¢ àé¢èÀ袰 «õí¢®ò
file-è÷¤ù¢ªðòó¤¬ùè¢ Þ颰 ªè£´î¢¶è¢ ªè£÷¢Àé¢è÷¢. LineNumberInput
StreamÝù¶ file-ô¢ îø¢ªð£¿¶ ï£ñ¢ âï¢î Line-ô¢ Þ¼è¢è¤ù¢«ø£ñ¢ âù¢ø
îèõ¬ô𢠪ðø¢Áî¢îóè¢Ã®ò getLineNumber( ) function Þ¼ð¢ðîù£ô¢
ðòù¢ð´î¢¶è¤ù¢«ø£ñ¢.
while((c=filestream.read())!=-1)
âù¢Á ªè£´î¢î¤¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þ颰 read( ) function Ýù¶ file-ô¢
à÷¢÷ åõ¢ªõ£Á â¿î¢î£è read ªêò¢¶ ªè£´è¢è¤ù¢ø¶. å¼ â¿î¢¶ read
ªêò¢òð¢ðì¢ì¾ìù¢ file pointer Ýù¶ Ü´î¢î â¿î¢î¤ø¢° î£ù£è ªêù¢Á õ¤´ñ¢.
âð¢ªð£¿¶ end of file-ø¢è¢° õ¼è¤ù¢«ø£«ñ£ Üð¢ªð£¿¶ -1 âù¢ø ñî¤ð¢ð¤¬ùð¢
ªðÁ«õ£ñ¢. Üð¢ªð£¿¶ loop-¬ù õ¤ì¢´ ªõ÷¤ò¤ô¢ õ õ¤´«õ£ñ¢. loop-ù¢
à÷¢ System.out.print ((char)c); âù¢Á ªè£´ð¢ðîù¢Íôñ¢ åõ¢ªõ£Á â¿î¢î£è
display Ýè¤ù¢ø¶.
Listing 8.3
import java.io.*;
class copycharacters
{
public static void main(String args[])
{
File infile=new File(“FileQuery.java”);
File outfile=new File(“output.dat”);
FileReader ins=null;](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-144-320.jpg)
![148
GridBagLayout gl=new GridBagLayout();
GridBagConstraints gc=new GridBagConstraints();
void assign (GridBagConstraints abc,int gx,int gy,int gw,int gh,int
wx,int wy,int fi,int ga)
{
abc.gridx=gx;
abc.gridy=gy;
abc.gridwidth=gw;
abc.gridheight=gh;
abc.weightx=wx;
abc.weighty=wy;
abc.fill=fi;
abc.anchor=ga;
}
Choice c_month=new Choice();
Label l_month=new Label(“Month”);
Label l_year=new Label(“year”);
TextField txt_year=new TextField(4);
String[] a_month={“January”,”February”,”March”,”April”,
”May”,”June”,”July”,”August”,“September”,”October”,”November”,”December”};
String[] a_days={“Sun”,”Mon”,”Tue”,”Wed”,”Thur”,
”Fri”,”Sat”};
String[] a_dates={“1”,”2",”3",”4",”5",”6",”7",”8",”9",”10",
“11”,”12",”13",”14",”15",”16",”17",”18",”19",”20",“21”,”22",”23",
”24",”25",”26",”27",”28",”29",”30",”31"};
int[] x_row={100,150,200,250,300,350,400};
int[] x_col={100,150,200,250,300,350,400};
Button up,down;
int my_count,my_month,my_year,my_day,txin;
public void init()
{
mydate=new Date();
for(int i=0;i<a_month.length;i++)
{](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-148-320.jpg)
![149
c_month.addItem(a_month[i]);
}
up=new Button(“>”);
down=new Button(“<“);
setLayout(gl);
assign(gc,0,0,1,1,100,100,GridBagConstraints.NONE,
GridBagConstraints.NORTHEAST);
gl.setConstraints(l_month,gc);
add(l_month);
assign(gc,1,0,1,1,100,100,GridBagConstraints.NONE,
GridBagConstraints.NORTHEAST);
gl.setConstraints(c_month,gc);
add(c_month);
assign(gc,2,0,1,1,100,100,GridBagConstraints.NONE,
GridBagConstraints.NORTHEAST);
gl.setConstraints(l_year,gc);
add(l_year);
assign(gc,4,0,1,1,100,100,GridBagConstraints.NONE,
GridBagConstraints.NORTHEAST);
gl.setConstraints(txt_year,gc);
add(txt_year);
int year=mydate.getYear()+1900;
txt_year.setText(“”+year);
txt_year.setEditable(false);
assign(gc,5,0,1,1,100,100,GridBagConstraints.NONE,
GridBagConstraints.NORTHEAST);
gl.setConstraints(up,gc);](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-149-320.jpg)
![150
add(up);
assign(gc,3,0,1,1,100,100,GridBagConstraints.NONE,
GridBagConstraints.NORTHEAST);
gl.setConstraints(down,gc);
add(down);
c_month.select(a_month[mydate.getMonth()]);
my_month=mydate.getMonth();
if(my_month==0)
my_count=31;
else
if(my_month==1)
{
int ef=Integer.parseInt(txt_year.getText());
if(ef%4==0)
my_count=29;
else
my_count=28;
}
else if(my_month==2)
my_count=31;
else if(my_month==3)
my_count=30;
else if(my_month==4)
my_count=31;
else if(my_month==5)
my_count=30;
else if(my_month==6)
my_count=31;
else if(my_month==7)
my_count=31;
else if(my_month==8)
my_count=30;](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-150-320.jpg)
![151
else if(my_month==9)
my_count=31;
else if(my_month==10)
my_count=30;
else if(my_month==11)
my_count=31;
repaint();
}
public void paint(Graphics g)
{
my_day=1;
int ab=Integer.parseInt(txt_year.getText());
my_year=ab-1900;
mydate.setDate(my_day);
mydate.setYear(my_year);
mydate.setMonth(my_month);
for(int i=0;i<a_days.length;i++)
{
g.drawString(a_days[i],x_col[i],75);
}
int x=mydate.getDay();
int y=0;
for(int j=0;j<my_count;j++)
{
g.drawString(a_dates[j],x_col[x],x_row[y]);
x++;
if (x>6)
{
y++;
x=0;
}
}
}](https://image.slidesharecdn.com/java-130623222054-phpapp01/85/Java-151-320.jpg)
Java
- 1. âOò îIN™âOò îIN™âOò îIN™âOò îIN™âOò îIN™ JAVA ð £ ‚ A ò ï £ î ¡ð £ ‚ A ò ï £ î ¡ð £ ‚ A ò ï £ î ¡ð £ ‚ A ò ï £ î ¡ð £ ‚ A ò ï £ î ¡
- 2. ELIYATHAMIZHIL- JAVA By BAKIYANATHAN Published By: Bakkiam Consultancy Services (BCS) Old No: 60, New No: 127, Angappa Naicken Street, Parrys, Chennai-600001 All Rights Reserved by BCS
- 3. âOò îIN™âOò îIN™âOò îIN™âOò îIN™âOò îIN™ JAVA ¹°‹º¡:¹°‹º¡:¹°‹º¡:¹°‹º¡:¹°‹º¡: îèõ™ ªî£N™ ¸†ðˆ ¶¬øJ™ å¼ ¹Fò ñÁñô˜„CJ¬ù ãŸð¢ð´ˆFò ªñ£N JAVA â¡ø£™ ܶ I¬èò£è£¶. Iè‚ °ÁAò è£ôˆF™ àôè‹ º¿õ¶‹ HóCˆî‹ ªðŸÁ ð™«õÁ ܽõôèƒèO½‹ Þ¡Á JAVA ðò¡ð´ˆîŠð´Aø¶. JAVA -M¡ Þ‰î Mòˆî° õ÷˜„C‚° Internet -¡ ðò¡ð£´èœ èì‰î Cô ݇´èO™ ÜFèKˆî«î è£óíñ£°‹. ãªùQ™ JAVA -M™ Internet -ä„ ê£˜‰î ¹«ó£Aó£‹è¬÷ âO¬ñò£è â¿î Þò½‹. «ñ½‹ âŠð®Šð†ì Application Program -è¬÷ «õ‡´ñ£ù£½‹ â¿F‚ ªè£œ÷ Þò½‹. ÞõŸ¬ø M쾋 JAVA Hóðôñ£ù º‚Aò è£óí‹ å¡Á Þ¼‚Aø¶. ܶ JAVA Þôõêñ£è A¬ì‚A¡ø¶. Þî¬ù Internet -™ Þ¼‰¶ Þôõêñ£è Download ªêŒ¶‚ ªè£œ÷ô£‹. Þ‰î ¹ˆîèˆF™ JAVA -M¡ ܬùˆ¶Š ðò¡ð£´è¬÷»‹ Iè ªîOõ£è Cø‰î â´ˆ¶‚裆´èœ Íô‹ M÷‚AJ¼‚A«ø¡. Þî¡ Ü®Šð¬ì‚ «è£†ð£´èO™ Þ¼‰¶ ¸µ‚èñ£ù ܬùˆ¶ ¹«ó£Aó£Iƒ º¬øèÀ‹ ÞQò îIN™ âOò ï¬ìJ™ M÷‚èŠð†´œ÷ Þ‰î ¹ˆîè‹ îƒèÀ‚° I°‰î ðòùO‚°‹ â¡Á à÷ñ£ø A«ø¡. õ£›ˆ¶‚èÀì¡,õ£›ˆ¶‚èÀì¡,õ£›ˆ¶‚èÀì¡,õ£›ˆ¶‚èÀì¡,õ£›ˆ¶‚èÀì¡, ð £ ‚ A ò ï £ î ¡ð £ ‚ A ò ï £ î ¡ð £ ‚ A ò ï £ î ¡ð £ ‚ A ò ï £ î ¡ð £ ‚ A ò ï £ î ¡
- 4. 4 ªð£¼÷ìè¢èñ¢ªð£¼÷ìè¢èñ¢ªð£¼÷ìè¢èñ¢ªð£¼÷ìè¢èñ¢ªð£¼÷ìè¢èñ¢ âíâíâíâíâí¢¢¢¢¢ Üî¢î¤ò£òñ¢Üî¢î¤ò£òñ¢Üî¢î¤ò£òñ¢Üî¢î¤ò£òñ¢Üî¢î¤ò£òñ¢ ðè¢èñðè¢èñðè¢èñðè¢èñðè¢èñ¢¢¢¢¢ 1 Java - ºîô¢ ð£ó¢¬õºîô¢ ð£ó¢¬õºîô¢ ð£ó¢¬õºîô¢ ð£ó¢¬õºîô¢ ð£ó¢¬õ 5 2 Object-Oriented Programming 23 3 Applets ñø¢Áñ¢ñø¢Áñ¢ñø¢Áñ¢ñø¢Áñ¢ñø¢Áñ¢ Application 42 4 JavaDraw å¼ º¿¬ñò£ùå¼ º¿¬ñò£ùå¼ º¿¬ñò£ùå¼ º¿¬ñò£ùå¼ º¿¬ñò£ù Drawing ¹«ó£è¤ó£ñ¢¹«ó£è¤ó£ñ¢¹«ó£è¤ó£ñ¢¹«ó£è¤ó£ñ¢¹«ó£è¤ó£ñ¢ 74 5 Swing - Java Foundation Classes (JFC) 95 6 Java Database Connectivity (JDBC) 120 7 Thread 130 8 Files 140 9 Calander - ¹«ó£è¤ó£ñ¢¹«ó£è¤ó£ñ¢¹«ó£è¤ó£ñ¢¹«ó£è¤ó£ñ¢¹«ó£è¤ó£ñ¢ 147
- 5. 5 Üî¢î¤ò£òñ¢Üî¢î¤ò£òñ¢Üî¢î¤ò£òñ¢Üî¢î¤ò£òñ¢Üî¢î¤ò£òñ¢ 1. Java - ºîô¢ ð£ó¢¬õºîô¢ ð£ó¢¬õºîô¢ ð£ó¢¬õºîô¢ ð£ó¢¬õºîô¢ ð£ó¢¬õ õóô£Áõóô£Áõóô£Áõóô£Áõóô£Á Sun Micro System â¡Â‹ ܪñK‚è GÁõù‹ 1991 -‹ ݇´ õ£‚A™ Java ªñ£NJ¬ù à¼õ£‚Aò¶. ܉î è£ô è†ìˆF™ ܉GÁõù‹ TV, VCR ºîLò âªô‚®ó£Q‚ àðèóíƒèO™ ðò¡ðì‚îò ªñ¡ ªð£¼œè¬÷ à¼õ£‚°‹ ºòŸCJ™ Þ¼‰î¶. Ü âO¬ñò£è¾‹, «õèñ£è¾‹, I辋 FøÂœ÷î£è¾‹ ñŸÁ‹ CPòî£è¾‹ Þ¼‚è‚îò ¹«ó£Aó£‹èœ «î¬õŠð†ìù. «ñ½‹ ܬõ ܬùˆ¶ õ¬èò£ù Hardware àðèóíƒèO½‹ ðò¡ðì‚îòî£è¾‹ Þ¼‚è «õ‡®ò ÜõCòI¼‰î¶. Þ‰î ܬùˆ¶ âF˜ð£˜Š¹è¬÷»‹ ̘ˆF ªêŒ»‹ õ¬èJ™ Java ªñ£NJ¬ù à¼õ£‚Aù£˜èœ. Java -ªñ£NJ¬ù ð™«õÁ ¹«ó£ªü†èO™ Sun GÁõùˆî£˜ ðò¡ð´ˆFJ¼‚A¡øù˜, â¡ø£½‹ 1994 -‹ õ¼ì‹ Hot Java Browser â‹ ªñ¡ªð£¼œ ªõOò£ù ªð£¿¶î£¡ Þ¶ Hóðôñ¬ì‰î¶. Java Development Kit (JDK) Java â‹ ªê£™ Java Development Kit â¡ðî¬ù«ò °P‚A¡ø¶. Kit â¡Â‹ ªê£™LŸ° ð™ªõÁ ªð£¼œè¬÷ ªè£‡ì ªî£°Š¹ â¡Á ªð£¼œ. Java -M™ ð™ªõÁ «õ¬ôè¬÷ ªêŒõîŸè£è îQˆîQò£è ðô Tool -èœ Þ¼‚A¡øù. ÜõŸP¡ Æ´ˆ ªî£°Š«ð Java Development Kit Ý°‹. àî£óíñ£è cƒèœ å¼ Java ¹«ó£Aó£I¬ù à¼õ£‚AJ¼‚A¡l˜èœ â¡ø£™ Üî¬ù Compile ªêŒõè¡Á javac â‹ Compiler Tool Þ¼‚A¡ø¶. Þî¡ Íô‹ Compile ªêŒòŠð†´ à¼õ£‚èŠð´‹ Object File- è¬÷ Þò‚°õ java â¡Â‹ Tool Þ¼‚A¡ø¶. Þ¶«ð£¡Á æõ¢ªõ£Á ðE‚° â¡Á îQˆîQò£è Tool -èœ Þ¼‚A¡øù. Þ‰î Tool -èO¡ ªî£°Š«ð Java. Þ‰î JDK -¡ ð£¬îò Version Ýù¶ 1.2 Ý°ñ¢. Üî£õ¶ JDK 1.2 -õ¤¬ù   Java Version 2 â¡Á ܬö‚A¡«ø£‹. Þ‰î JDK1.2-õ¤¬ù  Sun Micro System -F¡ http://Java.Sun.com Þ¬íò î÷ˆFL¼‰¶ Þôõêñ£è Download ªêŒ¶ ªè£œ÷ Þò½‹. Þ‰î JDK -õ¤¬ùî¢ îM˜ˆ¶ «õÁ Cô Java -èÀ‹ Þ¼‚A¡øù. ÜõŸ¬øŠ ðŸP»‹ cƒèœ ÜP‰¶ ªè£œ÷ «õ‡´‹. ܶ Þ¡Pò¬ñò£î¶.
- 6. 6 Microsoft Visual J++ Borland JBuilder Symantec Cafe Lite ºîô£ù ªñ¡ªð£¼œè¬÷Š ðŸP «èœMŠð†®¼‚Al˜è÷£. Þ¬õ»‹ Java ªñ£Nèœî£¡. Ýù£™ Þ¬õ Integrated Development Environment (IDE) â¡Â‹ õ¬èJ¬ù ꣘‰î Sun Micro System îM˜ˆ¶ ð¤ø 苪ðQè÷£™ MŸ‚èŠð´‹ ªñ¡ªð£¼œ Ý°‹. Integrated Development Environment â¡ð¶ º¿‚è º¿‚è ²ôðñ£ù º¬øJ™ Visual Basic ºîô£ù ªñ¡ªð£¼œèO™ ¹«ó£Aó£‹è÷¢ ⿶õ¶ «ð£ù¢ø º¬øò£°ñ¢. «ñø¢ªê£ù¢ù Java -è÷¤ô¢ ¹«ó£è¤ó£ñ¢è÷¢ â¿îõ¶ ªõ° ²ôðñ£è Þ¼‚°‹. Üî£õ¶ «õ‡®ò Object -è¬÷ Windows -™ Mouse -¡ ¶¬í‚ ªè£‡´ õ¬ó‰¶ «î¬õò£ù property setting -°è¬÷ ªêŒ¶‚ ªè£œ÷ º®»‹. Ýù£™ JDK1.2 -ä ðò¡ð´ˆ¶«õ£«ñò£ù£™ º¿‚è º¿‚è ܬùˆFŸ°‹  ¹«ó£Aó£‹è¬÷ â¿Fò£è «õ‡´‹. Þ‰î𢠹ˆîèˆF™ JDK1.2 -ä ªè£‡«ì ܬùˆ¶ â´ˆ¶‚ 裆´è¬÷»‹ ªêŒF¼‚A¡«ø£‹. Java -ä cƒèœ Þ¬íò î÷ˆFL¼‰¶ Download ªêŒî£½‹ êK Ü™ô¶ 㟪èù«õ CD-ROM -™ Þ¼‰¶ Copy ªêŒî£½‹ ÜõŸ¬ø ºîL™ Decompress ªêŒò «õ‡´‹. Java ªð£¶õ£è àƒèœ èEªð£PJ™ C:JDK1.2> â¡ø Sub Directory - ò¤ô¢ Install ÝAJ¼‚°‹. Java âù¢ø£ô¢ Java Development Kit â¡Á 㟪èù«õ ÜP‰F¼‚A¡«ø£‹. C:JDK1.2> â¡ø Sub Directory à¼õ£‚èŠð†´ ÜF™ W«ö ªè£´‚èŠð†®¼‚°‹ ܬùˆ¶ Tool -èÀ‹ Install ÝAJ¼‚°‹. Þ¬õ 嚪õ£¡Á‹ å¼ °PŠH†ì «õ¬ôè¢è£è ðò¡ð´A¡øù. ܆ìõ¬í܆ìõ¬í܆ìõ¬í܆ìõ¬í܆ìõ¬í 1.1 TOOL M÷‚è‹M÷‚è‹M÷‚è‹M÷‚è‹M÷‚è‹ Appletviewer Java -™ â¿îŠð´‹ Applet â‹ õ¬èJ¬ù ꣘‰î ¹«ó£Aó£‹èœ ê K ò £ è Þòƒ°A¡øùõ£ â¡ðî¬ù êK𣘊ð ðò¡ð´‹ Tool Ý°‹. ªð£¶õ£è Applet -èœ Browser -èO™ Þòƒ°‹ â¡ðî¬ù G¬ùM™ ªè£œè.
- 7. 7 Jar Þ¶ Java Archive Tool âùŠð´‹. Þî¡ Íô‹ ðô Java File -è¬÷ å«ó å¼ Java Archive File (Jar) Ýè ñ£ŸP‚ ªè£œ÷ Þò½‹. Java Þ¶ Java Interpreter Ý°‹. Þî¡ Íô‹ Java ¹«ó£Aó£‹è¬÷ Þò‚°A¡«ø£‹. Javac Þ¶ Java Compiler Ý°‹. Þî¡ Íô«ñ Java ¹«ó£Aó£‹è¬÷ Compile ªêŒA¡«ø£‹. Java doc Þ¶ å¼ Documentation Generator Ý°‹. Þî¡ Íô‹ Source Code -èO™ Þ¼‰¶ File-è¬÷ à¼õ£‚è Þò½‹. Javah Þ¶ ð£ó‹ðKò C ªñ£N File Generator Ý°‹. Þî¡ Íô‹ C ªñ£NJ¡ Header File -èœ ñŸÁ‹ Source File -èœÝAòõŸ¬ø à¼õ£‚è Þò½‹. Java Key Þ¶ Java Digital Key Tool Ý°‹. Þ¶ Jar File -èO™ Digital signature -è¬÷ à¼õ£‚°õð¢ ðò¡ ð´Aø¶. Javap Þ¶ å¼ Disassambler Ý°‹. Þî¡ Íô‹Java Byte Code- è¬÷  ¹K‰¶‚ªè£œÀ‹ õ®õˆF™ ñ£ŸP‚ ªè£œõŠ ðò¡ð´Aø¶. Jdb Þ¶ å¼ debugger Ý°‹. Java ¹«ó£Aó£I™ àœ÷ îõÁè¬÷ Command Line -™ Þ¼‰¶ ªè£í¢´ F¼ˆ¶õð¢ ðò¡ð´Aø¶. Jve Þ¶ Java Runtime Interpreter Ý°‹. Java Tool -ä «ð£ô Þî¬ùŠ ðò¡ð´ˆF»‹ Application -è¬÷ Þò‚A‚ ªè£œ÷ô£‹. Ýù£™ Java Tool -™ Þ¼‚è îò ðô Option -èœ ÞF™ Þ™¬ô. Native2ascii Non Unicode Latin -1 õ¬è¬ò ꣘‰î Source File è¬÷ Unicode Latin -1 File -è÷£è ñ£ŸÁõð¢ ðò¡ð´A¡ø¶. Rmtc Þ¶ Remote Method Invocation Complier Ý°‹. Þî¡ Íô‹ Stub ñŸÁ‹ Sklleton Class File -èœ Java object -èÀè¢è£è à¼õ£‚èð†´ ÜõŸ¬ø
- 8. 8 Java rmi Remote â‹ Interface -™ ðò¡ð´ˆî Þò½‹. Rmiregistry Þ¶ å¼ Remote object registry tool Ý°‹. «ñ½‹ Þ¶ RMI Server -èO™ BootStrap naming Service- è¬÷ê¢ ªêŒA¡ø¶. Serial var Þ¶ Serial Version Tool Ý°‹. Þî¡ Íô‹ Serial Verion UIP â‹ ñFŠH¬ù ܬùˆ¶ Class- èO™ Þ¼‰¶‹ ªðŸÁ‚ ªè£œ÷ º®»‹. cƒèœ ªõŸPèóñ£è Java -¬õ àƒèœ èEŠªð£PJ™ Install ªêŒîHø° Cô Environment Variable -è÷¤ô¢ ñ£ø¢øé¢è÷¢ ªêŒò «õ‡´‹. Üî£õ¶ àƒèœ Autoexec.bat File -™ Java â‰î Sub directory -™ Þ¼‚A¡ø¶, ÜPò Library- èœ âƒ° Þ¼‚A¡øù ºîô£ù îèõ™è¬÷ê¢ ªê£™ô «õ‡´‹. Ü W›è‡ì õKè¬÷ Autoexec.bat File -™ ñ£ŸP‚ ªè£œÀƒèœ. SET PATH= $PATH$;C:JDK1.2BIN SET CLASSPATH=C:JDK1.2Classes;C:JDK1.2 LibClasses.zi Autoexec.bat â¡ð¶ C: -™ Þ¼‚èîò ê£î£óí TextFile . Üî¬ù ãî£õ¶ å¼ ê£î£óí Text Editor -™ Open ªêŒ¶‚ ªè£œ÷ô£‹. Java -M™ â¡ù ªêŒò Þò½‹M™ â¡ù ªêŒò Þò½‹M™ â¡ù ªêŒò Þò½‹M™ â¡ù ªêŒò Þò½‹M™ â¡ù ªêŒò Þò½‹ ªð£¶õ£è Java -õ¤ô¢ Applet ñŸÁ‹ Application ÝAò Þó‡´ õ¬è ¹«ó£Aó£‹è¬÷ à¼õ£‚°A¡«ø£‹. Applet â¡ð¶ Internet Browser -èO™ Þòƒèîò¶. ²¼ƒèè¢ÃP¡ Internet -™ ðò¡ð´‹ ¹«ó£Aó£‹èœ. Application â¡ð¶ ê£î£óíñ£è  ⿶‹ ñŸø â™ô£ ¹«ó£Aó£‹è¬÷»‹ °P‚°‹. ºî™ºî™ºî™ºî™ºî™ Java ¹«ó£A󣋹«ó£A󣋹«ó£A󣋹«ó£A󣋹«ó£Aó£‹ Þƒ«è W«ö ªè£´‚èŠð†®¼‚°‹ ¬ìò ºî™ Java ¹«ó£Aó£I¬ù ÜŠð®«ò ãî£õ¶ å¼ Text Editor -™ ¬ìŠ ªêŒ¶ ªè£œÀƒèœ. H¡ù˜ Ü First.Java â¡Á ªðòK†´ Save ªêŒ»ƒèœ.
- 9. 9 first.java class first { public static void main (String arg[ ]) { System.out.println(“Welcome to the world of Java”); } } MS-DOS Prompt -Ÿ° õ‰¶M´ƒèœ. Ü Start--->Program--->Ms-Dos Prompt â‹ è†ì¬÷¬òŠ ðò¡ð´ˆ¶ƒèœ. ðì‹ðì‹ðì‹ðì‹ðì‹ 1.1 Þšõ£Á Þ™¬ôªòQ™ Windows -¡ Start Menu -M™ àœ÷ Run è†ì¬÷¬ò AO‚ ªêŒ»ƒèœ. ܃° ðì‹ðì‹ðì‹ðì‹ðì‹ 1.2
- 10. 10 «ñ«ô àœ÷õ£Á Command â¡Á ¬ìŠ ªêŒ»ƒèœ. ÞŠªð£¿¶ MS-DOS Prompt -Ÿ° õ‰¶ Þ¼Šd˜èœ ܃° cd jdk1.2 â¡Á ¬ìŠ ªêŒ»ƒèœ. jdk1.2 â‹ Folder -‚°œ ªê¡Á M´ƒèœ. Þ‰î Folder -™  cƒèœ àƒèœ Source File - è¬÷ à¼õ£‚AJ¼‚A¡l˜èœ â¡Á ¬õˆ¶‚ ªè£‡ì£™ ÞƒA¼‰¶ C:JDK1.2>edit first.java â¡Á ¬ìŠ ªêŒ»ƒèœ. Edit â¡Á MS-DOS -™ Þ¼‚°‹ å¼ Text Editor Ý°‹. Üî¬ùŠ ðò¡ð´ˆF  ¬ìò Java Source Code - è¬÷ â¿F ªè£œ÷ Þò½‹. ðì‹ðì‹ðì‹ðì‹ðì‹ 1.3 Þƒ° ¹«ó£Aó£I¬ù ¬ìŠ ªêŒ¶ Save ªêŒ¶ M†´ ªõOJ™ õ‰¶ M´ƒèœ. ÞŠªð£¿¶  ¬ìŠ ªêŒî Source File -ä Compile ªêŒò «õ‡´‹. Ü javac â¡Â‹ Tool ðò¡ð´Aø¶. W«ö è‡ìõ£Á è†ì¬÷¬ò‚ ªè£´ƒèœ.
- 11. 11 C:JDK1.2 >javac first.java Þ‰î javac â¡Â‹ Compiler Tool Ýù¶ ¬ìò ¹«ó£Aó£‹ º¿õ¬î»‹ Compile ªêŒ¶ Üî¬ù Byte coded class file Ýè à¼õ£‚Aˆ î¼A¡ø¶. Þð¢ªð£¿¶ first.class âù¢Âñ¢ ¹î¤ò file åù¢Á à¼õ£è¤ò¤¼è¢°ñ¢. ܉î file -ä   Þò‚è «õ‡´‹. Ü H¡õ¼ñ£Á è†ì¬÷¬ò‚ ªè£´ƒèœ. C: JDK1.2> java first Þƒ° java â¡Â‹ Tool, First â¡Â‹ Byte coded Class File -ä Þò‚°A¡ø¶. 𣿶 cƒèœ W«ö 裇𶠫ð£¡ø å¼ Result-ä 裇d˜èœ. Welcome to the world of Java °PŠ¹°PŠ¹°PŠ¹°PŠ¹°PŠ¹ Java ¹«ó£Aó£‹è¬÷ â‰î Text Editor -™ «õ‡´ñ£ù£½‹ à¼õ£‚èô£‹. Ýù£™ Ü extention Ýù¶ è†ì£òñ£è .java â¡Á Þ¼‚è «õ‡´‹. Þšõ£Á à¼õ£‚èŠð†ì Source File -ä javac â¡Â‹ Compiler Íô‹ Compile ªêŒò «õ‡´‹. ¹«ó£Aó£I™ ãî£õ¶ îõÁèœ Þ¼‰î£™ Compiler ܉î îõÁè¬÷è¢ è£ì¢´‹. Üõø¢¬øê¢ êó¤ ªêò¢¶ e‡´‹ Compile ªêŒò «õ‡´‹. îõÁèœ õó£î ð†êˆF™ java â¡Â‹ Tool -ä ªè£‡´ class file -è¬÷ Þò‚A‚ ªè£œ÷ô£‹. Java Language Cô Ü®Šð¬ì ¹«ó£Aó£Iƒ º¬øèœCô Ü®Šð¬ì ¹«ó£Aó£Iƒ º¬øèœCô Ü®Šð¬ì ¹«ó£Aó£Iƒ º¬øèœCô Ü®Šð¬ì ¹«ó£Aó£Iƒ º¬øèœCô Ü®Šð¬ì ¹«ó£Aó£Iƒ º¬øèœ ªð£¶õ£è â‰î èEŠªð£P ªñ£NJ™ ¹«ó£Aó£‹è¬÷ â¿Fù£½‹, ¹«ó£Aó£‹èO™ ° º‚Aò àì¢ÃÁèœ Þ¼‚A¡øù. cƒèœ C, C++, Oracle, Visual Basic â¡Á â‰î ªñ£NJ™ ¹«ó£Aó£‹è¬÷ ÞòŸPù£½‹ ÜõŸP™ âˆî¬ù õKèœ Þ¼‰î£½‹ ܬõò¬ùˆ¶‹ W›è£µ‹ Þ‰î ° HK¾èO™ õ‰¶ M´‹. ܬõ 1) Statements 2) Conditions 3) Branchings 4) Loopings Statements ¹«ó£Aó£I™  ðò¡ð´ˆ¶‹ 嚪õ£¼ è†ì¬÷»‹ å¼ Statements Ý°‹. cƒèœ å¼ Variable -ô¤¬ù à¼õ£‚èô£‹. Ü™ô¶ ܉î Variable-
- 12. 12 èO™ Cô ñFŠ¹è¬÷ GóŠðô£‹, ñŸÁ‹ Calculation -è¬÷ê¢ ªêŒòô£‹. Þ¶ «ð£¡Á cƒèœ ªè£´‚°‹ ðô è†ì¬÷èœ Statement -è÷£è Þ¼‚A¡øù. Conditions å¼ ¹«ó£Aó£I™ Decision Making Statements â¡ø¬ö‚èŠð´‹ è¡®û¡èœ è†ì£ò‹ Þ¼‚°‹. â´ˆ¶‚裆ì£è å¼ ðœOJ™ ñ£íõ˜èO¡ «î˜¾ ñFŠªð‡è¬÷ ¬èò£œõ å¼ ¹«ó£Aó£‹ â¿¶A¡«ø£‹ â¡Á ¬õˆ¶‚ªè£‡ì£™ ܉î ñ£íõ¡ îI›, ݃Aô‹, èEî‹, ÜPMò™, êÍè ÜPMò™ â¡Á ܬùˆ¶ ð£ìƒèO½‹ 40 Ü™ô¶ Ü «ñŸŠð†ì ñFŠªð‡è¬÷ ⴈ  «î˜„C ªðø «õ‡´‹. Þ™¬ôªòQ™ «î˜„C»øè¢Ã죶 â¡Â‹ G¬ôJ™  â¿î‚îò if condition -è¬÷«ò Conditions â¡Á ܬö‚A¡«ø£‹. è¡®û¡èœ Þ™ô£ñ™ ¹«ó£Aó£‹è÷¢ ⿶õ¬î èŸð¬ù Ãì ªêŒ¶ ð£˜‚è º®ò£¶. Branching å¼ ¹«ó£Aó£I™ ðô ¶¬íŠ ¹«ó£Aó£‹èœ (Sub Programs i.e, Procedures and Functions) â¿îŠð†®¼‚°‹. Üî£õ¶ å¼ °PŠH†ì ¹«ó£Aó£‹ â¿¶‹ªð£¿¶ º¿ ¹«ó£Aó£I¬ù»‹ ªî£ì˜„Cò£è â¿î Þòô£¶. °PŠH†ì ðEèÀ‚è£è îQˆîQò£è ¹«ó£Aó£‹è¬÷ ªõõ¢«õÁ Þìé¢è÷¤ô¢ â¿î¤è¢ ªè£÷¢÷ô£ñ¢. Þõ¢õ£Á «õÁ Þìé¢è÷¤ô¢ â¿îð¢ð좮¼è¢°ñ¢ ¹«ó£è¤ó£ñ¢è¬÷ ñŸø â‰î ¹«ó£Aó£IL¼‰¶ñ¢ Þò‚A ªè£œ÷ô£‹. Üšõ£Á Þò‚°‹ªð£¿¶ ¹«ó£Aó£‹ Ýù¶ å¼ ÞìˆF™ Þ¼‰¶ î£M ñŸªø£¼ ÞìˆFŸ° ªê¡Á ÞòƒAò H¡ e‡´‹ ð¬öò G¬ô‚° F¼‹H Þòƒ°‹ º¬øJ¬ùî¢î£¡ Branching â¡Á ÃÁA¡«ø£‹. ªð£¶õ£è ܬùˆ¶ ¹«ó£Aó£Iƒ ªñ£NèO½‹ ð™«õÁ Procedures and Functions ÝAò¬õ Þ¼‚A¡øù. ÜõŸ¬ø  Branching º¬øJ™  ðò¡ð´ˆF‚ ªè£œA«ø£‹. Looping ¹«ó£Aó£IƒA™ Loop -èO¡ ðƒ° ñèˆî£ù¶. å¼ °PŠH†ì Condition F¼ŠFð´‹ õ¬ó å¼ °PŠH†ì ¹«ó£Aó£ñ¤ù¢ õKèœ F¼‹ð F¼‹ð Þòƒ°‹ º¬øJ¬ù«ò Loop â¡Á ܬö‚A¡«ø£‹. â´ˆ¶è£†ì£è 1 -™ Þ¼‰¶ 1000 õ¬ó â‡èœ F¬óJ™ ªîKò ¬õ‚è «õ‡´ªñQ™  1000 õKè÷¤ô¢ ¹«ó£Aó£‹ â¿î Þòô£¶. Üð¢ ðFô£è å¼ Loop -¬ù
- 13. 13 ܬñˆ¶ ܉î Loop Ýù¶ 1000 îì¬õ Þòƒ°ñ£Á ܬñˆ¶ ÜîÂœ ïñ¶ ¹«ó£Aó£‹è¬÷ â¿F ªè£œ÷ «õ‡´‹. Datatypes ñŸÁ‹ñŸÁ‹ñŸÁ‹ñŸÁ‹ñŸÁ‹ Variables ïñ¶ Java ¹«ó£Aó£I™ ð™«õÁ ñFŠ¹è¬÷ ¬èò£œõ Variable- è¬÷ à¼õ£‚°«õ£‹. Üšõ£Á Variable -è¬÷ à¼õ£‚°‹ªð£¿¶ ÜõŸP™ â‰î õ¬èò£ù ñFŠ¹è¬÷ð¢ ðFò «ð£A¡«ø£‹ â¡Á Ãø «õ‡´‹. Üî¢î£¡ Datatype -èœ ðò¡ð´A¡øù. C ªñ£NJ™ Þ¼Šð¶ «ð£¡«ø Java -M½‹ int, char, float ºîô£ù Datatype -èœÞ¼è¢è¤ù¢øù. ÞõŸP™ ªõÁ‹ â‡è¬÷ ¬èò£œõ int Data Type -ä ðò¡ð´ˆ¶A¡«ø£‹. â‡èO½‹ 123.456 ºîô£ù ñFŠ¹è¬÷ð¢ ðFŠð float Data Type ðò¡ð´A¡ø¶. ⿈¶‚è¬÷ ¬èò£œõ char Data Type ðò¡ð´A¡ø¶. Þ‰î Data Type -è¬÷ îM˜ˆ¶ ð™«õÁ class -èœ Þ¼‚A¡øù. ÜõŸ¬ø‚ ªè£‡´  Variable -è¬÷ à¼õ£‚A‚ ªè£œ÷ô£‹. H¡õ¼‹ ¹«ó£Aó£I™ Cô Variable -è¬÷ à¼õ£‚A ÜõŸP™ âšõ£Á ñFŠ¹è¬÷ ðF‰¶ ¬õŠð¶ â¡ðî¬ù è£íô£‹. Listing 1.2 class pro1_2 { public static void main(String arg[]) { int rollno, tamil, english, maths, science, social, total; String sname; float avg; rollno=1; sname=”Reena”; tamil=65; english=80; maths=50; science=90; social=75;
- 14. 14 total=tamil+english+maths+science+social; avg=total/5; System.out.println(“Roll Number : “ + rollno); System.out.println(“Student Name : “ + sname); System.out.println(“Tamil : “ + tamil); System.out.println(“English : “ + english); System.out.println(“Maths : “ + maths); System.out.println(“Science : “ + science); System.out.println(“Social : “ + social); System.out.println(“Total : “ + total); System.out.println(“Average : “ + avg); } } Þ‰î ¹«ó£Aó£I™  rollno, tamil, english, maths, science, social, total ºîLò Variable -è¬÷ int data type -™ à¼õ£‚AJ¼‚A¡«ø£‹. sname â¡Â‹ Variable -ä String â¡Â‹ Class -ù¢ Object Ýè à¼õ£‚AJ¼‚A¡«ø£‹. Þ‰î String Class -ä ðò¡ð´ˆ¶õî¡ Íô‹ ªî£ì˜ ⿈¶‚è¬÷ (String °è÷¢) ¬èò£÷ô£‹. avg â¡Â‹ Variable Ýù¶ float data type -™ Þ¼‚A¡ø¶. à¼õ£‚èŠð†ì Variable -èœ Ü¬ùˆF½‹ ÜõŸPŸ‚°Pò ñFŠ¹èœ ðFòŠð†®¼‚A¡øù. ÜõŸP™ àœ÷ ñFŠ¹èœ Screen -™ Display ªêŒõîŸè£è System.out.println â¡Â‹ Function àð«ò£A‚èŠð†®¼‚A¡ø¶. cƒèœ ÞŠªð£¿¶ Ièˆ ªîOõ£è Cô Ü®Šð¬ì Java Programing º¬øè¬÷ ªîK‰¶ ªè£œ÷ «õ‡´‹. â‰î Java ¹«ó£Aó£I½‹ å¼ class â¿îŠð†®¼‚°‹. Þ‰î ¹«ó£Aó£I™ class student â¡Á ªè£´‚èŠð†®¼Šð¬îè¢ èõQ»ƒèœ. class -è¬÷Š ðŸP  ªîOõ£è H¡õ¼‹ â´ˆ¶è£†´èO½‹, ܈Fò£òƒèO½‹, è£íô£‹. ªñ£î¢îî¢î¤ô¢ å¼ Java ¹«ó£Aó£ñ£ù¶ å¼ class-¡ àœ Üì颰è¤ù¢ø¶. Þï¢î class -ù¢ à÷¢ public static void main(String arg[]) â¡ø function â¿îŠð†®¼Šð¬î èõQ»ƒèœ. Þ‰î function Þ¼ŠH¡  å¼ Java Application å¡P¬ù ⿶A¡«ø£‹ â¡Á ªð£¼œ. ¬ìò Java ¹«ó£Aó£‹ Þòƒ°‹«ð£¶ main function -™ Þ¼‰¶  Þòé¢è Ýó‹H‚°‹.
- 15. 15 H¡õ¼‹ Syntax -ä èõQ»ƒèœ. ÞF™ Þ¼Šð¶ «ð£™  cƒèœ Java Application -è¬÷ â¿î «õ‡´‹ â¡ðî¬ù G¬ùM™ ªè£œÀé¢è÷¢. class <Class Name> { public static void main(String arg[ ]) { ... } } «ñø¢è¢èí¢ì ¹«ó£è¤ó£ñ¤¬ù 覫ö ªè£´è¢èð¢ð좴÷¢÷¶ «ð£ô¢ èñ¢¬ðô¢ ªêò¢¶ Þòè¢è¤ð¢ ð£¼é¢è÷¢. ðì‹ðì‹ðì‹ðì‹ðì‹ 1.4 Operators ¹«ó£è¤ó£ñ¢è¬÷ ⿶õîø¢° Operator -è÷¤ù¢ ðé¢è÷¤ð¢¹ ñ¤è¾ñ¢ Þù¢ø¤ò¬ñò£î¶ Ýè¤ù¢ø¶. Arithmetic Operators, Relational Operators, Logical Operators âù ðô õ¬èè÷£è Operator -è÷¢ Þ¼è¢è¤ù¢øù. +, -, *, / ºîô£ù¬õ Arithmetic Operator
- 16. 16 -è÷¢ Ý°ñ¢. Þõø¢¬øè¢ ªè£í¢´ Calculation -è¬÷ê¢ ªêò¢¶ ªè£÷¢÷ô£ñ¢. <, >, <=, >=, ! =, = = ºîô£ù¬õ Relational Operator -è÷¢ Ý°ñ¢. Þõø¢ø¤ô¢ <, > âù¢ð¶ º¬ø«ò Less than ñø¢Áñ¢ Greater than âù¢ðî¬ùè¢ °ø¤è¢è¤ù¢ø¶. <=, >= Ýè¤ò¬õ º¬ø«ò Less than or equal to ñø¢Áñ¢ greater than or equal to Ýè¤òõø¢¬øè¢ °ø¤è¢è¤ù¢ø¶. ! = âù¢ð¶ not equal to âù¢ðî¬ùè¢ °ø¤è¢è¤ù¢ø¶. == âù¢ð¶ equal to âù¢ðî¬ùè¢ °ø¤è¢è¤ù¢ø¶. Þï¢î Relational Operator -è¬÷è¢ ªè£í¢´ Þóí¢´ âù¢è÷¤ô¢ ⶠªðó¤ò¶, ê¤ó¤ò¶, Üô¢ô¶ êññ£è Þ¼è¢è¤ù¢øî£ Üô¢ô¶ Þô¢¬ôò£ «ð£ù¢ø îèõô¢è¬÷ Condition - è÷¤ô¢ à÷¢ ðòù¢ð´î¢î¤ Üø¤ï¢¶ ªè£÷¢÷ô£ñ¢. &&, ||, ! ºîô£ù¬õè÷¢ Logical Operator -è÷¢ Ý°ñ¢. æù¢Á袰ñ¢ «ñø¢ðì¢ì èí¢®ûù¢è¬÷ê¢ êó¤ð£ó¢ð¢ðîø¢° Þï¢î Logical Operator -è¬÷ð¢ ðòù¢ð´î¢¶ è¤ù¢«ø£ñ¢. && âù¢ð¶ Logical AND Ý°ñ¢. Þóí¢´ Condition - è÷¢ Þ¼è¢è¤ù¢ø Þìî¢î¤ô¢ Þóí¢´«ñ èì¢ì£òñ£è Ìó¢î¢î¤ ªêò¢òð¢ðì «õí¢´ñ¢ âù¢ø 郎ôò¤ô¢ Þï¢î && (AND Operator) 郎ùð¢ ðòù¢ð´î¢î¤è¢ ªè£÷¢÷ô£ñ¢. ñ£ø£è Þóí¢´ Condition -è÷¢ Þ¼è¢è¤ù¢ø Þìî¢î¤ô¢ ãî£õ¶ åù¢Á Ìó¢î¢î¤ò£ù£ô¢ «ð£¶ñ¢ âù¢øõ£Á Þ¼ï¢î£ô¢ Üîø¢° || (OR Operator) ðòù¢ð´è¤ù¢ø¶. ! âù¢ð¶ not Operator Ý°ñ¢. if Condition ï£ñ¢ ãø¢è¢ªèù«õ Condition -âù¢ø£ô¢ âù¢ù âù¢ðî¬ùð¢ ðø¢ø¤ Üø¤ï¢î¤¼è¢è¤ù¢«ø£ñ¢. 覫ö ªè£´è¢èð¢ð좴÷¢÷ Syntax -¬ùð¢ ðòù¢ð´î¢î¤ if Condition -è¬÷ àð«ò£èð¢ð´î¢î¤è¢ ªè£÷¢÷ô£ñ¢. if (bodean Expression) { ...... } [else { ...... }] Listing 1.3 class pro1_3 {
- 17. 17 public static void main(String argv[]) { int x; int y; x=30; y=50; if (x > y) { System.out.println(“X is greater than Y”); } else if (x < y) { System.out.println(“Y is greater than X”); } else { System.out.println(“Both Are Same”); } } } Þï¢î ¹«ó£è¤ó£ñ¤ô¢ x ñø¢Áñ¢ y âù¢Á Þóí¢´ int data type variable -è÷¢ à¼õ£è¢èð¢ð좴 Üõø¢ø¤ô¢ ê¤ô ñî¤ð¢¹è¬÷ ðî¤ï¢¶ Þ¼è¢è¤ù¢«ø£ñ¢. Þ颰 if Condition -ù¤¬ùð¢ ðòù¢ð´î¢î¤ x -ô¢ à÷¢÷ ñî¤ð¢¹ ªðó¤òî£ Üô¢ô¶ Y -ô¢ à÷¢÷ ñî¤ð¢¹ ªðó¤òî£ âù¢Á èí¢´ ð¤®è¢°ñ¢ ªð£¼ì¢´ ¹«ó£è¤ó£ñ¢ â¿î¤ò¤¼è¢è¤ù¢«ø£ñ¢. ºîô¤ô¢ if condition -ù¤ô¢ x Ýù¶ y -ò¤¬ù õ¤ì ªðó¤òî£ âù¢ðî¬ùê¢ êó¤ ð£ó¢è¢è¤ù¢«ø£ñ¢. Üõ¢õ£Á Þ¼ð¢ð¤ù¢ Üï¢î condition -ù¤ù¢ à÷¢«÷ à÷¢÷ ð°î¤ò£ù¶ Þò颰è¤ù¢ø¶. Üîø¢° 覫ö ªè£´è¢èð¢ð좴÷¢÷ else ð°î¤è÷¢ «õ¬ô ªêò¢ò£¶. æ¼ «õ¬ô ºîô¤ô¢ ªè£´è¢èð¢ðì¢ì condition ªð£¼ï¢îõ¤ô¢¬ô âù¤ô¢ else ð°î¤ î£ù£è Þò颰è¤ù¢ø¶. Þ颰 else -ù¤ô¢ ñø¢Áªñ£Á if condition Þ¼è¢è¤ù¢ø¶. Üî¤ô¢ y Ýù¶ x -¬ù õ¤ì ªðó¤òî£ âù¢ðî¬ù check Java-3
- 18. 18 ªêò¢õîø¢°ø¤ò condition ªè£´è¢èð¢ð좮¼è¤ù¢ø¶. Þ¶ ªð£¼ï¢î¤ò¤¼ð¢ð¤ù¢ Üî¤ô¢ ªè£´è¢èð¢ðì¢ì èì¢ì¬÷è÷¢ Þò颰ñ¢. Þô¢¬ôªòù¤ô¢ 覫ö à÷¢÷ else ð°î¤ò£ù¶ Þò颰è¤ù¢ø¶. °ø¤ð¢¹:°ø¤ð¢¹:°ø¤ð¢¹:°ø¤ð¢¹:°ø¤ð¢¹: if condition -è÷¤ô¢ else Ýù¶ èì¢ì£òñ¢ ðòù¢ð´î¢î «õí¢´ñ¢ âù¢ð¶ Þô¢¬ô. if «õ¬ô ªêò¢òõ¤ô¢¬ô âù¤ô¢ else ð°î¤ Þ¼ð¢ð¤ù¢ ܶ î£ù£è «õ¬ôªêò¢»ñ¢. Listing 1.4 class pro1_4 { public static void main(String arg[]) { int rollno, tamil, english, maths, science, social, total; String sname; float avg; rollno=1; sname=”Reena”; tamil=65; english=80; maths=50; science=90; social=75; total=tamil+english+maths+science+social; avg=total/5; System.out.println(“Roll Number : “ + rollno); System.out.println(“Student Name : “ + sname); System.out.println(“Tamil : “ + tamil); System.out.println(“English : “ + english); System.out.println(“Maths : “ + maths); System.out.println(“Science : “ + science); System.out.println(“Social : “ + social); System.out.println(“Total : “ + total); System.out.println(“Average : “ + avg);
- 19. 19 if (tamil>=40 && english>=40 && maths>=40 && science>=40 && social>=40) { System.out.println(“Result : Pass”); } else { System.out.println(“Result : Fail”); } } } Þï¢î𢠹«ó£è¤ó£ñ¤ô¢ ï£ñ¢ Student - ®Â¬ìò ñ£ó¢è¢°è¬÷ð¢ ðî¤ï¢¶ Üõó¢ ܬùð¢ ð£ìé¢è÷¤½ñ¢ 40 ñî¤ð¢ªðù¢è÷¢ Üô¢ô¶ Üîø¢° Üî¤èñ£è𢠪ðø¢Á «îó¢ê¢ê¤ò¬ìï¢î¤¼è¢è¤ù¢ø£ó£ âù¢ðî¬ù Üø¤ï¢¶ ªè£÷¢Àñ¢ ð®è¢° â¿î¤ò¤¼è¢è¤ù¢«ø£ñ¢. Þ颰 && âù¢ø AND Operator, if condition -è÷¤ô¢ ðòù¢ ð´î¢îð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. For Loop C ªñ£ö¤ò¤ô¢ Þ¼ð¢ð¶ «ð£ù¢«ø Java -õ¤½ñ¢ for, while, do while Ýè¤ò loop èì¢ì¬÷è÷¢ Þ¼è¢è¤ù¢øù. for loop -¬ùè¢ ªè£í¢´ °ø¤ð¢ð¤ì¢ì îì¬õè÷¤ô¢ å«ó èì¢ì¬÷î¢ ªî£°ð¢¹è¬÷ Þòè¢è¤è¢ ªè£÷¢÷ º®»ñ¢. for (initialization; condition; increment/decrement) { ..... } for Loop Ýù¶ Íù¢Á ð¤ó¤¾è÷£èð¢ ð¤ó¤è¢èð¢ð좮¼è¢è¤ù¢ø¶. ºîô¤ô¢ intialization ð°î¤ Þ¼è¢è¤ù¢ø¶. Þî¤ô¢ ï£ñ¢ ïñ¶ variable -è÷¤ô¢ å¼ ñî¤ð¢ð¤¬ùð¢ ðî¤ò «õí¢´ñ¢. ܴ condition ð°î¤ò¤ô¢ ïñ袰 «õí¢®òð® condition -è¬÷ õ¬óò¼î¢¶è¢ ªè£÷¢÷ «õí¢´ñ¢. ܴ increment / decrement ð°î¤ò¤ô¢ ïñ¶ condition -è÷¢ 郎ø«õÁñ¢ õ¬èò¤ô¢ ñî¤ð¢¹è÷¢ õ¼ñ¢ð®è¢° statement -è¬÷ ܬñè¢è «õí¢´ñ¢. Listing 1.5 class pro1_5
- 20. 20 { public static void main(String arg[]) { int x; for (x=1; x<=100; x++) { System.out.println(x); } } } Þï¢î ¹«ó£è¤ó£ñ¤ô¢ ï£ñ¢ 1 -ô¤¼ï¢¶ 100 õ¬ó âù¢è¬÷ Display ªêò¢õîø¢°ø¤ò for loop -¬ù Þòø¢ø¤ò¤¼è¢è¤ù¢«ø£ñ¢. Þ颰 ºîô¤ô¢ x âù¢Âñ¢ variable -ô¢ 1 âù¢ø ñî¤ð¢ð¤¬ù intialize ªêò¢è¤ù¢«ø£ñ¢. ܴ condition -ù¤ô¢ x<=100 âù¢Á ªè£´î¢î¤¼è¢è¤ù¢«ø£ñ¢. Þîù¢ð® x -ô¢ 100 Üô¢ô¶ Üîø¢° °¬øõ£ù ñî¤ð¢¹è÷¢ õ¬ó Þ¼è¢èô£ñ¢. 100 -袰 «ñø¢ð¢ðì¢ì ñî¤ð¢¹è÷¢ õ¼ñ¢ªð£¿¶ loop -¬ù õ¤ì¢´ ªõ÷¤«ò õ õ¤ì «õí¢´ñ¢ âù¢Á ªð£¼÷¢. increment ð°î¤ò¤ô¢ x++ âù¢Á ªè£´è¢èð¢ð¢ì®¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þîù¢ð® x -ô¢ îø¢ªð£¿¶ ޼袰ñ ñî¤ð¢«ð£´ 1 âù¢ø ðî¤ð¢ð¤¬ù Ãì¢®è¢ ªè£÷¢÷ «õí¢´ñ¢ âù¢Á ªð£¼÷¢. loop Ýù¶ åõ¢ªõ£Á º¬ø»ñ¢ condition-ù¤¬ù êó¤ð£ó¢î¢¶ õ¤ì¢´ ÜîÂ÷¢ ªè£´è¢èð¢ð좮¼è¢°ñ¢ èì¢ì¬ùè¬÷ Þò袰è¤ù¢ø¶. ð¤ù¢ùó¢ condition ð°î¤ Þò颰è¤ù¢ø¶. Þ¶ «ð£ù¢Á ñ¦í¢´ñ¢ ñ¦í¢´ñ¢ loop -ù¢ à÷¢ Þ¼è¢è¤ù¢ø îèõô¢è÷¢ Þò颰è¤ù¢øù. while loop while loop Ýù¶ ªõ¼ñ¢ condition -ù¤¬ù ñ좴«ñ ªè£í¢´÷¢÷¶. for loop -ä «ð£ô intialization ñø¢Áñ¢ increment ð°î¤è÷¢ Þ颰 èì¢ì¬÷ò¤Â÷¢ Þô¢¬ô. Ýù£ô¢ ï£ñ¢ Üõø¢¬ø èì¢ì£òñ£è «õÁ Þìé¢è÷¤ô¢ ðòù¢ð´î¢î «õí¢´ñ¢. while (condition) { statements... } Listing 1.6 class pro1_6
- 21. 21 { public static void main(String arg[]) { int x; x=1; while (x!=100) { System.out.println(x); x++; } } } Þ颰 x âù¢ø variable à¼õ£è¢èð¢ð좮¼è¢è¤ù¢ø¶. while loop Ýóñ¢ð¤ð¢ðîø¢° ºù¢«ù x=1; âù¢Á intialize ªêò¢òð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. while loop -ù¢ à÷¢ x!=100 âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¬î»ñ¢ èõù¤»é¢è÷¢. Þîù¢ð® x -ô¢ 100 -¬ù îõ¤ø «õÁ âï¢î ñî¤ð¢¹è÷¢ Þ¼ï¢î£½ñ¢ loop -ù¢ à÷¢ ªêô¢ôô£ñ¢ âù¢Á ªð£¼÷¢. x++ âù¢ø increment statement loop -ù¢ à÷¢ Þ¼ð¢ðî¬ùè¢ èõù¤»é¢è÷¢. do while loop Þ¶¾ñ¢ while loop -¬ù𢠫ð£ô«õ Þò颰è¤ù¢ø¶. Ýù£ô¢ while loop Ýù¶ ºîô¤ô¢ condition -ù¤¬ù check ªêò¢¶õ¤ì¢´ ð¤ù¢ èì¢ì¬÷è¬÷ Þò袰è¤ù¢ø¶. Ýù£ô¢ do while loop Ýù¶ ºîô¤ô¢ èì¢ì¬÷è¬÷ Þòè¢è¤õ¤ì¢´ ð¤ù¢ùó¢ condition -ù¤¬ù check ªêò¢»ñ¢. do { Statement.... }while(condition); Listing 1.7 class pro1_7 { public static void main(String arg[]) {
- 22. 22 int x; x=1; do { System.out.println(x); x++; }while (x!=100); } } Þ颰 ºîô¤ô¢ do -õ¤¬ù ܴ Þ¼è¢è¤ù¢ø èì¢ì¬÷è÷¢ Þò颰ñ¢ ð¤ù¢ùó¢ î£ù¢ while -ô¢ Þ¼è¢è¤ù¢ø condition êó¤ð£ó¢èè¢ð¢ð´ñ¢. Þï¢î õ¬èò¤ô¢ å«ó å¼ îì¬õò£õ¶ do while loop -ù¢ à÷¢ à÷¢÷ èì¢ì¬÷è÷¢ Þòé¢è¤õ¤´ñ¢ ù¢ðî¬ù 郎ùõ¤ô¢ ªè£÷¢è.
- 23. 23 Üî¢î¤ò£òñ¢Üî¢î¤ò£òñ¢Üî¢î¤ò£òñ¢Üî¢î¤ò£òñ¢Üî¢î¤ò£òñ¢ 2. Object-Oriented Programming Object-Oriented Programming (OOP) âù¢ð¶ îø¢ªð£¿¶ ¹öè¢èî¢î¤ô¢ à÷¢÷ ñ¤èê¢ê¤øï¢î ¹«ó£è¤ó£ñ¤é¢ º¬øò£°ñ¢. Java õ£ù¶ Þï¢î º¬øò¤¬ùð¢ ð¤ù¢ðø¢ø¤î¢ î£ù¢ Þò颰è¤ù¢ø¶. âù«õ ºîô¤ô¢ Object-Oriented Programming âÂñ¢ º¬øò¤¬ù»ñ¢ Üîù¢ ðòù¢ð£´è¬÷»ñ¢ ñ¤èî¢ ªî÷¤õ£è Üø¤ï¢¶ ªîó¤ï¢¶ ªè£í¢ì£ô¢ ñ좴«ñ Java -õ¤ù¤ô¢ ïñ¢ñ£ô¢ ¹«ó£è¤ó£ñ¢è¬÷ â¿î¤è¢ªè£÷¢÷ Þò½ñ¢. å¼ °ø¤ð¢ð¤ì¢ì «õ¬ôò¤¬ùê¢ ªêò¢õîø¢è¢è£è å¼ ¹«ó£è¤ó£ñ¢ â¿î «õí¢´ñ¢ âù¢Á ¬õî¢¶è¢ ªè£÷¢Àé¢è÷¢. Üî¬ù OOP º¬øò¤ô¢ å¼ Class Ýè â¿î «õí¢´ñ¢. class âù¢ð¶ variable -è¬÷»ñ¢, function -è¬÷»ñ¢ ªè£í¢ì ªî£°ð¢¹ Ý°ñ¢. â´î¢¶è¢è£ì¢ì£è ¹î¢îèé¢è¬÷ð¢ ðø¢ø¤ò îèõô¢è¬÷ ¬èò£÷¢õîø¢è£è å¼ ¹«ó£è¤ó£ñ¢ ⿶è¤ù¢«ø£ñ¢ âù¢Á ¬õî¢¶è ªè£÷¢Àé¢è÷¢. Üîø¢ªèù¢Á å¼ class â¿î «õí¢´ñ¢. Üï¢î class -ø¢è¢° ï£ñ¢ Book âù¢Á ªðòó¢ ªè£´è¢èô£ñ¢. Þï¢î Book âÂñ¢ class -Â÷¢ ï£ñ¢ ðî¤ï¢¶ ¬õî¢¶è¢ ªè£÷¢÷ «õí¢®ò îèõô¢èÀè¢è£è variable -è¬÷ à¼õ£è¢è «õí¢´ñ¢. BookName, AuthorName, Publisher, Price ºîô¤ò îèõô¢è÷¢ Book Class -ø¢° «î¬õªòù¤ô¢ ï£ñ¢ variable -è¬÷ ÜîÂ÷¢ à¼õ£è¢èô£ñ¢. Þî¢î¬èò variable -è¬÷ data members âù¢Á ܬöè¢è¤ù¢ø«ø£ñ¢. Þõ¢õ£Á å¼ class -ù¢ à÷¢ à¼õ£è¢èð¢ðì¢ì data member è¬÷ê¢ ê£ó¢ï¢«î£ Üô¢ô¶ ê£óñ«ô£ ï£ñ¢ ðô function -è¬÷ class -è÷¤ù¢ à÷¢ â¿î¤è¢ ªè£÷¢÷ô£ñ¢. Þõ¢õ£Á class -ù¢ à÷¢ â¿îð¢ð´ñ¢ function -è¬÷ Method âù¢Á ܬöè¢è¤ù¢«ø£ñ¢. Ýè data members(variable) ñø¢Áñ¢ methods (function) Ýè¤òõø¢¬øè¢ ªè£í¢´ °ø¤ð¢ð¤ì¢ì å¼ «õ¬ôè¢è£è â¿îð¢ð´ñ¢ ¹«ó£è¤ó£ñ¢ º¬ø«ò class Ý°ñ¢. àé¢èÀ袰 ‘C’ ªñ£ö¤ò¤ô¢ ¹«ó£è¤ó£ñ¢ â¿î ªîó¤ï¢î¤¼è¢°«ñò£ù£ô¢ Struct âù¢ø¬öè¢èð¢ð´ñ¢ structure -è¬÷ð¢ ðòù¢ð´î¢î¤ò¤¼ð¢ð¦ó¢è÷¢. Üî¤ô¢ ï£ñ¢ ªõ¼ñ¢ variable -è¬÷ ñ좴ñ¢ ªè£í¢´ å¼ structure -ø¤¬ù à¼õ£è¢è¤ îèõô¢è¬÷ ê¤øð¢ð£è ðòù¢ð´î¢¶è¤ù¢«ø£ñ¢. Üî¢î¬èò Structure -è÷¤ù¢ advanced version Ýè«õ class -è÷¢ ðòù¢ð´è¤ù¢øù.
- 24. 24 å¼ º¬ø å¼ class â¿îð¢ð좴 õ¤ì¢ì£ô¢ Üî¬ùð¢ ðòù¢ð´î¢î¤ ïñ¢ñ£ô¢ Object -´è¬÷ à¼õ£è¢è¤è¢ ªè£÷¢÷ Þò½ñ¢. ²¼è¢èñ£è Ãø¤ù£ô¢ class Ýù¶ å¼ user defined data type Ýèð¢ðòù¢ð´è¤ù¢ø¶. Üî£õ¶ int, char, float, double ºîô¤ò data type -è¬÷ð¢ ðòù¢ð´î¢î¤ âõ¢õ£Á ï£ñ¢ variable -è¬÷ à¼õ£è¢è¤ ðòù¢ð´î¢¶è¤ù¢«ø£«ñ£ ܶ «ð£ô ï£ñ¢ ⿶ñ¢ class -è÷¢ data type -è÷£è Þò颰è¤ù¢øù. Üõø¢¬øè¢ ªè£í¢´ ïñ¢ñ£ô¢ variable -è¬÷ à¼õ£è¢è¤è¢ ªè£÷¢÷ Þò½ñ¢. Üî¢î¬èò variable -è¬÷«ò ï£ñ¢ Object - âù¢Á ܬöè¢è¤ù¢«ø£ñ¢. Þõ¢õ£Á class -è¬÷ à¼õ£è¢è¤ Üîù¢Íôñ¢ Object -´è¬÷ à¼õ£è¢è¤ ðòù¢ð´î¢¶ñ¢ º¬øò¤¬ùî¢î£ù¢ Object-Oriented Programming âù¢Á ܬöè¢è¤ù¢«ø£ñ¢. Listing 2.1. class book { String bookname; String authorname; String publisher; int price; public void store(String tbookname, String tauthorname, String tpublisher, int tprice) { bookname=tbookname; authorname=tauthorname; publisher=tpublisher; price=tprice; } public void display() { System.out.println(“Book Name : “ + bookname); System.out.println(“Author Name : “ + authorname); System.out.println(“Publisher : “ + publisher); System.out.println(“Price : “ + price); System.out.println(“—————————————————”); }
- 25. 25 public static void main(String arg[]) { book java = new book(); book oracle = new book(); java.store(“Java Language”,”Packianathan”, ”AnuRagham”,250); oracle.store(“Oracle Datbase”,”Packianathan”, ”AnuRagham”,125); java.display(); oracle.display(); } } Þï¢î𢠹«ó£è¤ó£ñ¤ô¢ Book âù¢ªø£¼ class â¿îð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þ颰 main( ) Function ù¤¬ùî¢ îõ¤ó¢î¢¶ Üîø¢° ºù¢ ðô õó¤è÷¢ Þ¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Üõø¢ø¤ô¢ ºîô¤ô¢ BookName, AuthorName, Publisher, Price Ýè¤ò variable -è÷¢ à¼õ£è¢èð¢ð좮¼è¢è¤ù¢øù. ܬõ Þï¢îè¢ class-ù¢ data member -è÷¢. Üî¬ùî¢ ªî£ìó¢ï¢¶ Store ñø¢Áñ¢ display âù¢Á Þóí¢´ function -è÷¢ Þ¼è¢è¤ù¢øù. Þ¬õ Methods âù¢Á ܬöè¢èð¢ð´è¤ù¢øù. Þõø¢ø¤ô¢ store function Ýù¶ parameter -è÷¤ù¢ õö¤ò£è ñî¤ð¢¹è¬÷𢠪ðø¢Á Üõø¢¬ø data member -è÷¤ô¢ ðî¤ï¢¶ ¬õð¢ðîø¢°ð¢ ðòù¢ð´è¤ù¢ø¶. ܶ«ð£ô¢ display function Ýù¶ data member -è÷¤ô¢ à÷¢÷ ñî¤ð¢¹è¬÷ Display ªêò¢¶ð¢ ð£ó¢ð¢¢ðîø¢°ð¢ ðòù¢ð´è¤ù¢ø¶. Þï¢î𢠹«ó£è¤ó£ñ¤¬ù Compile ªêò¢¶ Þò袰ñ¢ªð£¿¶ main( ) function ù¤ô¢ ޼ î£ù¢ ¹«ó£è¤ó£ñ¢ Þòé¢è Ýóñ¢ð¤è¢°ñ¢. ÞîÂ÷¢ Book java = new Book ( ) ; Book oracle = new Book ( ) ; âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þ¶«õ å¼ class -ô¤¼ï¢¶ Object-´è¬÷ à¼õ£è¢°ñ¢ º¬ø. ºîô¤ô¢ class -ù¢ ªðòó¤¬ùê¢ Ãø¤, ð¤ù¢ùó¢ à¼õ£è¢°è¤ù¢ø Object -®ù¢ ªðòó¤¬ùê¢ ªê£ô¢ô «õí¢´ñ¢. Þ颰 java ñø¢Áñ¢ oracle âù¢ðù Book Class -ô¤¼ï¢¶ à¼õ£è¢èð¢ð´ñ¢ Object -´è÷¢ Ý°ñ¢. ܴ ï£ñ¢ = âÂñ¢ assignment operator -ø¤¬ùè¢ ªè£´î¢¶ Üî¬ùî¢ ªî£ì Java-4
- 26. 26 new Book( ) âù¢Á ªè£´î¢î¤¼è¢è¤ù¢«ø£ñ¢. Þõ¢õ£Á ªè£´è¢°ñ¢ ªð£¿¶ î£ù¢ àí¢¬ñò¤ô¢ Class ù¢ Object -Ýù¶ ¹î¤î£è à¼õ£è¤ù¢ø¶. Þõ¢õ£Á Object Ýù¶ à¼õ£°ñ¢ ªð£¿¶ Üï¢î Class -ù¢ à÷¢ ï£ñ¢ õ¬óò¼î¢î¤¼è¢è¤ù¢ø data member -èÀñ¢ ñø¢Áñ¢ method -èÀñ¢ Üï¢îï¢î Object- ´èÀ袪èù¢Á îù¤î¢îù¤ò£è à¼õ£è¤ù¢øù. Üî£õ¶ Þ颰 java âù¢ø Object-ø¢è¢° âù¢Á îù¤ò£è Book Name, Author Name, Publisher, Price ºîô¤ò Variable èÀñ¢ store( ) ñø¢Áñ¢ display( ) Ýè¤ò function -èÀñ¢ à¼õ£è¤ù¢øù. Þ«î«ð£ù¢Á îù¤ò£è Oracle Object -ø¢è¢°ñ¢ à¼õ£°ñ¢. Þ¶ «ð£ô¢ âî¢î¬ù Object ´è÷¢ à¼õ£è¢°è¤ù¢ø«ø£«ñ£ Üî¢î¬ù袰ñ¢ îù¤î¢îù¤ò£è datamember -è÷¢ ñø¢Áñ¢ method -è÷¢ Þ¼ð¢ðî£è 郎ùõ¤ô¢ ªè£÷¢Àé¢è÷¢. «ñ½ñ¢ ¹«ó£è¤ó£ñ¤¬ù ï¦é¢è÷¢ àø¢Áð¢ ð£ó¢¬èò¤ô¢ java.store(‘Java Language’,‘Packia Nathan’,‘Anuragham’, 150); oracle.store(‘Oracle Database’,‘Packia Nathan’,’Anuragham’, 125) ; âù¢Á Þ¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Üî£õ¶ java âù¢ø Object -®ô¢ à÷¢÷ store function -ù¤¬ù»ñ¢ ܶ«ð£ô oracle âù¢ø object -ô¢ à÷¢÷ store function- ù¤¬ù»ñ¢ ðòù¢ð´î¢î¤ Üï¢îï¢î Object -´è÷¤ô¢ à÷¢÷ data member -è÷¤ô¢ îèõô¢è¬÷ð¢ ðî¤ï¢¶ ªè£÷¢è¤ù¢«ø£ñ¢. Þ颰 Object ªðòó¤ø¢è¢°ñ¢ function -ù¤ù¢ ªðòó¤ø¢è¢°ñ¢ ï´õ¤ô¢ å¼ ¹÷¢÷¤ Þ¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Üî£õ¶ Þï¢î Object -®ô¢ Þ¼è¢è¤ù¢ø function âù¢Á °ø¤ð¢ðîø¢è¢è£è Þõ¢õ£Á ªè£´è¢èð¢ð´è¤ù¢ø¶. «ñ½ñ¢ Þ«î º¬øò¤¬ùð¢ ðòù¢ð´î¢î¤ java.display( ) oracle.display( ) âù¢Á display function è¬÷ Þòè¢è¤ Üï¢îï¢î Object -´è÷¤ô¢ ðî¤ï¢¶ ¬õ Þ¼è¢è¤ù¢ø ñî¤ð¢¹è¬÷ display ªêò¢¶ ð£ó¢î¢¶è¢ ªè£÷¢Àè¤ù¢«ø£ñ¢. Listing 2.2 class emp { int empno,salary; String ename,job; public void assign(int tempno, String tename, String tjob, int tsalary)
- 27. 27 { empno=tempno; ename=tename; job=tjob; salary=tsalary; } public void view() { System.out.println(“Employee Number : “ + empno); System.out.println(“Employee Name : “ + ename); System.out.println(“Job : “ + job); System.out.println(“Salary : “ + salary); } } class tata { public static void main(String arg[]) { emp nancy = new emp(); emp john = new emp(); nancy.assign(101,”Nancy Jenifer”,”Analyst”,6000); john.assign(102,”John Thomas”,”Programmer”,6000); nancy.view(); john.view(); } } Þï¢î𢠹«ó£è¤ó£ñ¤ô¢ emp âù¢ø class åù¢Áñ¢ Tata âù¢ø class åù¢Áñ¢ â¿îð¢ð좮¼è¢è¤ù¢øù. Þï¢î Þóí¢´ class -ø¢è¢°ñ¢ Þ¬ìò¤ô¢ âï¢îªõ£¼ ªî£ìó¢¹ñ¢ Þô¢¬ô. emp âÂñ¢ class -ô¢ å¼ èñ¢ªðù¤ò¤ô¢ «õ¬ôð¢ ð£ó¢è¢è¤ù¢ø ªî£ö¤ô£÷ó¢ è÷¤ù¢ îèõô¢è¬÷è¢ ¬èò£÷¢õîø¢°ø¤ò ¹«ó£è¤ó£ñ¤¬ù â¿î¤ò¤¼è¢è¤ù¢«ø£ñ¢.
- 28. 28 Üî£õ¶ Þî¤ô¢ empno, ename, job, salary âù¢ø îèõô¢è¬÷ê¢ «êèó¤è¢°ñ¢ ªð£¼ì¢´ variable -è¬÷ à¼õ£è¢è¤, Üõø¢ø¤ô¢ ñî¤ð¢¹è¬÷ ðî¤õîø¢°ñ¢, ñø¢Áñ¢ Üõø¢ø¤ô¢ Þ¼è¢è¤ù¢ø ñî¤ð¢¹è¬÷ è£í¢ðîø¢è¢°ñ£è º¬ø«ò assign ñø¢Áñ¢ view Ýè¤ò function -è¬÷ â¿î¤ò¤¼è¢è¤ù¢«ø£ñ¢. Tata âù¢ªø£¼ class Þ¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þ¶ Tata âù¢Âñ¢ èñ¢ªðù¤ò¤ù¢ îèõô¢è¬÷ ðó£ñó¤è¢°ñ¢ class âù¢Á èø¢ð¬ù ªêò¢¶ ªè£÷¢Àé¢è÷¢. Þï¢î Class -ô¢ î£ù¢ main function Ýù¶ Þ¼è¢è¤ù¢ø¶ âù¢ðî¬ù»ñ¢ èõù¤»é¢è÷¢. Þï¢î ¹«óè¤ó£ññ¤¬ù ï¦é¢è÷¢ Compile ªêò¢¶ Run ªêò¢»ñ¢ ªð£¿¶ Tata èñ¢ªðù¤ò¤ô¢ à÷¢÷ main function î£ù¢ Þò颰ñ¢ âù¢ð¶ àé¢èÀ袰 郎ùõ¤¼è¢°ñ¢. Þï¢î main function -ô¢ ï£ñ¢ emp âù¢Âñ¢ class õ¤¬ùê¢ ê£ó¢ï¢î Þóí¢´ object -´è¬÷ à¼õ£è¢è¤ò¤¼è¢è¤ù¢«ø£ñ¢. Üî£õ¶, emp nancy = new emp( ) ; emp john = new emp( ) ; ºîô¤ò õó¤è¬÷ °ø¤ð¢ð¤´è¤ù¢«ø£ñ¢. ï£ñ¢ Þ¼ð¢ð«î£ Tata âù¢Âñ¢ Class- ø¢è°÷¢ Üé¢è¤¼ï¢¶ «õªø£¼ class -Ýù emp -ò¤ù¢ Object -´è¬÷ Þ颰 à¼õ£è¢è¤è¢ ªè£÷¢Àè¤ù¢«ø£ñ¢. ð¤ù¢ùó¢ nancy ñø¢Áñ¢ john Ýè¤ò Object- ´èÀ袰ø¤ò assign ñø¢Áñ¢ view function -è¬÷ð¢ ðòù¢ð´î¢î¤è¢ ªè£÷¢Àè¤ù¢«ø£ñ¢. Þõø¢ø¤ô¤¼ï¢¶ å¼ class â¿îð¢ð좴õ¤ì¢ì£ô¢ Üîù¢ Object -´è¬÷ «õÁ âï¢î class -ù¢ à÷¢ ޼ñ¢ ðòù¢ð´î¢î¤è¢ ªè£÷¢÷ô£ñ¢ âù¢ðî¬ù ªî÷¤õ£è Üø¤ï¢¶ ªè£÷¢Àé¢è÷¢. Þð¢ªð£¿¶, class âù¢ø£ô¢ âù¢ù âù¢Á åó÷¾ ªî÷¤ï¢î¤¼ð¢ð¦ó¢è÷¢. Þù¤ class ù¤¬ùð¢ ðø¢ø¤ò ªî÷¤õ£ù Syntax -ä ð£ó¢ð¢«ð£ñ¢. Syntex: [modifiers] class <class name> [extend <superclass>] [implements <interfaces>] âð¢ªð£¿¶«ñ èì¢ì¬÷è÷¤ù¢ Syntax -è¬÷ ð®è¢°ñ¢ ªð£¿¶ [ ] brackets- è÷¤ù¢ à÷¢ Þ¼ð¢ð¬õ Option -è÷¢ Ý°ñ¢. Üî£õ¶ Üõø¢¬øð¢ ðòù¢ð´î¢îô£ñ¢ Üô¢ô¶ ðòù¢ð´î¢î£ñ½ñ¢ Þ¼è¢èô£ñ¢. Þ¶õ¬ó ï£ñ¢ ð£ó¢î¢î â´î¢¶è¢ è£ì¢´è÷¤ô¢ [modifiers], [extend super class] ñø¢Áñ¢ [implement interface] ºîô£ù Þùé¢è÷¢ ðòù¢ð´î¢îð¢ðìõ¤ô¢¬ô. ܬõ åõ¢ªõ£ù¢Áñ¢ ªõõ¢«õÁ
- 29. 29 ðòù¢ð£´è¬÷è¢ ªè£í¢ì¬õ. âù«õ Üõø¢¬øî¢ îù¤ â´î¢¶è¢è£ì¢´è÷¢ Íôñ¢ Üø¤ï¢¶ ªè£÷¢÷ô£ñ¢. Inheritance Object Oriented Programming º¬øò¤ô¢ Þ¼è¢è¤ù¢ø ºè¢è¤òñ£ù ðòù¢ð£´è÷¤ô¢ Inheritance -ñ¢ åù¢Á. Þï¢î º¬øò¤ù¢ Íôñ¢ Þóí¢´ class- èÀè¢è¤¬ìò¤ô¢ å¼ Þ¬íð¢ð¤¬ù à¼õ£è¢°è¤ù¢«ø£ñ¢. Þîù¢ð® Þóí¢´ class -è÷¤ô¢ åù¢ø¤¬ù super class âù¾ñ¢ ñø¢ªø£ù¢ø¤¬ù subclass âù¾ñ¢ ܬöè¢è¤ù¢«ø£ñ¢. â´î¢¶è¢è£ì¢ì£è father âù¢ªø£¼ class-ñ¢ child âù¢Âñ¢ ªðòó¤ô¢ å¼ class-ñ¢ Þ¼ð¢ðî£è ¬õ袪è£÷¢«õ£ñ¢. father class -ù¢ à÷¢ father name, age, occupation ºîô£ù å¼ îîò¤¬ùð¢ðø¢ø¤ò îèõô¢è¬÷ê¢ «êèó¤î¢¶ ¬õè¢èð¢ð좮¼è¢è¤ù¢øù. child class -à÷¢ child name, age, hobbies ºîô£ù å¼ ñèù¤¬ùð¢ðø¢ø¤ò îèõô¢è÷¢ «êèó¤î¢¶ ¬õè¢èð¢ð좮¼è¢è¤ù¢øù âù¢Á ªè£÷¢Àé¢è÷¢. Þï¢î Þóí¢´ class -è÷¢ îù¤î¢îù¤ò£è õ¬óò¼è¢èð¢ ð좮¼ð¢ð¤ù¢ åù¢Áìù¢ åù¢Á ªî£ìó¢¹ Þ¼è¢è£¶ Üô¢ôõ£? Þð¢ªð£¿¶ Child class -ø¢è¢° å¼ Object -®¬ù à¼õ£è¢°è¤ù¢«ø£ñ¢ âù¢Á ¬õî¢¶è¢ ªè£÷¢Àé¢è÷¢. Üï¢î child object -ù¢ à÷¢ ïñ袰 father -ø¤¬ùð¢ îèõô¢è÷¢ õó«õí¢´ñ¢ âù¢Á õ¤¼ñ¢ð¤ù£ô¢ Üîø¢° ï£ñ¢ inheritance º¬øò¤¬ùè¢ ¬èò£÷ «õí¢´ñ¢. Þîø¢° extends âù¢Âñ¢ èì¢ì¬÷ð¢ ðòù¢ð´è¤ù¢ø¶. Listing 2.3 class father { String fname; int fage; public void assign(String tfname, int tfage) { fname=tfname; fage=tfage; } public void view() { System.out.println(“Father’s Name : “ + fname); System.out.println(“Father’s Age : “ + fage);
- 30. 30 System.out.println(“”); } } class child extends father { String cname; int cage; public void store(String tcname, int tcage) { cname=tcname; cage=tcage; } public void display() { System.out.println(“Child’s Name : “ + cname); System.out.println(“Child’s Age : “ + cage); System.out.println(“”); } } class school { public static void main(String arg[]) { child allen = new child(); allen.assign(“Sebastian Raj”,30); allen.store(“Allen Smith”,3); allen.view(); allen.display(); } }
- 31. 31 Þï¢î𢠹«ó£è¤ó£ñ¤ô¢ father âù¢Âñ¢ class Ýù¶ ºîô¤ô¢ â¿îð¢ð좮¼è¢è¤ù¢ø¶. Üî¬ùî¢ ªî£ìó¢ï¢¶ child âÂñ¢ class è¦ö¢è¢èí¢ìõ£Á õ¬óò¼è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. class child extends father { ..... } Þ颰 extends father âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¤ù¢ Íôñ¢ child class Ýù¶ father class àìù¢ Þ¬íè¢èð¢ð좮¼è¢è¤ù¢ø¶. âù«õ Þð¢ªð£¿¶ father class Ýù¶ child class ¬ìò superclass Ýè ªêòô¢ð´è¤ù¢ø¶. Üô¢ô¶ base Class âù¢Áñ¢ Ãøô£ñ¢. Þîù¢ð® ï¦é¢è÷¢ âð¢ªð£¿ªîô¢ô£ñ¢ child class -ø¢° Object -´è¬÷ à¼õ£è¢°è¤ù¢ø¦ó¢è«÷£ Üð¢ªð£¿ªîô¢ô£ñ¢ super class Ýù father -ù¢ Object åù¢Áñ¢ î£ù£è à¼õ£è¢èð¢ð좴 õ¤´ñ¢. ï£ñ¢ îù¤ò£è father class -ø¢è¢° ªèù¢Á Object -´è¬÷ à¼õ£è¢è «õí¢®òî¤ô¢¬ô. «ñ½ñ¢ Þï¢î ¹«ó£è¤ó£ñ¤ô¢ child allen = new child( ); âù¢Á ªè£´î¢¶ allen âù¢Âñ¢ ªðòó¤ô¢ child class -ù¢ Object -¬ù à¼õ£è¢è¤ ò¤¼è¢è¤ù¢«ø£ñ¢. Þ颰 allen.store(...) allen.display( ) ºîô£ù¬õ Child Class -¬ìò function -è÷¢ Ý°ñ¢. allen.assign(...) allen.view( ) ºîô£ù¬õ father class -ù¢ function -è÷ Ý°ñ¢. Þï¢î function -è÷¢ allen âù¢Âñ¢ child class -ù¢ Íôñ¢ Þò颰è¤ù¢ø¶ âù¢ðî¬ù Üø¤õîù¢Íôñ¢ Inheritance âõ¢õ£Á Þò颰è¤ù¢ø¶ âù¢ðî¬ù Üø¤ï¢¶ ªè£÷¢÷ô£ñ¢. °ø¤ð¢¹°ø¤ð¢¹°ø¤ð¢¹°ø¤ð¢¹°ø¤ð¢¹ Java -õ¤¬ù𢠪ð£¼î¢îõ¬óò¤ô¢ åõ¢ªõ£¼ °ø¤ð¢ð¤ì¢ì «õ¬ôò¤¬ùê¢ ªêò¢õîø¢°ñ¢ âù¢Á ðô¢«õÁ class -è÷¢ â¿î¤ ¬õè¢èð¢ð좴 Þ¼è¢è¤ù¢øù. Üï¢î class -è¬÷ ï£ñ¢ «î¬õ被èø¢ø£ó¢«ð£ô Object -´è÷£è à¼õ£è¢è¤ ðòù¢ð´î¢î¤è¢ ªè£÷¢÷ «õí¢´ñ¢. Üô¢ô¶ ï£ñ£è å¼ class -¬ù à¼õ£è¢è¤ Üï¢î class -ø¢° ãø¢è¢ªèù«õ Þ¼è¢è¤ù¢ø Java class -è÷¤¬ù extend èì¢ì¬÷ò¤¬ùð¢ ðòù¢ð´î¢î¤ Inheritance ªêò¢¶ñ¢ ðòù¢ð´î¢î¤è¢ ªè£÷¢÷ô£ñ¢.
- 32. 32 Constructors å¼ class -ù¢ à÷¢ Üï¢î class -ù¢ ªðòó¤«ô«ò function -è÷¤¬ù ⿶ñ¢ º¬ø«ò consturctor âù¢Á ܬöè¢èð¢ð´è¤ù¢ø¶. â´î¢¶è¢è£ì¢ì£è class circle âù¢Á å¼ class Þ¼ð¢ðî£è ªè£í¢ì£ô¢ Üï¢î class -ù¢ à÷¢ circle( ) âù¢ø ªðòó¤ô¢ å¼ function ޼袰ñ£ù£ô¢ ܶ Constructor function âù¢Á ܬöè¢èð¢ð´è¤ù¢ø¶. ê£î£óíñ£è ï£ñ¢ å¼ class -ù¢ à÷¢ ⿶ñ¢ function -è¬÷ Üï¢î class- ù¢ Object -è÷¤ù¢ õö¤ò£èî¢î£ù¢ Þò袰«õ£ñ¢. Ýù£ô¢ Constructor function è÷¤¬ù𢠪ð£¼î¢î õ¬óò¤ô¢ ï£ñ£è Üî¬ù Þòè¢èî¬õò¤ô¢¬ô. ñ£ø£è ܶ î£ù£è«õ Þò颰ñ¢. âõ¢õ£ªøù¤ô¢ âð¢ªð£¿ªîô¢ô£ñ¢ å¼ class - ù¢ Object à¼õ£è¢èð¢ð´è¤ù¢ø«î£, Üð¢ªð£¿ªîô¢ô£ñ¢ Üï¢î Class ù¢ à÷¢ Constructor Function -è÷¢ ޼袰ñ¢ ðì¢êî¢î¤ô¢ ܬõ î£ù£è ºîô¤ô¢ Þòé¢è¤õ¤´ñ¢. âù«õ Þï¢î Constructor º¬øò¤ù¢ Íôñ¢ class -ù¢ Object ´è÷¢ à¼õ£°ñ¢ êñòî¢î¤ô¢ ïìè¢è «õí¢®ò intialization ºîô¤ò ïñè¢°î¢ «î¬õò£ù «õ¬ôèÀ袰ø¤ò ¹«ó£è¤ó£ñ¢è¬÷ â¿î¤è¢ ªè£÷¢÷ô£ñ¢. Listing 2.4 class hello { hello() { System.out.println(“Hello Constructor”); } public static void main(String arg[]) { hello one = new hello(); hello two = new hello(); hello three = new hello(); } } Þï¢î ¹«ó£è¤ó£ñ¤ô¢ hello âù¢ø class â¿îð¢ð좮¼è¢è¤ù¢ø¶. «ñ½ñ¢ hello âù¢ø class-ù¢ ªðòó¤«ô«ò function åù¢Áñ¢ â¿îð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢.
- 33. 33 Þ¶ Þï¢î class -ù¢ constructor function Ý°ñ¢. ÞîÂ÷¢, System.out.println(“Hello Constructor”); âù¢ø õó¤ â¿îð¢ð좮¼è¢è¤ù¢ø¶. main( ) function -ô¢ one, two, three âù¢Á Íù¢Á Object -è÷¢ new operator -ø¤¬ùð¢ ðòù¢ð´î¢î¤ à¼õ£è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þï¢î Íù¢Á Object -è÷¢ à¼õ£°ñ¢ êñòî¢î¤½ñ¢ Üï¢îï¢î object ´è¢°ø¤ò constructor function -è÷¢ î£ù£è Þòé¢è¤õ¤´ñ¢. Listing 2.5 class circle { int x; int y; int radius; circle() { x=0; y=0; radius=0; } circle(int tx,int ty,int tradius) { x=tx; y=ty; radius=tradius; } circle(circle obj) { x=obj.x; y=obj.y; radius=obj.radius; } Java-5
- 34. 34 public void store(int tx,int ty,int tradius) { x=tx; y=ty; radius=tradius; } public void display() { System.out.println(“X value: “ + x); System.out.println(“Y value: “ + y); System.out.println(“Radius: “ + radius); System.out.println(“”); } } class check { public static void main(String arg[]) { circle one = new circle(); circle two = new circle(5,10,15); circle three = new circle(two); one.display(); two.display(); three.display(); } } Þï¢î ¹«ó£è¤ó£ñ¤ô¢ circle âù¢Á å¼ class â¿îð¢ð좮¼è¢è¤ù¢ø¶. ê£î£óíñ£è å¼ circle õ¬óò «õí¢´ñ¢ âù¢ø£ô¢ ¬ñòð¢¹÷¢÷¤»ñ¢(Centre Point) Ýóºñ¢(Radius) «î¬õ. âù«õ ï£ñ¢ x, y ñø¢Áñ¢ radius âù¢Á Íù¢Á variable -è¬÷ class-ù¢ à÷¢ â¿î¤ò¤¼è¢è¤ù¢«ø£ñ¢. circle âù¢ø ªðòó¤ô¢ Íù¢Á Constructor function -è÷¢ â¿îð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. ºîô¢ circle constructor function -ù¤ô¢ âï¢î å¼ ñî¤ð¢¹èÀñ¢ argument -è÷£è
- 35. 35 ªè£´è¢èð¢ð좮¼è¢è õ¤ô¢¬ô. Þóí¢ì£õ¶ constructor function -ù¤ô¢ tx, ty, tradius âù¢Á Íù¢Á int variable è÷¢argument -è÷£è õ£é¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Íù¢ø£õ¶, circle constructor function -ù¤ô¢ Obj âù¢Âñ¢ circle class -ù¢ variable, argument Ýè ªè£´è¢èð¢ððð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þï¢î Íù¢Á constructor function è÷¤ô¢ ãî£õ¶ åù¢Á, ï£ñ¢ Üï¢î class -ø¢è¢° Object -è¬÷ à¼õ£è¢°ñ¢ ªð£¿¶ ªè£´è¢è¤ù¢ø ñî¤ð¢¹èÀ袰 ãø¢ø£ø¢ð¢ «ð£ô Þò颰è¤ù¢ø¶. main ( ) function ù¤ô¢, circle one = new circle( ); âù¢Á ªè£´è¢°ñ¢ ªð£¿¶ ï£ñ¢ ºîô¤ô¢ â¿î¤ò¤¼è¢è¤ù¢ø constructor function Þò颰è¤ù¢ø¶. ܴ circle two=new circle(5, 10, 15); âù¢Á ªè£´è¢°ñ¢ªð£¿¶ Þóí¢ì£õî£è ï£ñ¢ â¿î¤ò¤¼è¢è¤ù¢ø constructor function Ýù¶ Þò颰è¤ù¢ø¶. ãªùù¤ô¢ ï£ñ¢ Object -®¬ù à¼õ£è¢°ñ¢ ªð£¿¶ Íù¢Á int ñî¤ð¢¹è¬÷ ªè£´î¢î¤¼è¢è¤ù¢«ø£ñ¢. Üõø¢¬ø ªðø¢Áè¢ ªè£÷¢õîø¢° õêî¤ò£è Þóí¢ì£õ¶ constructor function Þ¼ð¢ðî£ô¢ Üï¢î function Þò颰è¤ù¢ø¶.ܴ ï£ñ¢ circle three = new circle (two); âù¢Á ªè£´è¢°ñ¢ ªð£¿¶ ï£ñ¢ â¿î¤ò¤¼è¢è¤ù¢ø Íù¢ø£õ¶ constructor function Þò颰è¤ù¢ø¶. ãªùù¤ô¢ îø¢ªð£¿¶ three âÂñ¢ ï£ñ¢ ¹î¤ò Object -®¬ù à¼õ£è¢°ñ¢ ªð£¿¶ ãø¢è¢ªèù«õ Þ¼è¢è¤ù¢ø Object åù¢ø¤ô¢ Þ¼è¢è¤ù¢ø ñî¤ð¢¹è¬÷ Üð¢ð®«ò Þð¢ªð£¿¶ ï£ñ¢ à¼õ£è¢°ñ¢ Object -®ø¢è¢°÷¢ õó «õí¢´ñ¢ âù¢ðîø¢è£è two âù¢ø Object-®¬ù parameter Ýè ÜÂ𢹠è¤ù¢«ø£ñ¢. circle class -ù¢ object -®¬ù«ò parameter Ýè õ£é¢è¤è¢ªè£÷¢õîø¢° õêî¤ò£è Íù¢ø£õ¶ constructor function â¿îð¢ð좴ò¤¼ð¢ðî£ô¢ ܶ Þò颰è¤ù¢ø¶. ªñ£î¢îî¢î¤ô¢ constructor function è÷¢ Object -´è÷¢ à¼õ£°ñ¢ êñòî¢î¤ô¢ î£ù£è Þòé¢è¤ ï£ñ¢ ªè£´î¢î¤¼è¢è¤ù¢ø ܬù «õ¬ôè¬÷»ñ¢ ªêò¢õîø¢°ñ¢ ðòù¢ð´è¤ù¢ø¶ âù¢ðî¬ù 郎ùõ¤ô¢ ªè£÷¢Àé¢è÷¢. °ø¤ð¢¹:°ø¤ð¢¹:°ø¤ð¢¹:°ø¤ð¢¹:°ø¤ð¢¹: å«ó ªðòó¤ù¤ô¢ åù¢Á袰ñ¢ «ñø¢ð¢ðì¢ì function-è¬÷ ⿶«õ£«ñ ò£ù£ô¢ Üîø¢è¢° function overloading âù¢Á ªðòó¢. Þï¢î º¬øò¤ô¢ function- è¬÷ ⿶ñ¢ ªð£¿¶ åõ¢ªõ£Á function -ù¤½ñ¢ ªõõ¢«õÁ data type -è÷¤ô¢
- 36. 36 parameter -è÷¢ ªè£´è¢èð¢ð좮¼è¢è «õí¢´ñ¢. ï£ñ¢ function -¬ù Þò袰ñ¢ ªð£¿¶ ªè£´è¢è¤ù¢ø parameter ñî¤ð¢¹èÀ袰 ãø¢ð Üï¢îï¢î function -è÷¢ Þò颰ñ. ªêù¢ø ¹«ó£è¤ó£ñ¤ô¢ circle âù¢ø ªðòó¤ô¢ Íù¢Á function-è÷¢ â¿îð¢ð좮¼ð¢ð¶ñ¢ function overloading º¬øò¤ô¢ î£ù¢ âù¢ðî¬ù 郎ùõ¤ô¢ ªè£÷¢è. Modifiers: ªð£¶õ£è class -¬ù ⿶ñ¢ ªð£¿¶ modifiers âù¢Á ܬöè¢èð¢ð´ñ¢ abstract, public, ñø¢Áñ¢ final ºîô£ù¬õ ðòù¢ð´î¢îð¢ð´è¤ù¢øù. 覫ö ªè£´è¢èð¢ð좴÷¢÷ â´î¢¶è¢è£ì¢´è¬÷ èõù¤»é¢è÷¢ abstract class my_graphics { .... } public final class String { .... } abstract âù¢Á ªè£´è¢°ñ¢ ªð£¿¶ Üï¢î class-ù¢ à÷¢ â¿îð¢ð´ñ¢ function åù¢ªøÂñ¢ abstract Ýè Þ¼è¢è «õí¢´ñ¢. abstract class åù¢Á Þ¼ð¢ðî£è¾ñ¢ Üî¬ùê¢ ê£ó¢ï¢¶ ðô subclass -è÷¢ Þ¼ð¢ðî£è¾ñ¢ ªè£÷¢Àé¢è÷¢. â´î¢¶è¢ è£ì¢ì£è my_graphics âù¢ø class Ýù¶ abstract class Ýè Þ¼è¢è¤ù¢ø¶. Üî¬ùê¢ ê£ó¢ï¶ circle, rectangle, triangle ºîô¤ò class-è÷¢ subclass-è÷£è Þ¼è¢è¤ù¢øù. Þ¬õ ܬùî¢î¤¼è¢°ñ¢ Draw âù¢ø ªðòó¤ô¢ function-è÷¢ Þ¼è¢è¤ù¢ø¶ âù¢Á ¬õ袪è£í¢ì£ô¢, ܬõ åõ¢ªõ£ù¢Áñ¢ ªõõ¢«õÁ «õ¬ô ªêò¢õîø¢°ð¢ ðòù¢ð´ñô¢ôõ£? Þ¶ «ð£ù¢ø êñòé¢è÷¤ô¢ ï£ñ¢ Þõø¢¬ø abstract º¬øò¤ô¢ â¿î «õí¢´ñ¢. final âù¢ø modifier Ýù¶ ðòù¢ð´î¢îð¢ðì¢ì£ô¢ Üï¢î class -¬ù inheritance ªêò¢ò Þòô£¶. Üî£õ¶ Üï¢î class Ýù¶ «õÁ âï¢î class -ø¢è¢°ñ¢ superclass Ýè ªêòô¢ðì Þòô£¶. public âù¢ø modifier Ýù¶ ðòù¢ð´î¢îð¢ðì¢ì£ô¢ Üï¢î class -¬ù ,
- 37. 37 «õÁ ðô ¹«ó£è¤ó£ñ¢è÷¤ô¢ Þ¼ï¢¶è¢ ðòù¢ð´î¢î¤è¢ ªè£÷¢÷ô£ñ¢. â´î¢¶è¢è£ì¢ì£è ï£ñ¢ Java õ¤ô¢ ðòù¢ð´î¢¶ñ¢ String âù¢Âñ¢ class -¬ù public class Ýè â¿î¤ Þ¼ð¢ðîù£ô¢ î£ù¢ ïñ¢ñ£ô¢ Üî¬ù ܬù ¹«ó£è¤ó£ñ¢è÷¤½ñ¢ ðòù¢ð´î¢î º®è¤ù¢ø¶. this ñø¢Áñ¢ñø¢Áñ¢ñø¢Áñ¢ñø¢Áñ¢ñø¢Áñ¢ super Java õ¤ô¢ this ñø¢Áñ¢ super âù Þóí¢´ ê¤ø𢹠keyword -è÷¢ Þ¼è¢è¤ù¢øù. å¼ class -ù¢ à÷¢ ï£ñ¢ ðô¢«õÁ variable -è÷¢ ñø¢Áñ¢ function -è¬÷ â¿î¤ ò¤¼ð¢«ð£ñ¢. Þõø¢¬ø Üï¢î class -è÷¤ù¢ Object ´è÷¢ õö¤ò£è Þò袰è¤ù¢«ø£ñ¢ Üô¢ôõ£? Üï¢î êñòé¢è÷¤ô¢ åõ¢ªõ£Á Object -ø¢è¢°ñ¢ âù¢Á îù¤î¢îù¤ò£è variable -è÷¢ ºîô£ù¬õ à¼õ£°ñ¢. âï¢î variable âï¢î object -®Â¬ìò¶ âù¢ðî¬ù ªê£ô¢õîø¢è¢è£è this âÂñ¢ operator ðòù¢ð´è¤ù¢ø¶. Listing 2.6 class student { int rollno; String name; public void store(int rollno, String name) { this.rollno = rollno; this.name = name; } public void display() { System.out.println(“Roll Number: “ + this.rollno); System.out.println(“Name: “ + this.name); System.out.println(“”); } public static void main(String arg[]) { student nancy = new student();
- 38. 38 student john = new student(); student george = new student(); nancy.store(1,”Nancy Jenifer”); nancy.display(); john.store(2,”John Thomas”); john.display(); george.store(3,”George Clinton”); george.display(); } } Þ颰 student âù¢Âñ¢ class ô¢ õ¬óò¼è¢èð¢ð좴÷¢÷ RollNo, Name, Ýè¤ò variable -è¬÷ Üï¢î class-ù¢ function è÷¤ô¢ this.Rollno, this.name âù¢Á ðòù¢ð´î¢î¤ò¤¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Üî£õ¶ Student class -ø¢è¢°, ï£ñ¢ nancy, john, george âù¢Á Íù¢Á Object -è÷¢ à¼õ£è¢è¤ò¤¼è¢è¤ù¢«ø£ñ¢. Þï¢î Íù¢Á object -´èÀ袰ñ¢ îù¤î¢îù¤ò£è Rollno, Name ºîô£ù variable-è÷¢ Þ¼ð¢ð¬î 郎ùõ¤ô¢ ªè£÷¢Àé¢è÷¢. ï£ñ¢ nancy.store( ), john.store( ) âù¢Á õ¬èò¤ô¢ function -è¬÷ àð«ò£è¤è¢°ñ¢ ªð£¿¶, Üï¢î function -è÷¤ô¢ this.rollno, this.name âù¢Á ªè£´î¢î¤¼ð¢ðîù¢ Íôñ¢ Üï¢îï¢î object -èÀ袰ø¤ò variable -è÷¢ ðòù¢ð´î¢îð¢ð´è¤ù¢øù. °ø¤ð¢¹ :°ø¤ð¢¹ :°ø¤ð¢¹ :°ø¤ð¢¹ :°ø¤ð¢¹ : Þ颰 this âù¢ð¶ ðòù¢ð´î¢îðð¢ì£õ¤ì¢ì£½ñ¢ åù¢Áñ¢ ð¤óê¢ê¬ù Þô¢¬ô. ãªùù¤ô¢ Ü颰 Þòø¢¬èò£è«õ this operator Þ¼ð¢ðî£è Java compiler 郎ùî¢¶î¢ ªè£÷¢Àñ¢. super âù¢ð¶ inheritance ªêò¢»ñ¢ªð£¿¶ ðòù¢ð´è¤ù¢ø¶. Üî£õ¶ Child class -è÷¤ô¢ ޼ super class -ô¢ Þ¼è¢è¤ù¢ø function -è¬÷ àð«ò£èð¢ð´î¢¶õîø¢° Þ¶ ðòù¢ð´è¤ù¢ø¶. °ø¤ð¢ð£è å¼ super class ô¢ constructor function Þ¼ð¢ðî£è ªè£÷¢Àé¢è÷¢. ï£ñ¢ child class -ø¢° object - ´è¬÷ à¼õ£è¢°ñ¢ ªð£¿¶ child class -ô¢ Þ¼è¢è¤ù¢ø constructor function î£ù¢ Þò颰ñ¢. Ýù£ô¢ inheritance Þ¼ð¢ðîù£ô¢ base class -ù¢ object åù¢Á î£ù£è à¼õ£°ñ¢ function -è÷¤ø¢° ñî¤ð¢¹è¬÷ ªè£´ð¢ðîø¢° super âÂñ¢ º¬øò¤ù£ô¢ ðòù¢ð´î¢î¤è¢ ªè£÷¢÷ô£ñ¢. Listing 2.7
- 39. 39 class state { String state_name; state(String tstr) { state_name = tstr; } public void state_assign(String tstr) { state_name = tstr; } public void state_display() { System.out.println(“State Name : “ + state_name); } } class city extends state { String city_name; city(String tstr) { super(“Tamil Nadu”); city_name = tstr; } public void city_assign(String tstr) { city_name = tstr; } public void city_display()
- 40. 40 { System.out.println(“City Name : “ + city_name); } } class country { public static void main(String arg[]) { city chennai = new city(“Chennai”); chennai.state_display(); chennai.city_display(); } } Þï¢î𢠹«ó£è¤ó£ñ¤ô¢ state ñø¢Áñ¢ city âù¢Á Þóí¢´ class -è÷¢ Þ¼è¢è¤ù¢øù. Þóí¢´ñ¢ inheritance º¬øò¤ô¢ Þ¬íè¢èð¢ð좮¼è¢è¤ù¢ø¶. state âù¢ð¶ superclass Ýè¾ñ¢city âù¢ð¶childclassÝè¾ñ¢ Þ¼è¢è¤ù¢ø¶. Þóí¢´ class è÷¤½«ñ constructor function â¿îð¢ð좮¼è¢è¤ù¢ø¶. main() function-ù¤ô¢ ï£ñ¢ citychennai=newcity(‘chennai’) âù¢Á ªè£´î¢¶ chennai âù¢Á å¼ Object -¬ù city âÂñ¢ class -ô¢ ޼ à¼õ£è¢°è¤ù¢«ø£ñ¢. ï£ñ¢ parameter Ýè ªè£´è¢°ñ¢ ‘Chennai’ âù¢ø ñî¤ð¢¹ cityclass-ù¢ constructor -¼è¢° àó¤ò¶. city class -ù¢ constructor function -ù¤ô¢ ï£ñ¢ super (‘Tamil nadu’); âù¢Á ªè£´î¢î¤¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þï¢î èì¢ì¬÷ super classÝù state ¬ìò constructor function -ø¢° ñî¤ð¢¹è¬÷è¢ ªè£´è¢è¤ù¢ø¶. Package Package âù¢ð¶ ðô java ¹«ó£è¤ó£ñ¢è¬÷»ñ¢ ñø¢Áñ¢ class -è¬÷»ñ¢ ªè£í¢ì å¼ ªî£°ð¢¹ Ý°ñ¢. Üî£õ¶ å¼ º¬ø â¿îð¢ðì¢ì ¹«ó£è¤ó£ñ ¢è¬÷«ò£ Üô¢ô¶ class -è¬÷«ò£ «õí¢®ò ªð£¿¶ «î¬õð¢ðì¢ì Þìé¢è÷¤ô¢ ñ¦í¢´ñ¢ ñ¦í¢´ñ¢ ðòù¢ð´î¢î¤è¢ ªè£÷¢õîø¢è¢è£è Package º¬øð¢ ðòù¢ð´è¤ù¢ø¶. ï£ñ¢ ⿶è¤ù¢ø ðô¢«õÁ class - è¬÷ å¼ Package Ýè à¼õ£è¢è¤õ¤ì¢´ ð¤ù¢ùó¢ Üî¬ù «õí¢®ò Þìî¢î¤ô¢ ðòù¢ð´î¢î¤è¢ ªè£÷¢÷ô£ñ¢. Ü«î«ð£ô¢ java ªñ£ö¤ò¤½ñ¢ ðô¢«õÁ ðí¤è¬÷ê¢ ªêò¢õîø¢è¢è£è Ëø¢Áè¢èíè¢è£ù class -èÀñ¢ ¹«ó£è¤ó£ñ¢èÀñ¢ ðô Package -è÷£è â¿îð¢ð좴 Þ¼è¢è¤ù¢øù. åõ¢ªõ£Á Package -ñ¢ °ø¤ð¢ð¤ì¢ì ê¤ô ðòù¢ð£´è¬÷ ªè£í¢ì class -è¬÷ îù¢ùèî¢«î ªè£í¢´÷¢÷¶. Þõø¢¬ø ï£ñ¢ «õí¢®ò êñòé¢è÷¤ô¢
- 41. 41 ðòù¢ð´î¢î¤è¢ ªè£÷¢÷ «õí¢´ñ¢. ܆ìõ¬í܆ìõ¬í܆ìõ¬í܆ìõ¬í܆ìõ¬í 1.2 Standard Java Packages Api Packages Description java.applet Applet classes and interfaces java.awt Absract windowing Toolkit ( Awt) Class and interfaces. java.awt.image (sub Package of Awt) Bitmap image classes and interfaces. java.awt.peer (subpackage of Awt) Platform-specific AWT Classes and interfaces (such ads Windows, sun, and machitosh) java.io Input/Output classes and interfaces java.lang Core java language classes and interfaces. Java.net Network classes and interfaces. java.util Utility classes and interface. Sun.tool.debug Debuging classes and interface. Import å¼ Package -ô¢ à÷¢÷ class -è¬÷»ñ¢ ñø¢Áñ¢ ¹«ó£è¤ó£ñ¢è¬÷»ñ¢, ï£ñ¢ ⿶è¤ù¢ø ¹«ó£è¤ó£ñ¢è÷¢ ðòù¢ð´î¢î «õí¢´ñ¢ âù¢ø£ô¢ ºîô¤ô¢ Üï¢î Package -è¬÷ ï£ñ¢ ïñ¢º¬ìò ¹«ó£è¤ó£ñ¤ô¢ ðòù¢ð´î¢¶è¤ù¢«ø£ñ¢ âù¢Á ªê£ô¢õîø¢° import âù¢ø èì¢ì¬÷ò¤¬ùð¢ ðòù¢ð´î¢î «õí¢´ñ¢. import -èì¢ì¬÷ò¤¬ùè¢ ªè£´î¢¶ Package -ù¢ ªðòó¤¬ùè¢ ªè£´ð¢ðîù¢ Íôñ¢ å¼ Package -ô¢ à÷¢÷ ܬù class -è¬÷»ñ¢ ïñ¢º¬ìò ¹«ó£è¤ó£ñ¢è÷¤ô¢ ðòù¢ð´î¢î¤è¢ ªè£÷¢÷ Þò½ñ¢. import java.applet.*; import java.awt.* ; import java.net.URL ; «ñ£ô¢ ªè£´è¢èð¢ð좴÷¢÷ â´î¢¶è¢ è£ì¢´è÷¤ù¢ ð® ï£ñ¢ applet, awt, net ºîô¤ò Package è¬÷ import ªêò¢î¤¼è¢è¤ù¢«ø£ñ¢. Üõø¢ø¤ô¢ * âù¢Á ªè£´è¢èð¢ð좮¼ð¢ðîù¢ ªð£¼÷¢ âù¢ù ªõù¢ø£ô¢. Üï¢î Package -ô¢ à÷¢÷ ܬù class -è¬÷»ñ¢ ðòù¢ð´î¢î¤è¢ ªè£÷¢÷ô£ñ¢ âù¢ð¶ Ý°ñ¢.
- 42. 42 Üî¢î¤ò£òñ¢Üî¢î¤ò£òñ¢Üî¢î¤ò£òñ¢Üî¢î¤ò£òñ¢Üî¢î¤ò£òñ¢ 3. Applets ñø¢Áññø¢Áññø¢Áññø¢Áññø¢Áñ¢¢¢¢¢Application Þ¶ õ¬ó java -õ¤ù¢ Ü®ð¢ð¬ì ¹«ó£è¤ó£ñ¤é¢ º¬øè¬÷ ñ좴«ñ Üø¤ï¢¶ Þ¼è¢è¤ù¢«ø£ñ¢. àí¢¬ñò¤ô¢ java -õ¤¬ùð¢ ðòù¢ð´î¢î¤ Applets âù¢ø¬öè¢èð ¢ðìè¢Ã®ò web page -è÷¤ô¢ ðòù¢ð´ñ¢ ¹«ó£è¤ó£ñ¢è¬÷»ñ¢ ñø¢Áñ¢ Application âù¢ø¬öè¢èð¢ ðìè¢Ã®ò Graphical user interface (GUI) ¹«ó£è¤ó£ñ¢è¬÷»ñ¢ â¿î¤è¢ ªè£÷¢÷ô£ñ¢. Þ¬õ window operating System î¢î¤ô¢ Þò颰è¤ù¢øù. Applets âùð¢ð´ð¬õ º¿è¢è º¿è¢è web browser -è÷¤ô¢ Þò颰ñ¢. âï¢î å¼ °ø¤ð¢ð¤ì¢ì «õ¬ôò¤¬ùê¢ ªêò¢õîø¢°ñ¢ ïñ¢ñ£ô¢ Applet õ¬è ¹«ó£è¤ó£ñ¢è¬÷ â¿î¤è¢ ªè£÷¢÷ Þò½ñ¢. Þõ¢õ£Á à¼õ£è¢èð¢ð´ñ¢ Applet - è¬÷ Hyper Text Markup Language (HTML) âù¢ø¬öè¢èð¢ð´ñ¢ internet -®ô¢ ðòù¢ð´ñ¢ ªñ£ö¤ò¤ù¢ Íôñ¢ Þòè¢è «õí¢´ñ¢. Internet Explorer ñø¢Áñ¢ Netscape Navigator ºîô£ù¬õ ðóõô£è ðòù¢ð´î¢îð¢ð´ñ¢ Web Browser-è÷¢ Ý°ñ¢. Þõø¢ø¤ô¢ î£ù¢ ï£ñ¢ Web site- è¬÷ð¢ ð£ó¢è¢è¤ù¢«ø£ñ¢. Þï¢î web Browser-è÷¢ Java õ¤ô¢ â¿îð¢ð´ñ¢ Applet è¬÷ ¹ó¤ï¢¶ Þò袰ñ¢ î¤øù¢ ð¬ìî¢î¬õò£è Þ¼è¢è¤ù¢øù. ï£ñ¢ Applet ¹«ó£è¤ó£ñ¢è¬÷ â¿î¤ º®î¢î ð¤ø° Browser è÷¤ô¢ ªêù¢Á Check ªêò¢¶ ð£ó¢è¢è «õí¢´ñ¢ âù¢ð¶ Þô¢¬ô. ñ£ø£è Applet -è¬÷ Check ªêò¢¶ ð£ó¢ð¢ðîø¢è¢ªèù¢«ø appletviewer âù¢ø tool åù¢Á JDK õ¤ô¢ Þ¼è¢è¤ù¢ø¶. Þî¬ùð¢ ðòù¢ð´î¢î¤ ïñ¢ñ£ô¢ Applet è÷¢ êó¤ò£è Þò颰è¤ù¢øî£ âù¢ðî¬ù êó¤ð£ó¢î¢¶è¢ ªè£÷¢÷ Þò½ñ¢. ºîô¢ºîô¢ºîô¢ºîô¢ºîô¢ Applet ¹«ó£è¤ó£ñ¢¹«ó£è¤ó£ñ¢¹«ó£è¤ó£ñ¢¹«ó£è¤ó£ñ¢¹«ó£è¤ó£ñ¢ Listing 3.1 import java.applet.*; import java.awt.Graphics; public class helloapplet extends java.applet.Applet { public void init() { resize(200,150); }
- 43. 43 public void paint(Graphics g) { g.drawString(“Hello World!”, 50,50); } } «ñ«ô ªè£´è¢èð¢ð좴÷¢÷ ¹«ó£è¤ó£ñ¤¬ù Üð¢ð®«ò å¼ editor -ô¢ Type ªêò¢¶ ªè£÷¢Àé¢è÷¢. file-ä save ªêò¢»ñ¢ ªð£¿¶ ñøè¢è£ñô¢ HelloApplet.java âù¢ø ªðòó¤ô¢ ð ªêò¢»éè÷¢. ãªùù¤ô¢ ï£ñ¢ â¿î¤ò¤¼è¢è¤ù¢ø class Ýù¶ public class Ýè Þ¼è¢è¤ù¢ø¶. ï£ñ¢ Java ¹«óè¤ó£ñ¤ù¤ô¢ public class åù¢ø¤¬ù ⿶«õ£«ñò£ù£ô¢ Üï¢î file ô¤ø¢° ªðòó¤´ñ¢ ªð£¿¶ Üï¢î class -ù¢ ªðòó¤¬ù«ò ªè£´è¢è «õí¢´ñ¢ âù¢ðî¬ù 郎ùõ¤ô¢ ªè£÷¢Àé¢è÷¢. import java.applet.*; âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þ颰 applet âù¢ø Package - ä ï£ñ¢ import ªêò¢î¤¼è¢è¤ù¢«ø£ñ¢. Þï¢î Package-ô¢ î£ù¢ applet ¹«ó£è¤ó£ñ¢è¬÷ ⿶õîø¢°î¢ «î¬õò£ù class -è÷¢ Þ¼è¢è¤ù¢øù. «ñ½ñ¢ public class HelloworldApplet extends java.applet.Applet âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Üî£õ¶ HelloworldApplet âù¢Á ï£ñ¢ ⿶è¤ù¢ø ¹î¤ò class -ø¢è¢° java.applet.Applet âù¢Á ãø¢è¢ªèù«õ Þ¼è¢è¤ù¢ø å¼ class -àìù¢ extends èì¢ì¬÷ò¤¬ùð¢ ðòù¢ð´î¢î¤ inheritance ªêò¢òð¢ ð좮¼è¢è¤ù¢ø¶. ï¦é¢è÷¢ âð¢ªð£¿¶ Applet õ¬èò¤¬ùê¢ ê£ó¢ï¢î ¹«ó£è¤ó£ñ¢è¬÷ â¿î «õí¢®ò¤¼ï¢î£½ñ¢ Üð¢ªð£¿¶ªîô¢ô£ñ¢ «ñø¢è¢èí¢ì º¬øò¤¬ù èì¢ì£òñ£è ð¤ù¢ðø¢ø¤ò£è «õí¢´ñ¢. ãªùù¤ô¢ java.applet.Applet âù¢ø class Ýù¶ º¿è¢è º¿è¢è Applet - è¬÷ à¼õ£è¢è¤ è좴ð¢ð´î¢î¤è¢ îò ܬù ¹«ó£è¤ó£ñ¢è¬÷»ñ¢ îù¢ùèî¢«î ªè£í¢ì å¼ class ݶñ¢. ï£ñ¢ ⿶è¤ù¢ø Class -ø¢è¢° Þï¢î class àìù¢ inheritance ªêò¢»ñ¢ ªð£¿¶ ïñ¢º¬ìò class Ýù¶ å¼ Applet Class Ýè ñ£ø¤õ¤´è¤ù¢ø¶. ð¤ù¢ùó¢ ïñè¢°î¢ «î¬õò£ù ¹«ó£è¤ó£ñ¢è¬÷ ñ좴ñ¢ Þï¢î class ù¢ à÷¢ â¿î¤è¢ ªè£í¢ì£ô¢ «ð£¶ñ£ù¶. public void init( ) { ... }
- 44. 44 âù¢Á å¼ function Þ¼ð¢ðî¬ùè¢ èõù¤»é¢è÷¢. Þï¢î function ù¤¬ù Þîø¢° ºù¢ ï¦é¢è÷¢ ðòù¢ð´î¢î¤ò¤¼è¢è ñ£ì¢¯ó¢è÷¢. âð¢ªð£¿ªîô¢ô£ñ¢ ï¦é¢è÷¢ Applet ⿶è¤ù¢ø¦ó¢è«÷£ Üð¢ªð£¿ªîô¢ô£ñ¢ Þï¢î init( ) function -ù¤¬ù â¿î¤ò£è «õí¢´ñ¢. ãªùù¤ô¢ Applet ¹«ó£è¤ó£ñ¢è÷¢ init( ) function -ô¢ ޼ î£ù¢ Þòé¢è Ýóñ¢ð¤è¢è¤ù¢øù. ï£ñ¢ ê£î£óíñ£è ⿶ñ¢ main ( ) function Ýù¶ Applet ¹«ó£è¤ó£ñ¢è÷¤ô¢ Þòé¢è£¶. âù«õ main( ) function â¿îð¢ðì¢ì£ô¢ ܶ Java Application Ýè¾ñ¢, init( ) function â¿îð¢ðì¢ì£ô¢ Üî¬ù Java Applet Ýè¾ñ¢ ï¦é¢è÷¢ ªè£÷¢÷ «õí¢´ñ¢. init( ) function -ù¤ù¢ à÷¢ âù¢ù «õí¢´ñ£ù£½ñ¢ â¿î¤è¢ ªè£÷¢÷ô£ñ¢ âù¢ðî¬ù»ñ¢ Üî¤ô¤¼ï¢¶ î£ù¢ Appletè÷¢ Þòé¢è Ýóñ¢ð¤è¢è¤ù¢øù âù¢ðî¬ù»ñ¢ 郎ùõ¤ô¢ ªè£÷¢Àé¢è÷¢. public void paint(Graphics g) { ... } Þï¢î function Ýù¶ init ( ) function Þòé¢è¤ò ð¤ø° Ü´î¢î£è Þò颰ñ¢. ñø¢Áñ¢ âð¢ªð£¿ªîô¢ô£ñ¢ Applet ޼袰ñ¢ Window -õ¤ô¢ ñ£ø¢Áñ¢ ï¤èö¢è¤ù¢ø«î£ Üî£õ¶ minimize, maximize ºîô¤òù ïì袰ñ¢ ªð£¿¶ñ¢ Þï¢î paint function Ýù¶ î£ù£è Þò颰è¤ù¢ø¶. ï¦é¢è÷¢ internet explorer -ô¢ Üî£õ¶ Browser- ô¢ Next ñø¢Áñ¢ Back ºîô¤ò Button -è¬÷ Ü¿î¢î¤ ºù¢«ù ޼袰ñ¢ Page - è÷¢ ªêù¢Áõ¤ì¢´ ñ¢¹ñ¢ ªð£¿¶ paint function Þ¼ð¢ð¤ù¢ ܶ î£ù£è Þò颰ñ¢. Þï¢î paint( ) function -ô¢ Graphics âù¢ªø£¼ Class -ù¢ Object Ýù¶ Parameter Ýè âð¢ªð£¿¶ñ¢ Þ¼è¢è¤ù¢ø¶. Þî¬ù ðòù¢ð´î¢î¤ Line, Rectangle, Circle, Text ºîô¤ò Graphics êñ¢ðï¢îð¢ðì¢ì¬õè¬÷ õ¬ó ªè£÷¢÷ º®»ñ¢. import java.awt.Graphics; âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. awt âù¢ð¶ abstract windowing toolkit âù¢ðîù¢ ²¼è¢èñ¢ Ý°ñ¢. Þï¢î awt Package -ù¢ à÷¢÷¤¼è¢°ñ¢ ðô «õÁ class è¬÷è¢ ªè£í¢´î£ù¢ Graphical User Interface (GUI) ¹«ó£è¤ó£ñ¢è¬÷ â¿î Þò½ñ¢. Üî£õ¶ Label, Textbox, Combobox, Radio Button, Checkbox, Frame , Menu ºîô£ù ܬù windows êñ¢ðï¢îð¢ðì¢ì ¹«ó£è¤ó£ñ¤é¢°è¬÷»ñ¢ awt Package -ô¢ à÷¢÷ class è÷¤¬ùè¢ ªè£í¢«ì à¼õ£è¢è Þò½ñ¢. Þï¢î𢹫ó£è¤ó£ñ¤ô¢ ï£ñ¢ awt Package -ô¢ Þ¼è¢è¤ù¢ø Graphics âù¢Âñ¢ Package ¬ù ñ좴«ñ
- 45. 45 import ªêò¢î¤¼è¢è¤ù¢«ø£ñ¢.init( ) function -ù¤ô¢ resize (200, 150); âù¢ø function àð«ò£è¤è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þ¶ Applet -ô¢ Size Ýù¶ 200 ñø¢Áñ¢ 150 Pixels âù¢ø Ü÷¾è÷¤ô¢ õó«õí¢´ñ¢ âùê¢ ªê£ô¢õîø¢°ð¢ ðòù¢ð´è¤ù¢ø¶. «ñ½ñ¢ paint( ) function -ù¤ô¢ gdrawString(‘Hello World!‘, 50,10); âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þ颰 g âù¢ð¶ Graphics âù¢ø Class -ù¢ Object Ý°ñ¢. drawString Ýù¶ Graphics class -ù¢ Member function Ýùî£ô¢ Üî¬ù Þ颰 ðòù¢ð´î¢î¤è¢ ªè£÷¢÷ º®è¤ù¢ø¶. Þîù¢ Íôñ¢ ïñ袰 «õí¢®ò text -è¬÷ °ø¤ð¢ð¤ì¢ì row ñø¢Áñ¢ Column è÷¤ô¢ Üî£õ¶ Pixel- è÷¤ô¢ ޼ display ªêò¢¶ ªè£÷¢÷ º®»ñ¢. Þð¢ªð£¿¶ ï£ñ¢ ïñ¶ ºîô¢ Java Applet -®¬ù â¿î¤ º®î¢î¤¼è¢ è¤ù¢«ø£ñ¢. Þù¤ Þî¬ù âõ¢õ£Á Þòè¢è «õí¢´ñ¢ âù¢ðî¬ùè¢ è£í¢«ð£ñ¢. ê£î£óíñ£è java ¹«ó£è¤ó£ñ¢è¬÷ âõ¢õ£Á Compile ªêò¢«õ£«ñ£ Ü«î«ð£ô¢ Þï¢î ¹«ó£è¤ó£ñ¤¬ù»ñ¢ 覫ö ªè£´è¢èð¢ð좴÷¢÷¶ «ð£ô¢ compile ªêò¢¶è¢ ªè£÷¢Àé¢è÷¢. javac HelloworldApplet.java ¹«ó£è¤ó£ñ£ù¶ êó¤ò£è ޼袰ñ¢ ðì¢êî¢î¤ô¢ HelloworldApplet.Class âù¢ø file åù¢Á à¼õ£è¢è¤ò¤¼è¢°ñ.¢ Þð¢ªð£¿¶ ï£ñ¢ HelloworldApplet.class âù¢Âñ¢ Applet- ®¬ù Þò袰õîø¢è£è èì¢ì£òñ£è å¼ HTML file -ô¤¬ù à¼õ£è¢è¤ò£è «õí¢´ñ¢. Java Source code -®¬ù âï¢î Editor -ô¢ Type ªêò¢î¦ó¢è«÷£ Ü«î editor -ô¢ 覫ö ªè£´è¢ð¢ð좴÷¢÷ õó¤è¬÷𢠹î¤î£è Type ªêò¢¶ ªè£÷¢Àé¢è÷¢. <applet code="helloapplet.class" width=200 height=150> </applet> «ñ«ô ªè£´è¢èð¢ð좴÷¢÷õ£Á Type ªêò¢¶ º®î¢î¾ìù¢ plain ascii text format- ô¢ Üî£õ¶ ê£î£óí text file õ®õî¢î¤ô¢ myapplet.htm âù¢ø ªðòó¤¬ùè¢ ªè£´î¢¶ Save ªêò¢¶ ªè£÷¢Àé¢è÷¢. filename «õÁ ãî£õî£è Ãì ªè£´î¢¶è¢ ªè£÷¢÷ô£ñ¢. Ýù£ô¢ extension Ýù¶ .htm Üô¢ô¶ .html âù¢Á ªè£´è¢èð¢ðì «õí¢´ñ¢. àé¢èÀ袰 HTML ªîó¤ï¢î¤¼è¢°ñ¢ âù¢Á 郎ùè¢è¤ù¢«øù¢. Þô¢¬ô âù¢ø£½ñ¢ ðóõ£ò¤ô¢¬ô. Þï¢î HTML ªñ£ö¤ò¤ô¢ åõ¢ªõ£¼ °ø¤ð¢ð¤ì¢ì «õ¬ôèò¤¬ù»ñ¢ ªêò¢õîø¢è¢ªèù¢Á îù¤ò£è tagâù¢ø¬öè¢èð¢ð´ñ¢ èì¢ì¬÷è÷¢ Þ¼è¢è¤ù¢øù. Þõø¢ø¤ô¢ Applet-è¬÷ Browser-ô¢ Þò袰õîø¢° ðòù¢ð´ñ¢ èì¢ì¬÷ò£è <appletcode...>âù¢Âñ¢
- 46. 46 tagèì¢ì¬÷ð¢ ðòù¢ð´è¤ù¢ø¶. Þï¢î èì¢ì¬÷ò¤ô¢ Helloworld.Class âù¢Á ï£ñ¢ à¼õ£è¢è¤ò Java Class file ªè£´è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Height ñø¢Áñ¢ Width âù¢Á ªè£´è¢èð¢ð좴 Üõø¢ø¤øø° ñî¤ð¢¹è¬÷ ªè£´è¢èð¢ð좮¼ð¢ð¬î»ñ¢ èõù¤»é¢è÷¢. Þõø¢ø¤è¢° ñî¤ð¢¹è¬÷ èì¢ì£òñ£è ªè£´è¢è «õí¢´ñ¢. ãªùù¤ô¢ Þ¬õ«ò Applet -ù¢ ï¦÷, Üèôé¢è¬÷ º®¾ ªêò¢è¤ù¢øù. ï¦é¢è÷¢ Applet ¹«ó£è¤ó£ñ¢è¬÷ Java -õ¤ô¢ à¼õ£è¢è¤ù£ô¢ Üõø¢¬ø Þò袰õîø¢° èì¢ì£òñ£è HTML file -è¬÷ à¼õ£è¢è¤ Üõø¢ø¤ô¢ <applet code=‘HelloworldApplet.calss’ width=200 Height=150> </applet> âù¢ø õ¬èò¤ô¢ èì¢ì¬÷è¬÷ â¿î «õí¢´ñ¢. Þù¤ Applet -è¬÷ âõ¢õ£Á Þò袰õ¶ âù¢Á ð£ó¢ð¢«ð£ñ¢. Java Developement Kit (JDK) -ô¢ Applet Viewer â¿î¤ò tool Þ¼è¢è¤ù¢ø¶. Þî¬ùð¢ ðòù¢ð´î¢î¤ ï£ñ¢ â¿î¤ò Applet -è÷¢ êó¤ò£è Þò颰è¤ù¢øî£ âù¢ðî¬ùê¢ êó¤ð£ó¢î¢¶è¢ ªè£÷¢÷ô£ñ¢. 覫ö ªè£´è¢èð¢ ð좴÷¢÷¶ «ð£ô¢ ªè£´î¢¶ Applet Viewer -ø¤¬ù Þò袰é¢è÷¢. C:JDK1.2> appletviewer myapplet.Htm Þð¢ªð£¿¶ windows -ù¢ à÷¢ ªêù¢Á 覫ö ªè£´è¢èð¢ð좴÷¢÷¶ «ð£ô¢ AppletViewer Þò颰ñ¢. ÜîÂ÷¢ ï£ñ¢ â¿î¤ò Applet ¹«ó£è¤ó£ñ¢ Þò颰õ¬î»ñ¢ è£íô£ñ¢. ðì‹ðì‹ðì‹ðì‹ðì‹ 3.1
- 47. 47 appletviewer -ø¤¬ùî¢ îõ¤ó¢î¢¶ ï£ñ¢ «ïó®ò£è«õ Browser -è÷¤½ñ¢ Applet -è¬÷ Þòè¢è¤è¢ ªè£÷¢÷ô£ñ¢. â´î¢¶è¢è£ì¢ì£è InternetExplorerâÂñ¢ Browser ø¤¬ù Windows -ô¢ Open ªêò¢¶ ªè£÷¢Àé¢è÷¢. ðì‹ðì‹ðì‹ðì‹ðì‹ 3.2 Þï¢î Internet Exlorer Browser Ýù¶ open Ýè¤ò¾ìù¢ Üî¤ô¢ Þ¼è¢è¤ù¢ø Address Line-ô¢ ïñ¢º¬ìò HTMLfile âï¢î folder-ô¢ Þ¼è¢è¤ù¢ø«î£ Üî¬ùê¢ êó¤ò£è Ãø¤ file -ù¢ ªðòó¤¬ùè¢ ªè£´î¢«î£«ñò£ù£ô¢ ïñ¢º¬ìò Applet Ýù¶ Browse -ô¢ Þò颰ñ¢. ðì‹ðì‹ðì‹ðì‹ðì‹ 3.3
- 48. 48 «ñ«ô à÷¢÷ ðìî¢î¤ô¢ Þ¼ð¢ð¶ «ð£ô¢ àé¢èÀ¬ìò Applet êó¤ò£è Þò颰è¤ù¢øî£ âù¢ðî¬ùê¢ êó¤ð£ó¢î¢¶è¢ ªè£÷¢Àé¢è÷¢. Þð¢ªð£¿¶ ï£ñ¢ ïñ¢º ¬ìò ºîô¢ Java Applet -®¬ù ªõø¢ø¤èóñ£è Þòè¢è¤ º®î¢¶ Þ¼è¢è¤ù¢«ø£ñ¢. Abstract windowing toolkit (awt) Windows Operating System -î¢î¤ô¢ ï£ñ¢ ðòù¢ð´î¢¶ñ¢ ܬù ªñù¢ªð£¼÷¢ è÷¤½ñ¢ Textbox, Combobox, Radio Button, Push Button, Menu, Window ºîô£ù GUI Component-è¬÷ ªè£í¢´ ޼袰ñ¢. Þî¢î¬è«ò Component- è¬÷ ï£ñ¢ Java ¹«ó£è¤ó£ñ¤ô¢ ⿶õîø¢° Þï¢î Abstract Windowing ToolKit (AWT) âù¢Âñ¢ Package ðòù¢ð´è¤ù¢ø¶. Þù¤ Þï¢î Component -è¬÷ ªè£í¢´ ê¤ô Applet -è¬÷ à¼õ£è¢èô£ñ¢. Listing 3.2Listing 3.2Listing 3.2Listing 3.2Listing 3.2 import java.awt.*; import java.applet.Applet; public class student extends Applet { Label lbl_sname=new Label(“Student Name”); TextField txt_sname=new TextField(20); Label lbl_course=new Label(“Course Name”); Choice cho_course=new Choice(); Label lbl_sex=new Label(“Sex”); CheckboxGroup sex_grp=new CheckboxGroup(); Checkbox male=new Checkbox(“Male”,sex_grp,true); Checkbox female=new Checkbox(“Female”,sex_grp,false); Label lbl_time=new Label(“Time Prefered”); List lst_time=new List(); Label lbl_mop=new Label(“Mode Of Payment (Net/Install)”); Checkbox chk_mop=new Checkbox(); GridLayout abc=new GridLayout(5,2); Panel sex_pan=new Panel();
- 49. 49 public void init() { sex_pan.add(male); sex_pan.add(female); cho_course.addItem(“Java”); cho_course.addItem(“Visual Basic”); cho_course.addItem(“HTML”); cho_course.addItem(“XML”); lst_time.addItem(“Moring”); lst_time.addItem(“Afternoon”); lst_time.addItem(“Evening”); lst_time.addItem(“Night”); setLayout(abc); add(lbl_sname); add(txt_sname); add(lbl_course); add(cho_course); add(lbl_sex); add(sex_pan); add(lbl_time); add(lst_time); add(lbl_mop); add(chk_mop); } } Þï¢î𢠹«ó£è¤ó£ñ¤ô¢ ºîô¤ô¢ ï£ñ¢ awt ñø¢Áñ¢ Applet Ýè¤ò Package - è¬÷ import ªêò¢î¤¼è¢è¤ù¢«ø£ñ¢.
- 50. 50 public class student extends Applet âù¢Á ªè£´î¢î¤¼ð¢ðîù¢ Íôñ¢ student class Ýù¶ å¼ Applet Ýè ªêòô¢ð´ñ¢ñ£Á Inheritance ªêò¢òð¢ð좮¼è¢è¤ù¢ø¶. Label lbl_sname = new Label(‘Student Name’); TextField txt_sname = new TextField(20); âù¢Á ªè£´è¢èð¢ð좮ò¤¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þ颰 Label ñø¢Áñ¢ TextField ºîô¤òù awt -ò¤ô¢ Þ¼è¢è¤ù¢ø class -è÷¢ Ý°ñ¢. new operator -ø¤¬ùð¢ ðòù¢ð´î¢î¤ Þï¢î class -èÀ袰ø¤ò Object ´è¬÷ à¼õ£è¢è¤ò¤¼è¢è¤ù¢«ø£ñ¢. lbl_sname ñø¢Áñ¢ txt_sname Ýè¤òù º¬ø«ò Label ñø¢Áñ¢ TextField Ýè¤òõø¢ø¤ù¢ Object -´è÷¢ Ý°ñ¢. Label class -¬ìò Object -®¬ùð¢ ðòù¢ð´î¢î¤ ïñ袰 «õí¢®ò Text -è¬÷ display ªêò¢¶ ªè£÷¢÷ô£ñ¢. Ü«î«ð£ô¢ TextField class-ù¢ Object -¬ùð¢ ðòù¢ð´î¢î¤ ïñ袰 «õí¢®ò ñî¤ð¢¹è¬÷ Keyboard -®ô¢ ޼ à÷¢÷¦´è÷£è𢠪ðø¢Áè¢ ªè£÷¢÷ô£ñ¢. ï£ñ¢ ܬìð¢¹è¢ °ø¤è¢°÷¢ ªè£´è¢è¤ù¢ø ñî¤ð¢¹è¬÷ Üï¢îï¢î class-è÷¤ù¢ Constructor function -ø¢°ê¢ ªêô¢½ñ¢ Parameter ñî¤ð¢¹è÷¢ Ý°ñ¢. ܴ Choice cho_course = new choice( ); âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þ¶ Combo Box ¬ù ªè£í¢´ õ¼õîø¢è¢°ó¤ò class Ý°ñ¢. Þï¢î cho_course âù¢Âñ¢ Choice -ô¢ ïñ袰 «õí¢®ò Item -è÷¢ õó «õí¢´ñ¢ Üô¢ôõ£? Üîø¢° Choice class -ù¢ à÷¢ addItem âù¢Âñ¢ method åù¢Á à÷¢÷¶. Üî¬ùð¢ ðòù¢ð´î¢î¤è¢ ªè£÷¢÷ô£ñ¢. init( ) function -ù¤ô¢ cho_course (‘Java’); cho_course(‘Visual Basic’); âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þ¬õ ¹«ó£è¤ó£ñ¢ Þò颰ñ¢ ªð£¿¶ Combo box-ù¢ à÷¢ õõ¤´ñ¢ âù¢ðî¬ù 郎ùõ¤ô¢ ªè£÷¢Àé¢è÷¢. ܴ CheckboxGroup sex_grp = new CheckboxGroup ( ); Checkbox male = new Checkbox (‘Male’, sex_grp, true); Checkbox Female = new Checkbox (‘Female’, sex_grp, false); âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»éè÷¢. ªð£¶õ£è Checkbox âù¢ð¶ Ýñ¢ / Þô¢¬ô ºîô¤ò Þóí¢®ô¢ ãî£õ¶ åù¢ø¤¬ù ªîó¤¾ ªêò¢»ñ¢ð®ò£è ܬñï¢î¤¼è¢°ñ¢ Object -è¬÷ à¼õ£è¢°õîø¢°ð¢ ðòù¢ð´è¤ù¢ø¶. Þ«î
- 51. 51 Checkbox class àìù¢ CheckboxGroup âù¢Âñ¢ class -¬ù Þ¬í袰ñ¢ ªð£¿¶ ïñ袰 Radio Button-è÷¢ à¼õ£è¢è¤ù¢øù. Þï¢î𢠹«ó£è¤ó£ñ¤ô¢ Male, Female Ýè¤ò Þóí¢´ Radio Button -è¬÷ à¼õ£è¢°ñ¢ ªð£¼ì¢´ sex_grp âù¢Âñ¢ CheckboxGroup à¼õ£è¢èð¢ð좴 Üî¬ùè¢ ªè£í¢´ Þóí¢´ Checkbox Object- è÷¢ à¼õ£è¢èð¢ ð좴÷¢÷ù. Þõø¢ø¤ô¢ åù¢ø¤ô¢ True âù¢Áñ¢ ñø¢ªø£ù¢ø¤ô¢ false âù¢Âñ¢ ªè£´è¢èð¢ð좮´÷¢÷¶. True âù¢Á ªè£´î¢î£ô¢ Üï¢î Radio Button Ýù£¶ Selection -ù¤ô¢ ޼袰ñ¢ âù¢Á𢠪ð£¼÷¢. ܴ List lst_time = new List( ); âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þ¶ Listitem âù¢Áñ¢ õ¬èò¤¬ùê¢ ê£ó¢ï¢î Object -è¬÷ à¼õ£è¢° õîø¢è¢è£èð¢ ðòù¢ð´è¤ù¢ø¶. Þï¢î õ¬è Object -è÷¤½ñ¢ «õí¢®ò Item - è¬÷ à¼õ£è¢è¤è¢ ªè£÷¢÷ addItem method Ýù¶ ðòù¢ð´è¤ù¢ø¶. init ( ) function ù¤ô¢ lst_time.addItem(‘Morning’); lst_time.addItem(‘Afternoon’) ; âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þ¶õ¬ó ï£ñ¢ Label, TextField, Choice, Checkbox, CheckboxGroup ºîô¤ò awt class -è¬÷ð¢ ðòù¢ð´î¢î¤ âõ¢õ£Á object -è¬÷ à¼õ£è¢°õ¶ âù¢Á ð£ó¢î¢«î£ñ¢. Þõ¢õ£Á Object -è÷¢ à¼õ£è¢èð¢ ðì¢ì¾ì«ù«ò ܬõ Applet Screen -ô¢ ªîó¤ï¢¶ õ¤ì£¶. Üõø¢¬ø ï£ñ¢ º¬øò£è Applet -´ìù¢ Þ¬íè¢è «õí¢´ñ¢. Þîø¢° add( ) âù¢Âñ¢ function ðòù¢ ð´è¤ù¢ø¶. ï£ñ¢ âî¢î¬ù Object -è¬÷ à¼õ£è¢è¤ù£½ñ¢ ܬõ Screen -ô¢ ªîó¤ò «õí¢´ñ¢ âù¢ø£ô¢ Üîø¢° add function -¬ù è좮òñ£è ðòù¢ð´î¢î «õí¢´ñ¢ âù¢ 郎ùõ¤ô¢ ªè£÷¢Àé¢è÷¢. ïñ¢º¬ìò ¹«ó£è¤ó£ñ¤ô¢ add(1bs_sname); add(txt_sname); add(lbl_course); add(cho_course); âù¢Á à¼õ£è¢èð¢ðì¢ì ܬù object -èÀñ¢ add function -ù¤ù¢ õö¤ò£è º¬øò£è Applet -®ù¢ à÷¢ Þ¬íè¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þù¢Âñ¢ Þï¢î𢠹«ó£è¤ó£ñ¤ô¢ Þóí¢´ õ¤êòé¢è÷¢ èõù¤è¢èð¢ðì¢ì «õí¢®ò¤¼è¢è¤ù¢øù. ܬõ GridLayout ñø¢Áñ¢ Panel Ýè¤ò¬õè÷£°ñ¢. ªð£¶õ£è Java -õ¤ô¢ Object -è¬÷ º¬øò£è align ªêò¢õîø¢è¢ªèù¢Á Layout âù¢ø¬öè¢èð¢ð´ñ¢ å¼ Ü¬ñ𢹠޼è¢è¤ù¢ø¶. 5 õ¬èò£ù Layout - è÷¢ Java õ¤ô¢ Þ¼è¢è¤ù¢øù. Üõø¢ø¤ô¢ åù¢Á î£ù¢ Þï¢î GridLayout Ý°ñ¢.
- 52. 52 Þï¢î ¹«ó£è¤ó£ñ¤ô¢ GridLayout abc = new GridLayout(5,2); âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þï¢î Layout -®¬ùð¢ ðòù¢ð´î¢î¤ ïñ¢º¬ìò ¹«ó£è¤ó£ñ¤ô¢ âî¢î¬ù row ñø¢Áñ¢ column -è÷¢ Þ¼è¢è «õí¢´ñ¢ âù¢ðî¬ù õ¬óò¤¼è¢èô£ñ¢. Üîù¢ð® Þ颰 5 row -èÀñ¢ 2 Column -èÀñ¢ õ¼ñ£¼ õ®õ¬ñè¢èð ¢ð좮¼è¢è¤ù¢ø¶. Þ¶ «ð£ù¢Á à¼õ£è¢èð¢ð´ñ¢ Layout -è÷¢Effect Ýè «õí¢´ñ¢ âù¢ø£ô¢ Üî£õ¶ Þòé¢è «õí¢´ñ¢ âù¢ø£ô¢ SetLayout( ) âù¢Âñ¢ function -¬ù ðòù¢ð´î¢î¤ âï¢î Layout Ýù¶ Þòé¢è «õí¢´ñ¢ âù¢Á ªê£ô¢ô «õí¢´ñ¢. Üîù¢ð® init( ) function -ù¤ô¢ SetLayout(abc) âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þï¢î function ªè£´è¢èð¢ðì¢ì ð¤ù¢î£ù¢ add function-è÷¢ ªè£´è¢èð¢ð좴÷¢÷ù âù¢ðî¬ù èõù¤»é¢è÷¢. Üî£õ¶ Object ´è÷¢ Screen -ô¢ ªîó¤»ñ¢ ªð£¿¶ âîï¢î Object -è¬÷ ºîô¤ô¢ add ªêò¢è¤ù¢«ø£«ñ£ Üï¢î õó¤¬êò¤ô¢ 5 Row -è÷¤ô¢,å¼ Row -õ¤ø¢° 2 Column-è÷¢ âù¢ø õ¤è¤î¢î¤ô¢ Align Ýè¤õ¤´ñ¢. Þ¼î¤ò£è Panel sex_Pan = new Panel ( ) âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¬îè¢ ðø¢ø¤è¢ è£í¢«ð£ñ¢. Panel-è÷¢ âùð¢ð´¬õ ñ¤è¾ñ¢ ðòÂ÷¢÷ Object-è÷¢ Ý°ñ¢. å¼ Panel -ù¢ à÷¢ ðô¢«õÁ Object -è¬÷ Group ªêò¢¶ ªè£÷¢÷ô£ñ¢. Þõ¢õ£Á ðô¢«õÁ Object -è¬÷ ï£ñ¢ å¼ Panel Object -®ù¢ à÷¢ Group ªêò¢¶ õ¤ì¢ì ð¤ø° Üï¢î Panel -¬ù ñ좴ñ¢ ï£ñ¢ Þòè¢è¤ù£ô¢ «ð£¶ñ£ù¶. Þï¢î ¹«ó£è¤ó£ñ¤ô¢ ïñ¢º¬ìò ܬù Object -´èÀñ¢ Þóí¢´ Þóí¢´ Column -è÷£è õó¤¬êò£è Align Ýè «õí¢®ò¤¼è¢è¤ù¢ø¶. Üõ¢õ£Á ޼袰ñ¢ ªð£¿¶ Sex âù¢Á display ªêò¢õîø¢°ø¤ò Label Object-ñ¢ Ü«î «ïóî¢î¤ô¢ Male ñø¢Áñ¢ Female Ýè¤ò Þóí¢´ Radio Button -èÀñ¢ Ýè «êó¢î¢¶ ªñ£î¢îñ¢ Íù¢Á Object- èÀñ¢ å«ó row õ¤ù¤ô¢ Align Ýè «õí¢´ñ¢. Ýù£ô¢ ïñ¢º¬ìò GridLayout º¬øò¤«ô£ 5, 2 âù¢ø õ¬èò¤ô¢ å«ó column -î¢î¤ô¢ õó º®ò£¶. âù«õ ï£ñ¢ Male ñø¢Áñ¢ Female Ýè¤ò Þóí¢´ Object -è¬÷»ñ¢ sex_pan âù¢Âñ¢ Panel åù¢ø¤¬ù à¼õ£è¢è¤ ÜîÂ÷¢ add ªêò¢¶ õ¤´è¤ù¢«ø£ñ¢. Üî£õ¶ sex_pan.add(Female); âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þõ¢õ£Á Panel à¼õ£è¢è¤ò ð¤ù¢¹ Üï¢î Panel -¬ù ñ좴ñ¢ add ªêò¢¶ õ¤ì¢ì£ô¢ «ð£¶ñ£ù¶. âù«õî£ù¢ add(sex_pan); âù¢Á ªè£´î¢î¤¼è¢è¤ù¢«ø£ñ¢. Þï¢î º¿ ¹«ó£è¤ó£ñ¤¬ù»ñ¢ Type ªêò¢¶ õ¤ì¢´ student.java âù¢Á ªðòó¤ì¢´ ð¤ù¢ ºù¢ùó¢ °ø¤ð¢ð¤ì¢ì º¬øè÷¤ô¢ Compile ªêò¢¶ õ¤´é¢è÷¢. ܴ student.htm âù¢Âñ¢ file- ¬ù à¼õ£è¢è¤ Üî¤ô¢ ð¤ù¢õ¼ñ¢ õó¤è¬÷
- 53. 53 Type ªè£÷¢Àé¢è÷¢. <applet code="student.class" width=500 height=200> </applet> Þî¬ù appletviewer student.htm âù¢Á ªè£´î¢¶ Þòè¢è¤ð¢ ð£ó¢ð¦ó¢è÷£ù£ô¢ 覫ö ªè£´è¢èð¢ð좴÷¢÷¶ «ð£ù¢Á Þò颰ñ¢. ðì‹ðì‹ðì‹ðì‹ðì‹ 3.4 Listing 3.3 import java.awt.*; import java.awt.event.*; import java.applet.*; public class textsum extends Applet implements ActionListener { TextField x,y,tot; public void init() { Label xp=new Label(“X:”,Label.RIGHT); Label yp=new Label(“Y:”,Label.RIGHT);
- 54. 54 Label totp=new Label(“Total:”,Label.RIGHT); x=new TextField(5); y=new TextField(5); tot=new TextField(10); add(xp); add(x); add(yp); add(y); add(totp); add(tot); x.addActionListener(this); y.addActionListener(this); tot.addActionListener(this); } public void actionPerformed(ActionEvent ae) { int a,b,c; a=Integer.parseInt(x.getText()); b=Integer.parseInt(y.getText()); c=a+b; tot.setText(“” + c); } } Þï¢î𢠹«ó£è¤ó£ñ¤ô¢ x, y, tot âù¢Á Íù¢Á TextField object -è¬÷ à¼õ£è¢è¤ Üõø¢Á÷¢x ñø¢Áñ¢ y Ýè¤ò Object -è÷¤ô¢ Type ªêò¢òð¢ð´ñ¢ ñî¤ð¢¹è¬÷ Ã좮 tot âù¢Âñ¢ Object -ù¢ à÷¢ «ð£´ñ£Á â¿î¤ò¤¼è¢è¤ù¢«ø£ñ¢. ï£ñ¢ x ñø¢Áñ¢ y Ýè¤ò Object -è÷¤ô¢ ñî¤ð¢¹è¬÷ Type ªêò¢î ð¤ø° Enter Key ò¤¬ù Ü¿î¢î¤ò¾ìù¢ ïñ袰 Calculation ïìè¢è «õí¢´ñ¢ Üô¢ôõ£? Üîø¢è¢è£è ï£ñ¢ implements ActionListener âù¢Âñ¢ õ£è¢è¤òî¢î¤¬ù class-¬ù ⿶ñ¢ Þìî¢î¤ù¤ô¢ Þ¬íî¢î¤¼è¢è¤ù¢«ø£ñ¢. Üî£õ¶ public class textsum extends Applet implements ActionListener âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. ActionListener âù¢ð¶ å¼ Interface Ý°ñ¢. Þ¶ «ð£ù¢Á 郎øò Interface -è÷¢ Þ¼è¢è¤ù¢øù. ïñ袰
- 55. 55 «õí¢®ò Interface-¬ùð¢ ðòù¢ð´î¢î¤è¢ ªè£÷¢÷ implements âù¢Âñ¢ èì¢ì¬÷ ðòù¢ð´è¤ù¢ø¶. TextField x,y,tot; âù¢Á init( ) function-ø¢° «ñô¢ Global Ýè âù¢Á Íù¢Á Object ´è¬÷ define ªêò¢¶ ¬õî¢î¤¼è¢è¤ù¢«ø£ñ¢. ãªùù¤ô¢ Þõ¢õ£Á Global Ýè ⿶ñ¢ ªð£¿¶ textsum class -¬ìò ܬù method è÷¤½ñ¢ Üõø¢¬øð¢ ðòù¢ð´î¢î¤è¢ ªè£÷¢÷ô£ñ¢ âù¢ðî¬ù 郎ùõ¤ô¢ ªè£÷¢Àé¢è÷¢. init( ) function -ù¤ô¢ xp, yb, totp âù¢ø ªðòó¢è÷¤ô¢ Íù¢Á Label Object -è÷¢ à¼õ£è¢èð¢ð좮¼è¢è¤ù¢øù. ܬõ Right align Ýõîø¢è¢è£è Label.RIGHT âù¢Á ªè£´è¢èð¢ð좮¼è¢è¤ù¢ø¶. x, y, tot Ýè¤ò object-è÷¢ new operator -ø¤¬ùð¢ ðòù¢ð´î¢î¤ à¼õ£è¢èð ¢ðì¢ìð¤ù¢ ܬõ add function Íôñ¢ õó¤¬êò£è Applet -®Â÷¢ add ªêò¢òð¢ ð좮¼è¢è¤ù¢øù. ï£ñ¢ Þï¢î ¹«ó£è¤ó£ñ¤ô¢ ºè¢è¤òñ£è èõù¤è¢è «õí¢®ò¶. x.addActionListener(this); y.addActionListener(this); tot.addActionListener(this); âù¢Âñ¢ õó¤è¬÷î¢î£ù¢. Üî£õ¶ Þï¢î addActionListener( ) âù¢Âñ¢ function -ä ªè£´ð¢ðîù¢ Íôñ¢, âð¢ªð£¿¶ªîô¢ô£ñ¢ ï£ñ¢ Þï¢î Object ´è÷¤ô¢ Enter Key ò¤¬ù ܿè¤ù¢«ø£«ñ£ Üð¢ªð£¿ªîô¢ô£ñ¢ actioPerformed âù¢Âñ¢ event Ýù¶ î£ù£è Þòé¢è¤õ¤´ñ¢. Public void actionperformed(ActionEvent ae) âù¢ø õ®õ¤ô¢ ޼袰ñ¢ Þï¢î Event Ýù¶ ActionListener âù¢Âñ¢ Interface -¬ù Þï¢î ¹«ó£è¤ó£ñ¤ô¢ implement ªêò¢î¤¼ð¢ðîù£ô¢ î£ù¢ ðòù¢ð´î¢îð¢ð´è¤ù¢ø¶ âù¢ðî¬ù 郎ùõ¤ô¢ ªè£÷¢Àé¢è÷¢. Þï¢î actionperformed( ) function -ô¢ ï£ñ¢ a, b, c âù¢Á Íù¢Á integer variable-è¬÷ int data type -ù¤ô¢ à¼õ£è¢è¤ò¤¼è¢è¤ù¢«ø£ñ¢. Þï¢î variable è÷¤ô¢ ï£ñ¢ x, y TexField è÷¤ô¢ Type ªêò¢î ñî¤ð¢¹è¬÷ â´î¢¶ð¢ «ð£´è¤ù¢«ø£ñ¢. a = Integer.ParseInt(x.getText ( )); b = Integer.ParseInt(y.getText ( )); âù¢Á ªè£´î¢î¤¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þî¤ô¢ getText âù¢ð¶ TextField class -ù¢ member function Ý°ñ¢. Þî¬ùð¢ ðòù¢ð´î¢¶ñ¢ ªð£¿¶ ï£ñ¢ âù¢ù ñî¤ð¢¹è¬÷ TextField-è÷¤ù¢ à÷¢ Type ªêò¢î¤¼è¢è¤ù¢«ø£«ñ£ Üõø¢¬øð¢
- 56. 56 ªðø¢Á袪è£÷¢÷ô£ñ¢. Þï¢î º¬øò¤ô¢ ï£ñ¢ TextField -è÷¤ô¢ ޼袰ñ¢ ñî¤ð¢¹è¬÷ ªð¼ñ¢ªð£¿¶ ܬõ String data type Ýè ޼袰ñ¢. Þõø¢¬ø int data type Ýè ñ£ø¢ø¤ù£ô¢ î£ù¢ ïñ袰 Calculation è¬÷ê¢ ªêò¢ò º®»ñ£îô£ô¢ Integer.ParseInt âù¢Âñ¢ function ù¤¬ùð¢ ðòù¢ð´î¢î¤ò¤¼è¢è¤ù¢«ø£ñ¢. Þï¢î Integer.ParseInt function Ýù¶ String õ®õ¤ô¢ ޼袰ñ¢ Number è¬÷ Integer data type Ýè ñ£ø¢ø¤è¢ ªè£´î¢¶õ¤´ñ¢. ܴ c = a + b; âù¢Á ªè£´î¢î¤¼ð¢ðîù¢ Íôñ¢ x , y Object -®ô¢ à÷¢÷ ñî¤ð¢¹è¬÷ Ã좮 c âÂñ¢ variable-ô¢ «ð£ì¢´ õ¤ì¢«ì£ñ¢. Þð¢ªð£¿¶ Þï¢î c ò¤ô¢ à÷¢÷ ñî¤ð¢ð¤¬ù tot âù¢Âñ¢ TextField -ù¢ à÷¢ «ð£ì «õí¢´ñ¢ Üô¢ôõ£? Üîø¢° TextField class -ô¢ à÷¢÷ setText âù¢Âñ¢ function ðòù¢ð´î¢îð¢ð´è¤ù¢ø¶. tot.setText (“” + c); âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. SetText function -ù¤ù¢ Íôñ¢ String data è¬÷ ñ좴«ñ â¿î º®»ñ£îô£ô¢ c ò¤ô¢ à÷¢÷ Integer ñî¤ð¢¹è¬÷ type cast ªêò¢õîø¢è¢è£è “” + c âù¢Á String -°ìù¢ «êó¢î¢¶è¢ ªè£´î¢î¤¼è¢è¤ù¢«ø£ñ¢. Þï¢î𢠹«ó£è¤ó£ñ¤¬ù compile ªêò¢¶ 覫ö ªè£´è¢èð¢ð좴÷¢÷õ£Á à÷¢÷ õó¤è¬÷ð¢ ðòù¢ð´î¢î¤ HTML file åù¢ø¤¬ù à¼õ£è¢è¤ Üî¬ù Þòè¢è¤ð¢ ð£¼é¢è÷¢. <applet code="textsum.class" width=500 height=400> </applet>
- 57. 57 ðì‹ðì‹ðì‹ðì‹ðì‹ 3.5 Listing 3.4 import java.awt.*; import java.applet.*; import java.util.*; public class border extends Applet { Button top = new Button(“Top”); Button bottom = new Button(“Bottom”); Button right = new Button(“Right”); Button left = new Button(“Left”); String msg=”Java is intresting.......”; TextArea hi = new TextArea(msg); public void init()
- 58. 58 { BorderLayout abc = new BorderLayout(); setLayout(abc); add(top,BorderLayout.NORTH); add(bottom,BorderLayout.SOUTH); add(right,BorderLayout.WEST); add(left,BorderLayout.EAST); add(hi,BorderLayout.CENTER); } public boolean action(Event evt,Object arg) { if(evt.target instanceof Button) { String lab=(String)arg; if (lab.equals(“Top”)) { hi.setText(“I am in Top”); } if (lab.equals(“Bottom”)) { hi.setText(“I am in Bottom”); } if (lab.equals(“Left”)) { hi.setText(“I am in Left”); } if (lab.equals(“Right”)) { hi.setText(“I am in Right”); } } return true; }
- 59. 59 } Þï¢î ¹«ó£è¤ó£ñ¤ô¢ ï£ñ¢ Push Button âù¢Á ܬöè¢èð¢ðìè¢Ã®ò Button -è¬÷ âõ¢õ£Á à¼õ£è¢è¤ ðòù¢ð´î¢¶õ¶ âù¢Á è£í¢è¤ù¢«ø£ñ¢. Button top = new Button (“Top”); âù¢ø õ¬èò¤ô¢ Button âù¢Âñ¢ class -¬ùð¢ ðòù¢ð´î¢î¤ Object -è÷¢ à¼õ£è¢èð¢ ð좮¼ð¢ð¬îè¢ è£í¢è¤ù¢ø¦ó¢è÷¢. top, bottom, right, left âù¢Á ï£ù¢° Button è÷¢ à¼õ£è¢èð¢ð좮¼è¢è¤ù¢øù. String msg = “Java is interesting ....”; Text rea hi = new TextArea(msg); âù¢Á ªè£´î¢î¤¼ð¢ðîù¢ Íôñ¢ ï£ñ¢ å¼ TextArea object -¬ù à¼õ£è¢è¤ ò¤¼è¢è¤ù¢«ø£ñ¢. Þï¢î TextArea-è÷¢ ðô õó¤è¬÷ ªè£í¢ì Text Paragraph - è¬÷ à÷¢÷¦´è÷£è𢠪ð¼õîø¢°ñ¢, display ªêò¢õîø¢°ñ¢ ðòù¢ð´è¤ù¢øù. Object-è¬÷ à¼õ£è¢è¤ò ð¤ù¢ init( ) function -ô¢ BorderLayout abc = new BorderLayout( ); SetLayout (abc); âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þ¶ Java-õ¤ô¢ ޼袰ñ¢ 5 Layout õ¬èè÷¤ô¢ åù¢ø£°ñ¢. Þï¢î BorderLayout -¬ùð¢ ðòù¢ð´î¢î¤ ï¦é¢è÷¢ Object- è¬÷ Top, Bottom, Left, Right, Center âù¢ø ä ͬôè÷¢è÷¤ô¢ Align ªêò¢¶ ªè£÷¢÷ô£ñ¢. Object -è¬÷ Applet -ô¢ add ªêò¢»ñ¢ ªð£¿¶, add(top,BorderLayout.NORTH); add(bottom,BorderLayout.SOUTH); âù¢ø õ¬èò¤ô¢ âï¢î Þìî¢î¤ô¢ ܬõ õó «õí¢´ñ¢ âù¢Á °ø¤ð¢ð¤´õ¬îè¢ èõù¤»é¢è÷¢. Þð¢ªð£¿¶ ï£ñ¢ Button -è¬÷ à¼õ£è¢è¤ Üõø¢¬ø Applet -½ñ¢ add ªêò¢¶ õ¤ì¢«ì£ñ¢. ¹«ó£è¤ó£ñ¢ Þò颰ñ¢ ªð£¿¶ ï£ñ¢ Üï¢î Button è¬÷ ܿ«õ£«ñò£ù£ô¢ (Press) âù¢ù ïìè¢è «õí¢´ñ¢ âù¢ðîø¢°ø¤ò ¹«ó£è¤ó£ñ¤¬ù â¿î «õí¢´ñ¢ Üô¢ôõ£? Üîø¢°, public boolean action(Event evt, object arg) âù¢ø event åù¢Á â¿îð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þï¢î action Event Ýù¶ âð¢ªð£¿ªîô¢ô£ñ¢ Button,Choice ºîô¤ò Class è÷¤ù¢ Object-è¬÷ Press ðù¢Âñ¢«ð£¶ñ¢ î£ù£è Þòé¢è¤õ¤´ñ¢. Þï¢î actionEvent-¬ùð¢ ðòù¢ ð´î¢¶õîø¢° âï¢îªõ£Á interface -»ñ¢ Implement ªêò¢òî¬õò¤ô¢¬ô âù¢ðî¬ù 郎ùõ¤ô¢ ªè£÷¢Àé¢è÷¢. Þòø¢è¢¬èò£è«õ Event ñø¢Áñ¢ Object âù¢ø Þóí¢´ class è÷¤ù¢ variable è÷¢ parameter
- 60. 60 Þ¼ð¢ðîù£ô¢, Þõø¢ø¤ô¢ ï£ñ¢ âï¢î Button,Choiceºîô¤ò Object-¬ù Click ªêò¢è¤ù¢«ø£ñ¢ «ð£ù¢ø îèõô¢è÷¢ õ õ¤´è¤ù¢øù. if(evt.target instanceOf Button) âù¢ø õó¤ò¤¬ù èõù¤»é¢è÷¢ Þ颰 instanceOf âù¢ð¶ Java -õ¤ô¢ ޼袰ñ¢ å¼ Keyword Ý°ñ¢. Þî¬ùð¢ ðòù¢ð´î¢î¤ å¼ variable Ýù¶ âï¢î class- ä ê£ó¢ï¢¶ Þ¼è¢è¤ù¢ø¶ âù¢ðî¬ù Üø¤ï¢¶ ªè£÷¢÷ô£ñ¢. ï£ñ¢ Button object åù¢ø¤¬ù click ªêò¢î¤¼ï¢î£ô¢ Þï¢î if condition ù¤ù¢ à÷¢ ï£ñ¢ ªêô¢ô º®»ñ¢. Üõ¢õ£Á ªêô¢½ñ¢ ªð£¿¶ arg âù¢Âñ¢ parameter variable -ô¢ ï£ñ¢ click ªêò¢î Button -ù¤ù¢ caption Ýù¶ ޼袰ñ¢ ܬî String õ¬èò£ùî£è cast ªêò¢¶ å¼ String varible -ô¢ «ð£´è¤ù¢«ø£ñ¢. Þï¢î String variable -ù¢ à÷¢ âù¢ù ñî¤ð¢¹ Þ¼è¢è¤ù¢ø¶ âù¢ðî¬ù equals âù¢Âñ¢ function -ä ¬õî¢¶è¢ èí¢´ð¤®î¢¶ Üîù¢ Ü®ð¢ð¬ìò¤ô¢ âï¢î Button- ù¤¬ù click ªêò¢«î£ñ¢ âù¢ðî¬ù Üø¤òô£ñ¢. Þ颰 åõ¢ªõ£¼ Button Ýè click ªêò¢î£ô¢, âù¢ù ªêò¢ò «õí¢´ñ¢ âù¢Á îù¤î¢îù¤ò£è ¹«ó£è¤ó£ñ¢ â¿îð¢ð좴÷¢÷¶. Þ¼î¤ò£è return true; âù¢Á ªè£´è¢èð¢ð좴÷¢÷¬îè¢ èõù¤»é¢è÷¢. Þî¬ù èí¢®ð¢ð£è ªè´è¢è «õù¢´ñ¢. ãªùù¤ô¢ boolean data type-¬ù return data type Ýè ªè£í¢´÷¢÷¶. trueâù¢Á ªè£´î¢î£ô¢event ªõø¢ø¤èóñ£è Þòé¢è¤ò¶ âù¢Á ªð£¼÷¢. Þ颰 False âù¢Áñ¢ ªè£´è¢èô£ñ¢ âù¢ðî¬ù 郎ùõ¤ô¢ ªè£÷¢Àé¢è÷¢. Üõ¢õ£ªøù¤ô¢ event ªõø¢ø¤èóñ£è Þòé¢èõ¤ô¢¬ô âù¢Á ªð£¼÷¢. ðì‹ðì‹ðì‹ðì‹ðì‹ 3.6
- 61. 61 Listing 3.5 import java.awt.*; import java.applet.Applet; public class gridb extends Applet { protected void addGridBagButton(String buttonName, GridBagLayout gb,GridBagConstraints gbc) { Button button=new Button(buttonName); gb.setConstraints(button,gbc); add(button); } public void init() { resize(400,300); GridBagLayout gridbag=new GridBagLayout(); GridBagConstraints c=new GridBagConstraints(); setLayout(gridbag); c.fill=GridBagConstraints.BOTH; c.weightx=1.0; addGridBagButton(“Button1”,gridbag,c); c.gridwidth=GridBagConstraints.REMAINDER; addGridBagButton(“Button2”,gridbag,c); addGridBagButton(“Button3”,gridbag,c); c.weighty=1.0; addGridBagButton(“Button4”,gridbag,c); c.gridwidth=1; c.weighty=0.0; addGridBagButton(“Button5”,gridbag,c); c.weightx=0.0; addGridBagButton(“Button6”,gridbag,c); c.gridwidth=GridBagConstraints.REMAINDER;
- 62. 62 addGridBagButton(“Button7”,gridbag,c); c.gridwidth=1; c.gridheight=2; c.weighty=1.5; addGridBagButton(“Button8”,gridbag,c); c.weighty=0.0; c.gridwidth=GridBagConstraints.REMAINDER; c.gridheight=1; addGridBagButton(“Button9”,gridbag,c); addGridBagButton(“Button10”,gridbag,c); c.weighty=1.0; addGridBagButton(“Button11”,gridbag,c); c.weighty=0.0; addGridBagButton(“Button12”,gridbag,c); } } Þ颰 ¹«ó£è¤ó£ñ¤ô¢ GridBagLayout âù¢ø Layout º¬ø ðòù¢ð´î¢îð¢ ð좮¼è¢è¤ù¢ø¶. Þï¢î Layout -ù¢ Íôñ¢ Object -è¬÷ «õí¢®ò ï¦÷ñ¢ ñø¢Áñ¢ Üèôé¢è÷¤ô¢ °ø¤ð¢ð¤ì¢ì row ñø¢Áñ¢column-î¢î¤ô¢align ªêò¢õîø¢°ð¢ ðòù¢ ð´è¤ù¢ø¶. GridBagLayout gridbag = new GridBagLayout( ); GridBagConstraints c = new GridBagConstraints( ); âù¢ø ªè£´è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þî¤ô¢ GridBagLayout âù¢ð¶ ïñ¢º¬ìò Layout Ý°ñ¢. Þï¢î Layout -ô¢ ïñ¢º¬ìò Object -è÷¢ âï¢î Row, Column Ýè¤ò Þìî¢î¤ô¢ Þ¼è¢è «õí¢´ñ¢ ñø¢Áñ¢ âõ¢õ£Á ï¦÷ Üèôé¢è¬÷ ªè£í¢®¼è¢è«õí¢´ñ¢ «ð£ù¢ø Ü÷¾è¬÷è¢ ªè£´ð¢ðîø¢°GridBagConstraintsâù¢ø Class ¬ìò Object -è÷¢ ðòù¢ð´è¤ù¢øù.Þï¢î class -ù¢ à÷¢ fill, weightx, weighty, gridWidth,gridHeight,gridx,gridy âù¢Á ðô Propertyvariable-è÷¢ Þ¼è¢è¤ù¢øù. Þõø¢ø¤ô¢ «õí¢®ò ñî¤ð¢¹è¬÷ ªè£´î¢¶õ¤ì¢´ ð¤ù¢ùó¢ ܬõ âï¢î Object -ø¢° apply Ýè «õí¢´ñ¢ âù¢Áñ¢ ªê£ô¢ô«õí¢´ñ¢. Þï¢î ¹«ó£è¤ó£ñ¤ô¢ ConstraintVariable è÷¤ô¢ ñî¤ð¢¹è¬÷ Set ªêò¢õîø¢è¢ ªèù¢«ø
- 63. 63 addGridBagButton âù¢Âñ¢ function â¿îð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þï¢î function -ô¢ «õí¢®ò Button Object -è¬÷ Üõø¢ø¤è¢°î¢ «î¬õò£ù constraint ñî¤ð¢¹è÷¤ô¢ assign ªêò¢¶ ªè£÷¢÷ô£ñ¢. ðì‹ðì‹ðì‹ðì‹ðì‹ 3.7 Listing 3.6 import java.awt.*; import java.applet.Applet; import java.awt.event.*; public class cardtest extends Applet { CardLayout card = new CardLayout(); public void init() { resize(400,300); setLayout(card); Panel p1 = new Panel(); p1.add(new Button(“This is a button on Panel One”)); add(p1,””);
- 64. 64 addMouseListener(p1); Panel p2 = new Panel(); p2.add(new Button(“This is a button on Panel Two”)); add(p2,””); addMouseListener(p2); Panel p3 = new Panel(); p3.add(new Button(“This is a button on Panel Three”)); add(p3,””); addMouseListener(p3); Panel p4 = new Panel(); p4.add(new Button(“This is a button on Panel Four”)); add(p4,””); addMouseListener(p4); card.first(this); } void addMouseListener(Panel p) { p.addMouseListener(new MouseAdapter() { public void mousePressed(MouseEvent e) { card.next(cardtest.this); } }); } } Þï¢î ¹«ó£è¤ó£ñ¤ô¢ CardLayout âù¢Âñ¢ Layout º¬ø õ¤÷è¢èð¢ð좴÷¢÷¶.
- 65. 65 Þï¢î Layout º¬øò¤ô¢ å«ó «ïóî¢î¤ô¢ å«ó å¼ Component -¬ù ñ좴«ñ display ªêò¢¶ ªè£÷¢÷ º®»ñ¢. âù«õ ï£ñ¢ ðô¢«õÁ Panel -è¬÷ à¼õ£è¢è¤ Üõø¢ø¤ô¢ ªõõ¢«õÁ Layout -è¬÷ ªêò¢¶ ªè£÷¢÷ô£ñ¢. Ýù£ô¢ Þï¢î Panel -è¬÷ åõ¢ªõ£ù¢ø£èî¢î£ù¢ CardLayout -ô¢ display ªêò¢¶ ªè£÷¢÷ º®»ñ¢ âù¢ðî¬ù 郎ùõ¤ô¢ ªè£÷¢Àé¢è÷¢. ðì‹ðì‹ðì‹ðì‹ðì‹ 3.8 Þï¢î ¹«ó£è¤ó£ñ¤ô¢ ðô Panel-è÷¢ à¼õ£è¢èð¢ð좮¼è¢è¤ù¢øù. Üõø¢¬øè¢ Click ªêò¢î¾ìù¢ åõ¢ªõ£Á Panel Ýè ñ£ø¢ø¤ display ªêò¢»ñ¢ð®è¢° card.next(cardtest.this) âù¢Âñ¢ function ðòù¢ð´î¢îð¢ð좮¼è¢è¤ù¢ø¶. °ø¤ð¢¹°ø¤ð¢¹°ø¤ð¢¹°ø¤ð¢¹°ø¤ð¢¹ Þ¶õ¬ó ï£ñ¢ FlowLayout, GridLayout, GridBagLayout, BorderLayout, CardLayout âù¢Âñ¢ ä õ¬è Layout-è¬÷ ðòù¢ð´î¢î¤ âõ¢õ£Á awt Package-ô¢ à÷¢÷ TextField, Label, Button ºîô£ù ðô¢«õÁ Object -è¬÷ à¼õ£è¢°õ¶ âù¾ñ¢, Üõø¢¬ø ðòù¢ð´î¢¶ñ¢ ªð£¿¶ âù¢ù ïìè¢è «õí¢´ñ¢ âù¢Á ªê£ô¢õîø¢è¢°ø¤ò Event-è¬÷ âõ¢õ£Á ¬èò£÷¢õ¶ âù¢ðî¬ù»ñ¢ Üø¤ï¢î¤¼è¢è¤ù¢«ø£ñ¢. Windows Application abstract windowing toolkit (awt) Package-ô¢ à÷¢÷ Component-è¬÷ð¢
- 66. 66 ðòù¢ð´î¢î¤ Þ¶õ¬ó applet -è¬÷ âõ¢õ£Á à¼õ£è¢°õ¶ âù¢Á ð£ó¢î¢î¤¼è¢ è¤ù¢«ø£ñ¢. Þ«î awt Package -ô¢ à÷¢÷ Component-è¬÷ ªè£í¢´ Windows Operating System -î¢î¤ô¢ «õ¬ô ªêò¢»ñ¢ Application-è¬÷»ñ¢ à¼õ£è¢è º®»ñ¢. Visual Basic ºîô£ù GUI Package è¬÷ à¼õ£è¢°õ¶ «ð£ù¢«ø ܬù õ¬èò£ù Application -è¬÷»ñ¢ Java-õ¤ô¢ à¼õ£è¢è Þò½ñ¢. ªð£¶õ£è windows -ô¢ å¼ Application Þòé¢è «õí¢´ñ¢ âù¢ø£ô¢ Üï¢î Application -ø¢° âù¢Á å¼ window frame Þ¼è¢è «õí¢´ñ¢ Üô¢ôõ£? Üî£õ¶ TitleBar, Minimize Button, Maximize Button, Close Box Ýè¤òõø¢¬ø ªè£í¢ì Frame åù¢Á Üõñê¤òñ¢. Üî¢î¬èò Frame åù¢ø¤¬ù à¼õ£è¢è¤ Üî¤ô¢ ïñ¢º¬ìò Component-è¬÷ «ð£ì¢´î¢ ªè£÷¢÷ô£ñ¢. °ø¤ð¢ð£è Application åù¢ø¤¬ù â¿î «õí¢´ñ¢ âù¢ø£ô¢ main( ) function- ô¢ î£ù¢ ¹«ó£è¤ó£ñ¤¬ù â¿î «õí¢´ñ¢ âù¢ðî¬ù âð¢ªð£¿¶ñ¢ 郎ùõ¤ô¢ ªè£÷¢Àé¢è÷¢. Listing 3.7 import java.awt.*; import java.awt.event.*; public class appl { public static void main(String a[]) { Frame baskar=new Frame(“Application”); baskar.resize(300,300); baskar.show(); } } Þï¢î ¹«ó£è¤ó£ñ¤ô¢ ï£ñ¢ main ( ) function ù¤¬ù ðòù¢ð´î¢î¤ò¤¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. âù«õ Þ¶ å¼ Application Ý°ñ¢. Þî¤ô¢ Frame xyz = new Frame(‘Application’); âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þï¢î class-ù¢ Íôñ¢ ïñ袰 å¼ Window frame 褬ìè¢è¤ù¢ø¶. constructors-ô¢ ªè£´è¢°ñ¢ String Ýù¶ window õ¤ù¢ Title Ýè õ¼è¤ù¢ø¶. Þï¢î window õ£ù¶ âï¢î ï¦÷ñ¢ ñø¢Áñ¢
- 67. 67 Üèôî¢î¤ô¢ õó«õí¢´ñ¢ âù¢ðîø¢è¢è£è xyz.resize(300,300); âù¢Âñ¢ member function ù¤¬ù ðòù¢ð´î¢î¤ò¤¼è¢è¤ù¢«ø£ñ¢. Þ¼î¤ò£è xyz.show ( ); âù¢Á ªè£´è¢°ñ¢ ªð£¿¶ ïñ¢º¬ìò frame Ýù¶ Display Ýè¤ù¢ø¶. Þî¬ù javac appl.java âù¢Á ªè£´î¢¶ Compile ªêò¢¶ õ¤ì¢´ java appl âù¢Á ªè£´î¢¶ Run ªêò¢¶ ð£¼é¢è÷¢. ðì‹ðì‹ðì‹ðì‹ðì‹ 3.9 «ñø¢èí¢ìõ£Á window ªîó¤õî¬ùè¢ è£íô£ñ¢. Þï¢î window - õ¤ù¤ô¢ ªîó¤è¤ù¢ø Minimize ñø¢Áñ¢ Maximize Button-è÷¢ ºîô¤òù Þò颰ñ¢. Ýù£ô¢ Close Button Ýù¶ Þòé¢è£¶. ãªùù¤ô¢ Üîø¢è¢ªèù¢Á îù¤ò£è Event åù¢ø¤¬ù â¿î «õí¢´ñ¢. âù«õ Þï¢î ¹«ó£è¤ó£ñ¢ Þò颰ñ¢ ªð£¿¶ Dos Prompt-ô¢ Ctrl+C âù¢Á Shortcut key ò¤¬ùð¢ ðòù¢ð´î¢î¤ ¹«ó£è¤ó£ñ¤ù¢ Þòè¢èî ï¤Áî¢î¤è¢ ªè£÷¢Àé¢è÷¢. Listing 3.8 import java.awt.*;
- 68. 68 import java.awt.event.*; public class my_app { Frame my_frm=new Frame(“My Application”); Label lname=new Label(“User Name”); TextField tname=new TextField(20); Label lpass=new Label(“Password”); TextField tpass=new TextField(20); my_app() { my_frm.addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent e) { System.exit(0); } }); tpass.setEchoChar(‘x’); Panel my_pan=new Panel(); my_pan.setLayout(new GridLayout(2,2)); my_pan.add(lname); my_pan.add(tname); my_pan.add(lpass); my_pan.add(tpass); BorderLayout xyz=new BorderLayout(); my_frm.setLayout(xyz); my_frm.add(my_pan,BorderLayout.CENTER);
- 69. 69 my_frm.resize(250,100); my_frm.show(); } static void main(String argv[]) { my_app hello=new my_app(); } } Þï¢î𢠹«ó£è¤ó£ñ¤ô¢ my_frm âù¢ªø£¼ frame à¼õ£è¢èð¢ð좮¼è¢è¤ù¢ø¶. lname, lpass âù¢Á Þóí¢´ Label Object-èÀñ¢ ñø¢Áñ¢ tname, tpass âù¢Á Þóí¢´ TextField object-èÀñ¢ à¼õ£è¢èð¢ð좴÷¢÷ù. Þï¢î Object-è÷¢ Þï¢î Frame ù¤ô¢ õ¼õîø¢è¢è£è ¹«ó£è¤ó£ñ¢ â¿îð¢ð좴÷¢÷¶. my_app( ) âù¢Á å¼ Con- structor function â¿îð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. ÞîÂ÷¢ ï£ñ¢ ܬù initialize «õ¬ôè¬÷»ñ¢ ªêò¢î¤¼è¢è¤ù¢«ø£ñ¢. main ( ) function ù¤ô¢ my_app hello = new my_app( ); âù¢Á ïñ¢º¬ìò class -ø¢° å¼ Object à¼õ£è¢èð¢ð´õ¬îè¢ èõù¤»é¢è÷¢. Þï¢î Object à¼õ£°ñ¢ ªð£¿¶ Üï¢î Object -ô¢ à÷¢÷ Class-ù¢ ܬù Variable èÀñ¢ à¼õ£è¢èð¢ð좴 Constructor Function -Âñ¢ î£ù£è Þòé¢è
- 70. 70 Ýóñ¢ð¤è¢è¤ù¢ø¶. Constructor Function ù¤ù¢ à÷¢ my_frm.addwindowListener(new windowAdopter( ) { public void windowClosing (WindowEvent e ) { System.exit(0); } }); âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þ¶ ïñ¢º¬ìò frame Ýù my_frm object-ù¢ Close Button ù¤¬ù click ªêò¢î£ô¢ Þò颰ñ¢ event Ý°ñ¢. System.exit (0); function Ýù¶ Application-ù¤ù¢ Þòè¢èî 祿è¤ù¢ø¶. ð¤ù¢ my_pan âù¢ø Panel åù¢Á à¼õ£è¢èð¢ð좴 Üî¤ô¢ GridLayout Ýù¶ Set ªêò¢òð¢ð좮¼è¢è¤ù¢ø¶. Üîù¢ à÷¢ ïñ¢º¬ìò lname, tname, lpass, tpass Ýè¤ò Object-è÷¢ Þ¬íè¢èð¢ð´è¤ù¢øù. Þï¢îð¢ Panel -¬ù ïñ¢º¬ìò frame à÷¢ Þ¬í袰ñ¢ ºù¢ BorderLayout object åù¢Á à¼õ£è¢èð¢ð좴 ܶ frame ¬ìò Layout Ýè Set ªêò¢òð¢ð´è¤ù¢ø¶. ð¤ù¢ùó¢ Panel Object Ýù¶ frameù¢ à÷¢add ªêò¢òð¢ð´è¤ù¢ø¶. ð¤ù¢ùó¢ frame resize ªêò¢òð¢ð좴 show ªêò¢òð¢ð´ è¤ù¢ø¶. ðì‹ðì‹ðì‹ðì‹ðì‹ 3.10
- 71. 71 Menu Program Listing 3.9 import java.awt.*; import java.awt.event.*; public class menu { public static void main(String a[]) { Frame my_frm=new Frame(“Menu Programme”); MenuBar bar = new MenuBar(); Menu File = new Menu(“File”); Menu Edit = new Menu(“Edit”); // MenuItem abc=new MenuItem(“New...”); // File.add(abc); File.add(new MenuItem(“New”)); File.add(new MenuItem(“Open”)); File.add(new MenuItem(“Save”)); File.add(new MenuItem(“Save As”)); File.add(new MenuItem(“-”)); File.add(new MenuItem(“PageSetup”)); File.add(new MenuItem(“Print”)); File.add(new MenuItem(“-”)); File.add(new MenuItem(“Exit”)); Edit.add(new MenuItem(“Undo”)); Edit.add(new MenuItem(“-”)); Edit.add(new MenuItem(“Cut”)); Edit.add(new MenuItem(“Copy”)); Edit.add(new MenuItem(“Paste”)); bar.add(File); bar.add(Edit); my_frm.setMenuBar(bar); my_frm.resize(300,300); my_frm.show();
- 72. 72 } } Þï¢î ¹«ó£è¤ó£ñ¤ô¢ menu -õ¤¬ù âõ¢õ£Á à¼õ£è¢°õ¶ âù¢Á ð£ó¢è¢èô£ñ¢. ºîô¤ô¢ ï£ñ¢ å¼ frame -¬ù à¼õ£è¢è «õí¢´ñ¢. ãªùù¤ô¢ frame -ô¢ î£ù¢ menu õó «õí¢´ñ¢ Üô¢ôõ£? Üîø¢è¢è£è my_frm âù¢ø ªðòó¤ô¢frame à¼õ£è¢èð¢ð좮¼è¢è¤ù¢ø¶. ܴ MenuBar bar = new MenuBar( ); âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þï¢î MenuBar Class ù¢ Íôñ¢ î£ù¢ ïñ¢ frame ù¢ à÷¢ menu -õ¤¬ù à¼õ£è¢è Þò½ñ¢. Þï¢î MenuBar - ø¤ù¤ô¢ ïñ袰 «î¬õò£ù Menu -è¬÷ à¼õ£è¢è Menu âù¢Áñ¢ èì¢ì¬÷ò¤¬ù ðòù¢ð´î¢îô£ñ¢. Menu File = new Menu (‘File’); Menu File = new Menu (‘Edit’); Þ颰 File, Edit âù¢Á Þóí¢´ menu-è÷¢ à¼õ£è¢èð¢ð좮¼è¢è¤ù¢øù. Menu õ¤ø¢è¢°÷¢ õó«õí¢®òù âù¢ù âù¢Á ªê£ô¢õîø¢è¢è£è menu Item âù¢ªø£¼ class Þ¼è¢è¤ù¢ø¶. Þî¬ùð¢ ðòù¢ð´î¢î¤ Menu õ¤ø¢° «õí¢®ò Item è¬÷ à¼õ£è¢è¤è¢ ªè£÷¢÷ô£ñ¢. File.add(new MenuItem(‘New’); âù¢ø º¬øò¤ô¢ MenuItem-è¬÷ à¼õ£è¢è¤è¢ ªè£÷¢÷ô£ñ¢. Þ¼î¤ò£è ïñ¢º¬ìò Menu-è¬÷ MenuBar object-´ìù¢ Þ¬íè¢è «õí¢´ñ¢ âù¢ðîø¢è¢è£è bar.add(File); bar.add(Edit); ܴ Þï¢î MenuBar-¬ù ïñ¢º¬ìò frame-ù¢ à÷¢ set ªêò¢ò «õí¢´ñ¢ âù¢ðîø¢è¢è£è my.frm.setMenuBar(bar); âù¢ø èì¢ì¬÷¬òð¢ ðòù¢ð´î¢¶è¤ù¢«ø£ñ¢. è¬ìê¤ò¤ô¢ frame -¬ù Display ªêò¢¶ ªè£÷¢è¤ù¢«ø£ñ¢.
- 74. 74 Üî¢î¤ò£òñ¢Üî¢î¤ò£òñ¢Üî¢î¤ò£òñ¢Üî¢î¤ò£òñ¢Üî¢î¤ò£òñ¢ 4. JavaDraw å¼ º¿¬ñò£ùå¼ º¿¬ñò£ùå¼ º¿¬ñò£ùå¼ º¿¬ñò£ùå¼ º¿¬ñò£ù Drawing ¹«ó£è¤ó£ñ¢¹«ó£è¤ó£ñ¢¹«ó£è¤ó£ñ¢¹«ó£è¤ó£ñ¢¹«ó£è¤ó£ñ¢ awt-ò¤ô¢ à÷¢÷ ªð¼ñ¢ð£ù¢¬ñò£ù Class object-è¬÷è¢ ªè£í¢´ å¼ º¿¬ñò£ù Drawing ¹«ó£è¤ó£ñ¢ Þ颰 õ¤÷è¢èð¢ð´è¤ù¢ø¶. Þ¶ Applet Ýè¾ñ¢ Ü«î êñòî¢î¤ô¢ Application ¹«ó£è¤ó£ñ£è¾ñ¢ â¿îð¢ð좴÷¢÷î£ô¢ å«ó êñòî¢î¤ô¢ Þóí¢´ õ¬èè÷¤½ñ¢ ðòù¢ð´î¢î¤è¢ ªè£÷¢÷ô£ñ¢. Þ¶ å¼ º¿¬ñò£ù ¹«ó£è¤ó£ñ£è Þ¼ð¢ðî£ô¢ Þîù¢ Þòè¢èî Üø¤ï¢¶ ªè£í¢ìð¤ø° ïñ¢ñ£ô¢ ªðó¤ò ¹«ó£è¤ó£ñ¢è¬÷ â¿î Þò½ñ¢. Þï¢î ¹«ó£è¤ó£ñ¤ô¢ Line, Circle, Box ºîô£ù õ®õé¢è÷¤ô¢ ⶠ«õí¢´«ñ£ Üî¬ù ªîó¤¾ ªêò¢¶ «õí¢®ò èôó¢è÷¤ô¢ õ¬óòô£ñ¢. Üî£õ¶ 覫ö ªè£´è¢èð¢ ð좴÷¢÷ ðìî¢î¤ô¢ à÷¢÷¶ «ð£ô¢ Þò颰ñ¢. ðì‹ðì‹ðì‹ðì‹ðì‹ 4.1 Þï¢î ¹«ó£è¤ó£ñ¢ å«ó File Ýè â¿îð¢ðìõ¤ô¢¬ô. ñ£ø£è ä îù¤î¢îù¤ Java ¹«ó£è¤ó£ñ¢è÷£è â¿îð¢ð좴÷¢÷ù ܬõ WidgetPanel.java JavaDrawFrame.java JavaDraw.java Shape.java UltraColor.java
- 75. 75 覫ö ªè£´è¢èð¢ð좴÷¢÷ Þï¢î file-è÷¤ù¢ Source File-è¬÷ Þ颰 ªè£´è¢èð¢ð좴÷¢÷õ£«ø Type ªêò¢¶ Save ªêò¢î ð¤ù¢ îù¤î¢îù¤ò£è Compile ªêò¢»é¢è÷¢. WidgetPanel.java import java.awt.*; import java.awt.event.*; import java.awt.Image; import java.applet.*; import java.net.*; import Shape.*; class WidgetPanel extends Panel { private final String AboutButtonName=”About...”, ClearButtonName=”CLEAR!”; protected boolean About_Mode=false; protected Choice shapeChoice=null, colorChoice=null; private Checkbox fillCheckbox=null, threeDCheckbox=null; private final static int _WIDTH=400,_HEIGHT=60; private int width=0,height=0; public WidgetPanel() { this(0,0); } public WidgetPanel(int width,int height) { setSize(width,height); new Panel(); setBackground(Color.lightGray);
- 76. 76 Button b=new Button(AboutButtonName); b.addActionListener(new ActionHandler() { public void actionPerformed(ActionEvent e) { super.actionPerformed(e); WidgetPanel.this.about(); } }); add(b); b=new Button(ClearButtonName); b.addActionListener(new ActionHandler() { public void actionPerformed(ActionEvent e) { super.actionPerformed(e); WidgetPanel.this.clearDrawCanvas(); } }); add(b); add(new Label(“Shape:”)); shapeChoice=new Choice(); shapeChoice.addItem(“Line”); shapeChoice.addItem(“Rectangle”); shapeChoice.addItem(“Oval”); shapeChoice.addItem(“Polygon”); shapeChoice.addItem(“Arc”); shapeChoice.addItem(“Text”); shapeChoice.addItem(“Image”); add(shapeChoice); add(new Label(“Color:”)); colorChoice=new Choice(); colorChoice.addItem(“Black”);
- 77. 77 colorChoice.addItem(“Blue”); colorChoice.addItem(“Cyan”); colorChoice.addItem(“DarkGray”); colorChoice.addItem(“Gray”); colorChoice.addItem(“Green”); colorChoice.addItem(“Light”); colorChoice.addItem(“Magenta”); colorChoice.addItem(“Orange”); colorChoice.addItem(“Pink”); colorChoice.addItem(“Red”); colorChoice.addItem(“White”); colorChoice.addItem(“Yellow”); colorChoice.addItemListener(new ItemListener() { public void itemStateChanged(ItemEvent e) { String colorStr=WidgetPanel.this. colorChoice.getSelectedItem(); WidgetPanel.this.getParent(). setForeground(UltraColor. stringColor(colorStr)); WidgetPanel.this.repaint(); } }); add(colorChoice); fillCheckbox=new Checkbox(“Fill”); add(fillCheckbox); threeDCheckbox=new Checkbox(“3D”); add(threeDCheckbox); } public Dimension getPreferredSize() {
- 78. 78 return new Dimension(width,height); } public void setSize(int width,int height) { if(width >0) this.width=width; else this.width=_WIDTH; if(height >0) this.height=height; else this.height=_HEIGHT; } public void clearDrawCanvas() { Graphics g=getParent().getGraphics(); int w=getParent().getSize().width, h=getParent().getSize().height; g.clearRect(0,0,w,h); } public void about() { About_Mode=true; clearDrawCanvas(); Color fg=getParent().getForeground(); getParent().setForeground(Color.black); Graphics g=getParent().getGraphics(); g.drawString(“JavaDraw!”,10,70); g.drawString(“by Aaron E.Walsh”,10,80); g.drawString(“version 1.0”,10,90); g.drawString(“revised 7.26.97”,10,100);
- 79. 79 getParent().setForeground(fg); } class ActionHandler implements ActionListener { public void actionPerformed(ActionEvent e) { if(About_Mode) { WidgetPanel.this.clearDrawCanvas(); WidgetPanel.this.About_Mode=false; } } } public void paint(Graphics g) { for(int yOffset=0 ; yOffset<5 ; yOffset++) { g.drawLine(0, getSize().height-yOffset, getSize().width, getSize().height-yOffset); } } public int getShape() { return shapeChoice.getSelectedIndex(); } public boolean isFilled() { return fillCheckbox.getState(); }
- 80. 80 public boolean isThreeD() { return threeDCheckbox.getState(); } } JavaDrawFrame.java import java.awt.*; import java.awt.event.*; class JavaDrawFrame extends Frame { public JavaDrawFrame(String str) { super(str); addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent e) { dispose(); System.exit(0); } }); } } JavaDraw.java import java.applet.*; import java.awt.*; import java.awt.event.*; import JavaDrawFrame;
- 81. 81 import WidgetPanel; import Shape; public class JavaDraw extends Applet { boolean m_fStandAlone=false; private WidgetPanel guiPanel=null; private int oldX=0,oldY=0; private Image theImage=null; private String imagePath=”tiger1.jpg”; private String m_foregroundColor=null; private String m_backgroundColor=null; private final String PARAM_forecolor=”forecolor”; private final String PARAM_backcolor=”backcolor”; String GetParameter(String strName,String args[]) { if(args==null) { return getParameter(strName); } int i; String strArg=strName + “=”; String strValue=null; for(i=0;i<args.length;i++) { if(strArg.equalsIgnoreCase (args[i].substring(0,strArg.length()))) { strValue=args[i].substring(strArg.length()); if(strValue.startsWith(“””)) { strValue=strValue.substring(1); if(strValue.endsWith(“””)) strValue=strValue.substring Java-11
- 82. 82 (0,strValue.length()-1); } } } return strValue; } void GetParameter(String args[]) { String param; param=GetParameter(PARAM_forecolor,args); if(param!=null) m_foregroundColor=param; param=GetParameter(PARAM_backcolor,args); if(param!=null) m_backgroundColor=param; } public static void main(String args[]) { JavaDrawFrame frame=new JavaDrawFrame(“JavaDraw!”); frame.show(); frame.setVisible(false); frame.setSize(frame.getInsets().left+ frame.getInsets().right+400,frame.getInsets().top+ frame.getInsets().bottom+350); JavaDraw applet_JavaDraw=new JavaDraw(); frame.add(“Center”,applet_JavaDraw); applet_JavaDraw.m_fStandAlone=true; applet_JavaDraw.GetParameter(args); applet_JavaDraw.init(); frame.show(); }
- 83. 83 public JavaDraw() { } public String getAppletInfo() { return “Name:JavaDrawrn”+ “Author: Packia Nathanrn”; } public String[][]getParameterInfo() { String[][]info= { { PARAM_forecolor,”String”,”Specifies default fore- ground color of this program(must be color class variable)”}, { PARAM_backcolor,”String”,”Specifies default background color of this program(must be a color class variable)”}, }; return info; } public void init() { if(!m_fStandAlone) GetParameter(null); resize(400,350); this.setLayout(new BorderLayout()); setBackground(Color.white); guiPanel=new WidgetPanel(); add(“North”,guiPanel); addMouseListener(getMouseListener()); addMouseMotionListener(getMouseMotionListener()); } MouseListener getMouseListener()
- 84. 84 { return new MouseAdapter() { public void mousePressed(MouseEvent e) { oldX=e.getX(); oldY=e.getY(); } }; } MouseMotionListener getMouseMotionListener() { return new MouseMotionAdapter() { public void mouseDragged(MouseEvent e) { JavaDraw.this.draw(e.getX(),e.getY()); } }; } void draw(int x,int y) { Graphics g=getGraphics(); boolean fill=guiPanel.isFilled(), threeD=guiPanel.isThreeD(); switch (guiPanel.getShape()) { case Shape.LINE: g.drawLine(oldX,oldY,x,y); break; case Shape.RECT: if(fill)
- 85. 85 { if(threeD) g.fill3DRect(oldX,oldY,x,y,true); else g.fillRect(oldX,oldY,x,y); }else{ if (threeD) g.draw3DRect (oldX+1,oldY+1,x+1,y+1,true); else g.drawRect(oldX,oldY,x,y); } break; case Shape.OVAL: if(fill) { g.fillOval(oldX,oldY,x,y); }else{ g.drawOval(oldX,oldY,x,y); } break; case Shape.ARC: if (fill) { g.fillArc(oldX,oldY,100,100,x,y); }else{ g.drawArc(oldX,oldY,100,100,x,y); } break; case Shape.POLY: int xCoords[]= {x+oldX,x+55,x+65,x+80,x+80,x+oldX}; int yCoords[]= {y+oldY,y+38,y+55,y+30,y+75,y+oldY}; Polygon thePoly=new
- 86. 86 Polygon(xCoords,yCoords,xCoords.length); if(fill) { g.fillPolygon(thePoly); }else{ g.drawPolygon(thePoly); } break; case Shape.TEXT: g.setFont(new Font (“Courier”,Font.BOLD,y/6)); g.drawString(“JavaDraw!”,x,y); break; case Shape.IMAGE: if (theImage==null) if(m_fStandAlone) { theImage=Toolkit. getDefaultToolkit().getImage(imagePath); }else{ theImage=getImage (getCodeBase(),imagePath); } int h=theImage.getHeight(this); int w=theImage.getWidth(this); if(fill) { g.drawImage (theImage,x-(w/2),y-(h/2), getForeground(),this); }else{ g.drawImage (theImage,x-(w/2),y-(h/2),this); } break;
- 87. 87 default: break; } g.dispose(); oldX=x; oldY=y; } } Shape.java public final class Shape { public final static int LINE=0, RECT=1, OVAL=2, POLY=3, ARC=4, TEXT=5, IMAGE=6; private Shape() { } } UltraColor.java import java.awt.*; public class UltraColor { private UltraColor() { } public static Color stringColor(String colorStr) {
- 88. 88 Color theColor=null; if(colorStr.equalsIgnoreCase(“black”)) { theColor=Color.black; }else if(colorStr.equalsIgnoreCase(“blue”)) { theColor=Color.blue; }else if(colorStr.equalsIgnoreCase(“cyan”)) { theColor=Color.cyan; }else if(colorStr.equalsIgnoreCase(“darkGray”)) { theColor=Color.darkGray; }else if(colorStr.equalsIgnoreCase(“gray”)) { theColor=Color.gray; }else if(colorStr.equalsIgnoreCase(“green”)) { theColor=Color.green; }else if(colorStr.equalsIgnoreCase(“lightGray”)) { theColor=Color.lightGray; }else if(colorStr.equalsIgnoreCase(“magenta”)) { theColor=Color.magenta; }else if(colorStr.equalsIgnoreCase(“orange”)) { theColor=Color.orange; }else if(colorStr.equalsIgnoreCase(“pink”)) { theColor=Color.pink; }else if(colorStr.equalsIgnoreCase(“red”)) { theColor=Color.red;
- 89. 89 }else if(colorStr.equalsIgnoreCase(“white”)) { theColor=Color.white; }else if(colorStr.equalsIgnoreCase(“yellow”)) { theColor=Color.yellow; }else { System.out.println(“No COLOR MATCH”); } return theColor; } } ºîô¤ô¢ Shape.java âÂñ¢ file-ô¤ô¢ âù¢ù â¿îð¢ð좮¼è¢è¤ù¢ø¶ âù¢ðî¬ùè¢ è£í¢«ð£ñ¢. Þî¤ô¢ Shape âù¢Âñ¢ class à¼õ£è¢èð¢ð좴 Üî¤ô¢ LINE, RECT, OVAL, POLY, ARC, TEXT, IMAGE âù¢ø Variable-è÷¢ Define ªêò¢òð¢ð좴 Üõø¢ø¤ô¢ õó¤¬êò£è 0,1,2, âù¢ø ñî¤ð¢¹è÷¢ ðî¤òð¢ ð좮¼è¢è¤ù¢øù. Þõø¢¬ø ï£ñ¢ WidgetPanel âù¢Âñ¢ Class-ô¢ ðòù¢ð´î¢î¤è¢ ªè£÷¢è¤ù¢«ø£ñ¢. ܴ UltraColor.java âù¢Âñ¢ file-ô¢ âù¢ù â¿îð¢ð좮¼è¢è¤ù¢ø¶ âù¢ðî¬ùè¢ è£í¢«ð£ñ¢. Þî¤ô¢ UltraColor âù¢Âñ¢ class åù¢Á â¿îð¢ð좴 ÜîÂ÷¢ StringColor âù¢ªø£¼ method â¿îð¢ð좮¼è¢è¤ù¢ø¶. Þîù¢ Parameter Ýè String Variable åù¢Áñ¢ return data type Ýè Color âù¢Âñ¢ class-ñ¢ ªè£´è¢èð¢ð좮¼è¢è¤ù¢ø¶. ï£ñ¢ Þï¢î function-ù¤ù¢ Parameter-ô¢ âù¢ù Color «õí¢´ñ¢ âù¢Á ªè£´ð¢«ð£ñ£ù£ô¢ Üï¢î Color-¬ù ªðø¢Áè¢ ªè£÷¢÷ô£ñ¢. Üî£õ¶ Java- õ¤ô¢ èôó¢è¬÷ ¬èò£÷¢õîø¢è¢ªèù¢Á îù¤ò£è Color âù¢ªø£¼ class à÷¢÷¶. Þï¢î Class-ù¢ object-®ø¢è¢°÷¢ ïñ袰 «î¬õò£ù èôó¤¬ù ðî¤ï¢¶ ¬õî¢¶è¢ ªè£í¢´ Üõø¢¬ø «õí¢®ò Þìî¢î¤ô¢ ðòù¢ð´î¢î¤è¢ ªè£÷¢÷ô£ñ¢. Color.black, Color.blue, Color.cyan âù¢ø õ¬èò¤ô¢ èôó¢è÷¤¬ùð¢ ðòù¢ð´î¢î¤è¢ ªè£÷¢÷ô£ñ¢. Þõø¢¬ø ï£ñ¢ WidgetPanel ¹«ó£è¤ó£ñ¤ô¢ ðòù¢ð´î¢î¤è¢ ªè£÷¢Àè¤ù¢«ø£ñ¢. ܴ WidgetPanel.java-õ¤ô¢ âù¢ù â¿îð¢ð좮¼è¢è¤ù¢ø¶ âùè¢ Java-12
- 90. 90 è£í¢«ð£ñ¢. Þï¢î file-ô¢ î£ù¢ WidgetPanel âù¢ªø£¼ class â¿îð¢ð좮¼è¢è¤ù¢ø¶. Þ¶ Panel class-ô¢ ޼ Inheritance ªêò¢òð¢ ð좮¼è¢è¤ù¢ø¶. âù«õ Þï¢î class-ø¢° object à¼õ£è¢°ñ¢ ªð£¿¶ î£ù£è«õ ïñ袰 Panel à¼õ£è¤õ¤´è¤ù¢ø¶. Þï¢î Panel-ô¤ô¢ î£ù¢ ïñ¢º¬ìò ¹«ó£è¤ó£ñ¤ø¢°î¢ «î¬õò£ù object-è÷¢ Üî£õ¶ Label, Choice, Checkbox ºîô£ù ܬùñ¢ ðî¤òð¢ð좮¼è¢è¤ù¢øù.Þ颰 ºîô¤ô¢ AboutButtonName ClearButtonName âù¢Á Þóí¢´ String °è÷¢ Define ªêò¢òð¢ð좮¼è¢è¤ù¢øù. ܴ About_mode âù¢Âñ¢ Boolean Variable à¼õ£è¢èð¢ð좴 Üî¤ô¢ False âù¢Âñ¢ ñî¤ð¢¹ ðî¤òð¢ð좮¼è¢è¤ù¢ø¶. ܴ ShapeChoice ñø¢Áñ¢ ColorChoice âù¢Âñ¢ Þóí¢´ Choice Class ù¢ object-è÷¢ Define ªêò¢òð¢ð좮¼è¢è¤ù¢øù. ð¤ù¢ùó¢ fillCheckbox, threeDCheckbox, âù¢Á Þóí¢´ Checkbox-è÷¢ define ªêò¢òð¢ð좮¼è¢è¤ù¢øù. ܴ _WIDTH, _HEIGHT, width, height âù¢Á int variable-è÷¢ à¼õ£è¢èð¢ð좴 Üõø¢ø¤ô¢ ñî¤ð¢¹è÷¢ ðî¤òð¢ð좮¼è¢è¤ù¢øù. Þï¢î class-ô¢ Þóí¢´ Constructor function-è÷¢ à÷¢÷ù. ºîô£õ¶ âï¢î ñî¤ð¢¹èÀñ¢ ªè£´è¢èð¢ ðìõ¤ô¢¬ôªòù¤ô¢ Þò颰è¤ù¢ø¶. Þóí¢ì£õ¶ Ýù¶ Height ñø¢Áñ¢ Width ªè£´ð¢ð¤ù¢ Üï¢î ñî¤ð¢ð¤¬ù ªè£í¢´ Þò颰è¤ù¢ø¶. WidgetPanel Constructor function-ô¢ ºîô¤ô¢ setSize(Width, Height) âù¢ø function ðòù¢ð´î¢îð¢ð좴÷¢÷¶. ï£ñ¢ ªè£´è¢è¤ù¢ø Width, Height ñî¤ð¢¹è÷¤ô¢ Panel Ýù¶ Set Ý°ñ¢. ܴ new Panel( ); âù¢Á ªè£´î¢î¤¼èè¢è¤ù¢«ø£ñ¢ Üô¢ôõ£? Üð¢ªð£¿¶î£ù¢ Panel Ýù¶ à¼õ£°ñ¢. ð¤ù¢ùó¢ SetBackground(Color.lightgray); âù¢ø function ðòù¢ð´î¢îð¢ð좴 Üîù¢Íôñ¢ Panel-ø¢è¢° Background Color Set ªêò¢òð¢ð좮¼è¢è¤ù¢øù. ð¤ù¢ùó¢ Button b = new Button (AboutButtonName); ..... add(b); âù¢Á About Button à¼õ £è¢èð¢ð좴 Üî¬ù Click ªêò¢î£ô¢ about( ) âù¢Âñ¢ function Þòé¢è «õí¢´ñ¢ âù¢Á ActionListener- ô¢ ªê£ô¢ôð¢ð좴÷¢÷¶. Þ¬îð¢«ð£ô«õ Clear Button Âñ¢ à¼õ£è¢èð¢ð좴 Üî¬ù Click ªêò¢î£ô¢ ClearDrawCanvas âù¢ø function Þòé¢è«õí¢´ñ¢ âù¢Á ActionListener-ô¢
- 91. 91 ªê£ô¢ôð¢ð좴÷¢÷¶. ܴ Shape: âù¢Âñ¢ Caption ù¤¬ùè¢ ªè£í¢ì Label åù¢Á à¼õ£è¢èð¢ð좴, Üî¬ùî¢ ªî£ìó¢ï¢¶ ShapeChoice âù¢Âñ¢ Choice à¼õ£è¢èð¢ ð´è¤ù¢ø¶. Þï¢î Choice-ô¢ Line, Rectangle, Oval, Polygon, Arc, Text, Image âù¢Âñ¢ Item-è÷¢ add ªêò¢òð¢ð´è¤ù¢øù. Þ¶ð¢«ð£ô«õ ColorChoice âù¢Áñ¢ Choice object åù¢Á à¼õ£è¢èð¢ð좴 Üñ¢ õó¤¬êò£è èôó¢è÷¤ù¢ ªðòó¢è÷¢ add ªêò¢òð¢ð´è¤ù¢øù. Þï¢î ColorChoice Ýù¶ ItemListener Event -ø¢°÷¢÷£èð¢ð좴 Þî¬ù Click ªêò¢»ñ¢ ªð£¿¶ âï¢î Color-ø¤¬ù ªîó¤¾ ªêò¢è¤ù¢«ø£«ñ£ Üîø¢° î°ï¢î color ø¤¬ù Ultracolor âù¢ø, ï£ñ¢ ãø¢è¢èù«õ «õÁ å¼ file-ô¢ â¿î¤ ¬õî¢î¤¼ï¢î class- ù¢ à÷¢÷¤¼ï¢¶ «õí¢®ò Color-ø¤¬ù𢠪ðø¢Áî¢î¼è¤ù¢ø¶. Üï¢î Color Ýù¶ ïñ¶ Panel-ù¢ foreground color Ýè set ªêò¢òð¢ð´è¤ù¢ø¶. ܴ fill ñø¢Áñ¢ 3D Ýè¤ò Þóí¢´ CheckBox-è÷¢ à¼õ£è¢èð¢ð좴 add ªêò¢òð¢ð좮¼è¢è¤ù¢øù. ClearDrawCanvas âù¢ªø£¼ function â¿îð¢ð좮¼ð¢ ð¬îè¢ èõù¤»é¢è÷¢. Þ¶ Þò颰ñ¢ ªð£¿¶ ïñ¶ JavaDraw Application -ô¢ õ¬óï¢î ðìé¢è÷¢ âô¢ô£ñ¢ Üö¤è¢èð¢ð´è¤ù¢ø¶. ܬî𢠫ð£ô«õ about( ) function Þò颰ñ¢ ªð£¿¶ ïñ¶ Application-¬ùð¢ ðø¢ø¤ò îèõô¢è÷¢ ªîó¤»ñ¢ð®è¢° ªêò¢òð¢ð좴÷¢÷¶. paint( ) function Ýù¶ âð¢ªð£¿ªîô¢ô£ñ¢ ¹«ó£è¤ó£ñ¤¬ù refresh ªêò¢è¤ù¢«ø£«ñ£ Üð¢ªð£¿ªîô¢ô£ñ¢ Þò颰ñ¢ âù¢Á ªîó¤»ñ¢. ܬîð¢«ð£ô«õ repaint( ) âù¢Á âð¢ªð£¿ªîô¢ô£ñ¢ ªè£´è¢è¤ù¢«ø£«ñ£ Üð¢ªð£¿¶ñ¢ Þò颰ñ¢. ïñ¶ Panel -ø¢è¢° 覫ö ê¤ø¤ò õó¤è÷¤ô¢ îø¢ªð£¿¶ âï¢î color, foreground Ýè Select ªêò¢òð¢ð좮¼è¢è¤ù¢ø¶ âù¢ðî¬ùê¢ ªê£ô¢õîø¢è¢è£èð¢ ðòù¢ð´ è¤ù¢ø¶. getShape, isfilled, isThreeD Ýè¤ò function -è¬÷ Þò袰ñ¢ªð£¿¶ º¬ø«ò Shape, fill, 3D Ýè¤ò Object-è÷¤ù¢ îø¢«ð£¬îò 郎ôò¤¬ù𢠪ðø¢Áè¢ ªè£÷¢÷ º®è¤ù¢ø¶. Þù¤ JavaDrawFrame.java âù¢Áñ¢ file-ô¢ âù¢ù â¿îð¢ð좮¼è¢è¤ù¢ø¶ âù¢ðî¬ùè¢è£íô£ñ¢. Þî¤ô¢ JavaDrawFrame âù¢Âñ¢ Class åù¢Á â¿îð¢ ð좮¼è¢è¤ù¢ø¶. Þ¶ Frame âÂñ¢ Class-ô¢ ޼ extends ªêò¢òð¢ð좮¼ð ¢ðî£ô¢ Þï¢î Class -ø¢° object -¬ù à¼õ£è¢°ñ¢ ªð£¿¶ ïñ袰 Frame 褬ìè¢è¤ù¢ø¶. ÞîÂ÷¢ ï£ñ¢ WindowCloseing âù¢Âñ¢ Event-¬ù â¿î¤
- 92. 92 ò¤¼è¢è¤ù¢«ø£ñ¢. ãªùù¤ô¢ ï£ñ¢ Close Button -ù¤¬ù Click ªêò¢»ñ¢ ªð£¿¶ Application Ýù¶ Close Ýè «õí¢´ñ¢ Üô¢ôõ£? Üîø¢è¢è£èî¢î£ù¢. Þ¼î¤ò£è ï£ñ¢ JavaDraw.java âù¢Âñ¢ file-ô¢ âù¢ù â¿îð¢ð좮¼è¢ è¤ù¢ø¶ âù¢ðî¬ù è£í¢«ð£ñ¢. Þï¢î ¹«ó£è¤ó£«ñ ïñ¢º¬ìò project -®ù¢ ºè¢è¤òñ£ù ¹«ó£è¤ó£ñ¢ Ý°ñ¢. ãªùù¤ô¢ Þî¤ô¢ î£ù¢ main( ) function Þ¼è¢è¤ù¢ø¶. ܬîð¢«ð£ô«õ init ( ) function -Âñ¢ Þ¼è¢è¤ù¢ø¶. Þï¢î ¹«ó£è¤ó£ñ¤¬ù ï¦é¢è÷¢ Compile ªêò¢¶ Java JavaDraw âù¢Á ªè£´î¢¶ Þò袰ñ¢ªð£¿¶ main( ) function Þò颰è¤ù¢ø¶. Applet Ýè Þò颰ñ¢ ªð£¿¶ init ( ) function Þòé¢è Ýóñ¢ð¤è¢è¤ù¢ø¶. Þê¢êñòî¢î¤ô¢ main ( ) function Þò颰õî¤ô¢¬ô. Þð¢ªð£¿¶ main ( ) function ù¤¬ù è£Âé¢è÷¢. Üî¤ô¢ ºîô¤ô¢ JavaDrawFrame Frame=new JavaDrawFrame(‘JavaDraw!‘); âù¢Á ªè£´è¢èð¢ð좴 å¼ Frame à¼õ£è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þï¢î Frame-ù¢ «ñô¢ ïñ¢º¬ìò WidgetPanel-ñ¢ ñø¢Áñ¢ õ¬ó»ñ¢ Þìºñ¢ õó«õí¢´ñ¢. âù«õ JavaDraw applet_javadraw = new JavaDraw ( ); âù¢Á ªè£´î¢¶ ïñ¢º¬ìò JavaDraw Class -ø¢° å¼ Object-®¬ù à¼õ£è¢° è¤ù¢«ø£ñ¢. Þõ¢õ£Á ªè£´è¢°ñ¢ ªð£¿¶ JavaDraw Class-ù¢ Ýóñ¢ðî¢î¤ô¤¼ï¢¶ ï£ñ¢ à¼õ£è¢è¤ò Variable èÀñ¢ ñø¢Áñ¢ method èÀñ¢ applet_javadraw âÂñ¢ Object -®ù¢ à÷¢ õõ¤´ñ¢. Þï¢î Object ®¬ù ïñ¢º¬ìò Frame-ù¢ Center Align Ý°ñ¢ð®è¢° add ªêò¢è¤ù¢«ø£ñ¢. ܴ applet_javadraw.init( ); frame.Show( ); âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. frame.Show( ) ªêò¢õîø¢° ºù¢ init( ) function -ù¤¬ù Þò袰è¤ù¢«ø£ñ¢. init function ô¢ Applet -¬ù resize ªêò¢¶ õ¤ì¢´ BorderLayout-®ô¢ õ¼ñ¢ð® ܬñè¢è¤ù¢«ø£ñ¢. ܴ WidgetPanel( ) Class -ù¢ Object åù¢¬ø à¼õ£è¢è¤ Üî¬ù North ðè¢èî¢î¤ô¢ add ªêò¢è¤ù¢«ø£ñ¢. Mouse -¬ù Click ªêò¢¶ Drag ªêò¢»ñ¢ ªð£¿¶ õ¬óò«õí¢´ñ¢. ݬèò£ô¢
- 93. 93 addMouseListener(getMouseListener ( )); addMouseMotionListener(getMouseMotion Listener ( )); âù¢Á Þóí¢´ MouseListener-è¬÷ Þò袰è¤ù¢«ø£ñ¢. Þ¬õ º¬ø«ò âð¢ªð£¿ªîô¢ô£ñ¢ Mouse -¬ù Click ªêò¢è¤ù¢«ø£«ñ£ Üð¢ªð£¿ªîô¢ô£ñ¢ MousePressed âù¢Âñ¢ Event -¬ù»ñ¢, MouseReleased event ®¬ù»ñ¢ Ü«î«ð£ô¢ MouseDraged Event-¬ù»ñ¢ Þò袰è¤ù¢ø¶. ï£ñ¢ âð¢ªð£¿ªîô¢ô£ñ¢ mouse -¬ù Click ªêò¢è¤ù¢«ø£«ñ£ Üð¢ªð£¿¶ mousePressed Event Þò颰è¤ù¢ø¶. Üî¤ô¢ ï£ñ¢ âï¢î Þìî¢î¤ô¢ Click ªêò¢è¤ù¢ «ø£ñ¢ âù¢ø ñî¤ð¢ð¤¬ù e.getX( ) ñø¢Áñ¢ e.getY( ) Ýè¤ò function-è÷¤ù¢ õ£ò¤ô£è oldX, oldY Ýè¤ò variable-è÷¤ô¢ ðî¤ï¢¶ ¬õè¢è¤ù¢«ø£ñ¢. ܴ ï£ñ¢ mouse - ä Drag ªêò¢»ñ¢ ªð£¿¶ mouseDragged Event Þò颰è¤ù¢ø¶ Üî¤ô¢ îø¢ªð£¿¶ mouse Ýù¶ â颰 Þ¼è¢è¤ù¢ø¶ âù¢ðî¬ù e.getX( ) ñø¢Áñ¢ e.getY( ) Ýè¤ò function-è÷¤ù¢ Íôñ¢ ªðø¢Á JavaDraw.this.draw (e.getX( ), e.getY( ) ); âù¢Á ï£ñ¢ â¿î¤ò¤¼è¢è¤ù¢ø function -ù¤¬ù Þò袰è¤ù¢«ø£ñ¢. Þï¢î draw function-ô¢ î£ù¢ ï£ñ¢ ܬù à¼õé¢è¬÷»ñ¢ õ¬óõîø¢è¢°ø¤ò ¹«ó£è¤ó£ñ¤¬ù â¿î¤ò¤¼è¢è¤ù¢«ø£ñ¢. Draw Function ô¢ ºîô¤ô¢ Graphics g=getGraphics( ); âù¢Á ªè£´î¢¶ Graphics Class -ø¢° å¼ Object -®¬ù à¼õ£è¢è¤è¢ ªè£÷¢Àè¤ù¢«ø£ñ¢. Þï¢î Graphics Class -ô¢ î£ù¢ Line, Rectangle, Oval âù¢Á ܬù õ¤îñ£ù ðìé¢è¬÷»ñ¢ õ¬óõîø¢°ø¤ò function -è÷¢ Þ¼è¢è¤ù¢øù. ܴ boolean fill= guiPanel.isFilled( ), threeD= guiPanel.isThreeD( ); Ýè¤ò Fucntion -è÷¤¬ù Þòè¢è¤, WidgetPanel-ô¢ à÷¢÷ Þóí¢´ CheckBox-è÷¢ Tick ªêò¢òð¢ð좴÷¢÷ùõ£, Þô¢¬ôò£ âù¢ðî¬ù Üø¤è¤ù¢«ø£ñ¢. FillCheckBox Tick ªêò¢òð¢ð좮¼ï¢î£ô¢ õ¬óè¤ù¢ø ðìé¢è÷¤ô¢ Color Ýù¶ ï¤óð¢ðð¢ð좴 õ¼ñ£Á ¹«ó£è¤ó£ñ¢ â¿î¤ò¤¼è¢è¤ù¢«ø£ñ¢. ܬî𢠫ð£ô«õ threeDCheckBox click ªêò¢òð¢ð좮¼ï¢î£ô¢ õ¬óòð¢ð´ñ¢ ðìé¢è÷¤ô¢ 3D Effect -è÷¢ õ¼ñ¢ð® ¹«ó£è¤ó£ñ¢ â¿î¤ò¤¼è¢è¤ù¢«ø£ñ¢. switch(guiPanel.getShape()) âù¢Á switch Statement ªè£´è¢èð¢ð좮¼ð¢ ð¬îè¢ èõù¤»é¢è÷¢. ï£ñ¢ âï¢î Item î¢î¤¬ù, Shape âÂñ¢ Choice -ô¢ Select ªêò¢î¤¼è¢è¤ù¢«ø£«ñ£ Üîø¢è¢°ø¤ò number-¬ù getShape function î¼è¤ù¢ø¶. Üî¬ù ï£ñ¢ åõ¢ªõ£Á case Ýè êó¤ð£ó¢î¢¶ Line âù¢Á Þ¼ð¢ð¤ù¢ Line õ¬óõîø¢°ø¤ò function -ù¤¬ù»ñ¢ Rect âù¢Á ªè£´î¢î£ô¢ Rectangle
- 94. 94 õ¬óõîø¢è¢°ø¤ò ¹«ó£è¤ó£ñ¤¬ù»ñ¢ âù¢Á õó¤¬êò£è ܬù Option è÷¤ø¢°ñ¢ ¹«ó£è¤ó£ñ¢ â¿î¤ò¤¼è¢è¤ù¢«ø£ñ¢ Þ颰 ðòù¢ð´î¢îð¢ð´ñ¢ function è÷¤ô¢ oldX, oldY âù¢ð¶ ï£ñ¢ mouse -¬ù ºîô¤ô¢ â颰 Click ªêò¢«î£«ñ£ Üï¢î ñî¤ð¢¹ Ý°ñ¢. ñ£ø£è x, y âù¢ð¶ ï£ñ¢ îø¢ªð£¿¶ âï¢î Þìî¢î¤ô¢ Þ¼è¢è¤ù¢«ø£«ñ£ Üï¢î ñî¤ð¢¹ Ý°ñ¢ âù¢ðî¬ù 郎ùõ¤ô¢ ªè£÷¢Àé¢è÷¢. Þ¼î¤ò£è Mouse -¬ù Release ªêò¢»ñ¢ ªð£¿¶ Mouse Released function Þò颰è¤ù¢ø¶. Þî¤ô¢ Update(getGraphics( )) âù¢ø function-¬ù ðòù¢ð´î¢î¤ ò¤¼è¢è¤ù¢«ø£ñ¢. Þ¶ repaint( ) function-¬ù «ð£ô«õ paint function-¬ù Þò袰è¤ù¢ø¶.
- 95. 95 Üî¢î¤ò£òñ¢Üî¢î¤ò£òñ¢Üî¢î¤ò£òñ¢Üî¢î¤ò£òñ¢Üî¢î¤ò£òñ¢ 5. Swing - Java Foundation Classes (JFC) Þ¶õ¬ó ï£ñ¢ Abstract windowing ToolKit (awt) âÂñ¢ Package -ô¢ à÷¢÷ Class -è¬÷ð¢ ðòù¢ð´î¢î¤ ¹«ó£è¤ó£ñ¢è¬÷ â¿î¤ õî£ñ¢. Þï¢î awt Package-ô¢ à÷¢÷ Label, TextField, Choice, Button ºîô£ù Component -è¬÷𢠫ð£ù¢Á Þòé¢èè¢Ã®ò, Üî¬ùè¢ è£ì¢®½ñ¢ Üöè£è¾ñ¢, ê¤øð¢ð£è¾ñ¢ Þòé¢èé¢Ã®ò, ðô ôîô¢ Component -è¬÷»ñ¢ ªè£í¢ì ðô¢«õÁ Class è÷¤ù¢ ªî£°ð¢ð¤¬ùî¢î£ù¢ Üî£õ¶ Package ¬ùî¢î£ù¢ Java foundation Classes (JFC) âù¢Á ܬöè¢è¤ù¢«ø£ñ¢. Þî¬ù Swing âù¢Áñ¢ õöé¢èô£ñ¢. ê£îóíñ£è awt ò¤ô¢ TextField âù¢Á class Þ¼ð¢ð¤ù¢, Swing -ô¢ JTextField âù¢Á class ޼袰ñ¢. Üî£õ¶ Swing Package -ô¢ à÷¢÷ ܬù class - èÀñ¢ J âù¢ø â¿î¢î¤ô¢ Ýóñ¢ð¤è¢è¤ù¢øù. Þù¤ swing class -è¬÷ð¢ ðòù¢ð´î¢î¤ âõ¢õ£Á ¹«ó£è¤ó£ñ¢è¬÷ à¼õ£è¢°õ¶ âùè¢ è£íô£ñ¢. Listing 5.1 import javax.swing.*; import java.awt.*; public class swg1 extends JApplet { public void init() { JLabel lbl_name=new JLabel(“Name: “); JTextField txt_name=new JTextField(); JLabel lbl_age=new JLabel(“Age: “); JTextField txt_age=new JTextField(); GridLayout xyz=new GridLayout(2,2); getContentPane().setLayout(xyz);
- 96. 96 getContentPane().add(lbl_name); getContentPane().add(txt_name); getContentPane().add(lbl_age); getContentPane().add(txt_age); } } Swing è¤ô¢ à÷¢÷ component -è¬÷ð¢ ðòù¢ð´î¢î «õí¢´ñ£ù£ô¢ import javaX.swing.*; âù¢Á ªè£´î¢¶ Swing Package-¬ù ºîô¤ô¢ Import ªêò¢¶ ªè£÷¢÷ «õí¢´ñ¢. Þï¢î ¹«ó£è¤ó£ñ£ù¶ å¼ Applet Ý°ñ¢. public class swg1 extends JApplet âù¢Á ªè£´è¢èð¢ ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. JFC Component- è¬÷ð¢ ðòù¢ ð´î¢î¤ Applet â¿î «õí¢´ñ¢ âù¤ô¢ Þï¢î JApplet class -¬ùî¢î£ù¢ ðòù¢ ð´î¢î«õí¢´ñ¢. init ( ) function -ù¢ à÷¢ JLabel, JTextField Ýè¤ò class è¬÷ð¢ ðòù¢ð´î¢î¤ lbl_name, txt_name, lbl_age, txt_age ºîô¤ò Object-è÷¢ à¼õ£è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þ¬õ ê£î£óíñ£è awt Package-ô¢ ï£ñ¢ ðòù¢ð´î¢î¤ò º¬øò¤«ô«ò Þò颰ñ¢. Ýù£ô¢ Þõø¢ø¤ù¢ õ®õî¢î¤ô¢ ïô¢ô õ¤î¢î¤ò£êñ¢ ªîó¤»ñ¢. ܴ 2 Row ñø¢Áñ¢ 2 Column Ü÷¾è¬÷è¢ ªè£í¢ì GridLayout åù¢Á xyz âù¢Áñ¢ ªðòó¤ô¢ à¼õ£è¢èð¢ð좮¼è¢è¤ù¢ø¶. ð¤ù¢ùó¢ getContentPane( ).SetLayout(xyz); getContentPane( ).Add(lbl_name); âù¢ø õ¬èò¤ô¢ Object-è÷¢ add ªêò¢òð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þï¢î getContentPane( ) âù¢ð¶ Swing Component -è¬÷ ¬èò£÷¢õîø¢°è¢ªèù¢«ø Þ¼è¢èè¢ Ã®ò å¼ container Ý°ñ¢. ÞîÂ÷¢ î£ù¢ ï£ñ¢ ïñ¶ ܬù Swing object -è¬÷»ñ¢ add ªêò¢ò «õí¢´ñ¢ âù¢ðî¬ù 郎ùõ¤ô¢ ªè£÷¢Àé¢è÷¢. ¹«ó£è¤ó£ñ¤¬ù õöè¢èñ¢ «ð£ô¢ compile ªêò¢¶ å¼ HTML file-¬ù à¼õ£è¢è¤ appletviewer ø¤ù¤«ô£ Üô¢ô¶ Browser ø¤ù¤«ô£ Þòè¢è¤ð¢ ð£¼é¢è÷¢.
- 97. 97 ðì‹ðì‹ðì‹ðì‹ðì‹ 5.1 Listing 5.2 import javax.swing.*; import java.awt.*; public class swg2 { public static void main(String argv[]) { JFrame abc=new JFrame(“Hello”); JLabel lbl_name=new JLabel(“Name: “); JTextField txt_name=new JTextField(); JLabel lbl_age=new JLabel(“Age: “); JTextField txt_age=new JTextField(); GridLayout xyz=new GridLayout(2,2); abc.getContentPane().setLayout(xyz); abc.getContentPane().add(lbl_name); abc.getContentPane().add(txt_name); abc.getContentPane().add(lbl_age); abc.getContentPane().add(txt_age);
- 98. 98 abc.resize(200,100); abc.show(); } } Þï¢î ¹ó£è¤ó£ñ¢ å¼ Swing Application Ýè â¿îð¢ð좴÷¢÷¶. main( ) function -ù¤ù¢ à÷¢ JFrame abc=new JFrame(‘Hello’); âù¢Á ªè£´è¢èð¢ð좴 å¼ Swing à¼õ£è¢èð¢ð좮¼è¢è¤ù¢ø¶. ð¤ù¢ùó¢ JLabel ñø¢Áñ¢ JTextFieldÝè¤ò Class-è¬÷ð¢ ðòù¢ð´î¢î¤ lbl_name,txt_name,lbl_age,txt_ageÝè¤ò Object -è÷¢ à¼õ£è¢èð¢ð좮¼è¢è¤ù¢øù. Þî¬ùî¢ ªî£°î¢¶ 2,2âù¢ø Ü÷¾¬ìò GridLayout åù¢Á xyz âù¢Âñ¢ ªðòó¤ô¢ à¼õ£è¢èð¢ ð좮¼è¢è¤ù¢ø¶. ÞÁî¤ò¤ô¢ abc âù¢Âñ¢ Frame- ô¢ Object-è¬÷ ªð£¼î¢¶õîø¢è¢è£è abc.getContentPane( ).SetLayout(xyz); abc.getContentPane( ).Add(lbl_name); âù¢ø õ¬èò¤ô¢ Object -è÷¢ add ªêò¢òð¢ð´è¤ù¢øù. ÞÁî¤ò£è Frame Ýù¶ Show ªêò¢òð¢ð´è¤ù¢ø¶. Þï¢î𢠹«ó£è¤ó£ñ¤¬ù õöè¢èñ¢ «ð£ô¢ Compile ªêò¢¶ îava swg2 âù¢Á ªè£´î¢¶ Þòè¢è¤ð¢ ð£¼é¢è÷¢. ðì‹ðì‹ðì‹ðì‹ðì‹ 5.2
- 99. 99 Listing 5.3 import javax.swing.*; import java.awt.*; public class swg3 { public static void main(String arg[]) { JFrame abc=new JFrame(“Hello”); Icon i_one=new ImageIcon(“bullet1.gif”); Icon i_two=new ImageIcon(“bullet2.gif”); Icon i_three=new ImageIcon(“bullet3.gif”); Icon i_four=new ImageIcon(“bullet4.gif”); JButton but_one=new JButton(“One”,i_one); JButton but_two=new JButton(“Two”,i_two); JComboBox com_one=new JComboBox(); com_one.addItem(“Tamil Nadu”); com_one.addItem(“Andra Pradesh”); com_one.addItem(“Karnataka”); com_one.addItem(“Maharastra”); com_one.addItem(“Orisa”); JComboBox com_two=new JComboBox(); com_two.addItem(“India”); com_two.addItem(“Pakistan”); ButtonGroup sex=new ButtonGroup(); JRadioButton male=new JRadioButton(“Male”,i_three); JRadioButton female=new JRadioButton(“Female”,i_four); sex.add(male); sex.add(female);
- 100. 100 JCheckBox chk_one=new JCheckBox(“Tamil/English”); JCheckBox chk_two=new JCheckBox(“Computer/ Manual”); GridLayout xyz=new GridLayout(4,2); abc.getContentPane().setLayout(xyz); abc.getContentPane().add(but_one); abc.getContentPane().add(but_two); abc.getContentPane().add(com_one); abc.getContentPane().add(com_two); abc.getContentPane().add(male); abc.getContentPane().add(female); abc.getContentPane().add(chk_one); abc.getContentPane().add(chk_two); abc.resize(400,200); abc.show(); } } Þï¢î ¹«ó£è¤ó£ñ¤ô¢ Icon JButton, JComboBox, ButtonGroup, JRadioButton, JCheckBox Ýè¤ò Swing Class -è÷¢ õ¤÷è¢èð¢ð좴÷¢÷ù. Þî¤ô¢ Icon Class-ù¢ Object -è¬÷ð¢ ðòù¢ð´î¢î¤ Image file -è÷¤ù¢ gif, jpg, ico, tiff ºîô£ù File è÷¤ô¢ à÷¢÷ ðìé¢è¬÷ ðî¤ï¢¶ ¬õî¢¶è¢ ªè£÷¢÷ô£ñ¢. Þõø¢¬ø JButton, JCheckBox âù¢Á Swing Component ðôõø¢ø¤½ñ¢ ðòù¢ð´î¢î¤è¢ ªè£÷¢÷ô£ñ¢. JButton class Ýù¶ Push Button object -è¬÷ à¼õ£è¢°õîø¢°ð¢ ðòù¢ð´è¤ù¢ø¶. JComboBox class Ýù¶ ðô¢«õÁ Item -è¬÷ îù¢ùèî¢«î ªè£í¢ì Choice åù¢ø¤¬ù à¼õ£è¢èð¢ ðòù¢ð´è¤ù¢ø¶. awt -ò¤ô¢ Checkbox âù¢Âñ¢ å«ó èì¢ì¬÷¬òð¢ ðòù¢ð´î¢î¤ Radio Button ñø¢Áñ¢ Checkbox Ýè¤òõø¢¬ø à¼õ£è¢è¤«ù£ñ¢. Ýù£ô¢ Swing-ô¢ Radio Button-¬ù à¼õ£è¢°õîø¢è¢ªèù¢Á ButtonGroup ñø¢Áñ¢ JRadioButton âù¢Á Þóí¢´ class -è÷¢ Þ¼è¢è¤ù¢øù. Checkbox -ªèù¢Á îù¤ò£è JCheckBox âù¢ø class Þ¼è¢è¤ù¢ø¶. Þ颰 Object -è¬÷ à¼õ£è¢°ñ¢ êñòé¢è÷¤ô¢ Üõø¢ø¤ô¢ Icon - è¬÷ ªè£´î¢î¤¼ð¢ð¬îè¢ èõù¤»é¢è÷¢.
- 101. 101 ðì‹ðì‹ðì‹ðì‹ðì‹ 5.3 Listing 5.4 import javax.swing.*; import java.awt.*; public class toolbar extends JFrame { public static void main(String argv[]) { toolbar abc = new toolbar(); JMenuBar mymen = new JMenuBar(); JMenu file = new JMenu(“File”); JMenu edit = new JMenu(“Edit”); file.add(new JMenuItem(“New”)); file.add(new JMenuItem(“Open”)); file.add(new JMenuItem(“Close”)); edit.add(new JMenuItem(“Cut”));
- 102. 102 edit.add(new JMenuItem(“Copy”)); edit.add(new JMenuItem(“Paste”)); mymen.add(file); mymen.add(edit); abc.setJMenuBar(mymen); JToolBar krish=new JToolBar(); Icon ione = new ImageIcon (“bullet1.jpg”); Icon itwo = new ImageIcon (“bullet2.gif”); Icon ithree = new ImageIcon (“bullet3.gif”); Icon ifour = new ImageIcon (“bullet4.gif”); JButton one=new JButton(“One”,ione); JButton two=new JButton(“Two”,itwo); JButton three=new JButton(“Three”,ithree); JButton four=new JButton(“Four”,ifour); krish.add(one); krish.add(two); krish.add(three); krish.add(four); abc.getContentPane().add(krish); abc.setTitle(“Demo Program For Tool Bar”); abc.resize(300,300); abc.show(); } } Þï¢î ¹«ó£è¤ó£ñ¤ô¢ ï£ñ¢ Swing -º¬øò¤¬òð¢ ðòù¢ð´î¢î¤ Menu ñø¢Áñ¢ Toolbar Ýè¤òõø¢¬ø à¼õ£è¢è¤ò¤¼è¢è¤ù¢«ø£ñ¢. Þ¬õ å¼ Frame-ô¢ î£ù¢ õ¼ñ¢ âù¢ðî£ô¢ ºîô¤ô¢ abc âù¢Âñ¢ Frame -¬ù à¼õ£è¢è¤ò¤¼è¢è¤ù¢«ø£ñ¢.
- 103. 103 JMenubar class Ýù¶ menu bar-¬ù à¼õ£è¢°õîø¢°ð¢ ðòù¢ð´è¤ù¢ø¶. JMenu class -¬ùð¢ ðòù¢ð´î¢î¤ file, edit âù¢Á Þóí¢´ menu-è¬÷ à¼õ£è¢è¤ ò¤¼è¢è¤ù¢«ø£ñ¢. Þï¢î menu - è÷¤ô¢ JMenuItem class-¬ùð¢ ðòù¢ð´î¢î¤ menu èì¢ì¬÷è¬÷ menu bar à¼õ£è¢è¤ò¤¼è¢è¤ù¢«ø£ñ¢. Þ¼î¤ò£è menu-è¬÷ MenuBar àìÂñ¢, MenuBar -ø¤¬ù frame àìù¢ Þ¬íî¢î¤¼è¢è¤ù¢«ø£ñ¢. Toolbar-è¬÷ à¼õ£è¢°õîø¢° JToolBar âù¢Âñ¢ èì¢ì¬÷ ðòù¢ð´ è¤ù¢ø¶. Þîù¢ Íôñ¢ Toolbar-è¬÷ à¼õ£è¢è¤ ÜîÂìù¢ ï£ñ¢ îù¤ò£è Button Object-è¬÷ à¼õ£è¢è¤ Þ¬íè¢è «õí¢´ñ¢. Þï¢î Button è÷¤ô¢ ï£ñ¢ Icon- è¬÷ Þ¬íî¢î¤¼è¢è¤ù¢«ø£ñ¢ âù¢ð¬îè¢ èõù¤»é¢è÷¢. ðì‹ðì‹ðì‹ðì‹ðì‹ 5.4 Listing 5.5 import javax.swing.*; import java.awt.*; public class tabbed extends JFrame { Container d = getContentPane(); tabbed()
- 104. 104 { Icon one = new ImageIcon (“bullet1.gif”); Icon two = new ImageIcon (“bullet2.gif”); Icon three = new ImageIcon (“bullet3.gif”); JTabbedPane country = new JTabbedPane(); country.addTab(“India”,one,new india()); country.addTab(“Pakistan”,two,new pakistan()); country.addTab(“China”,three,new china()); d.add(country); } public static void main(String argv[]) { tabbed xyz = new tabbed(); xyz.setTitle(“Tabbed Demo”); xyz.resize(400,400); xyz.show(); } } class india extends JPanel { JLabel lbl_pre = new JLabel (“President : Mr. K.R. Narayanan”); JLabel lbl_pri = new JLabel (“Prime Minister : Mr. A.B. Vajpayee”); JLabel lbl_chi = new JLabel (“Chief Minister : Mr. M. Karunanidhi”); india() { setLayout(new FlowLayout(FlowLayout.LEFT,10,10)); add(lbl_pre); add(lbl_pri); add(lbl_chi);
- 105. 105 } } class pakistan extends JPanel { JLabel lbl_pre = new JLabel (“President : General. Parvees Musharaf”); pakistan() { setLayout(new FlowLayout(FlowLayout.LEFT,10,10)); add(lbl_pre); } } class china extends JPanel { JLabel lbl_pre = new JLabel (“President : Giang Gemin”); china() { setLayout(new FlowLayout (FlowLayout.LEFT,10,10)); add(lbl_pre); } } Þï¢î𢠹«ó£è¤ó£ñ¤ô¢ Tabbed Pane âù¢ø¬öè¢èð¢ð´ñ¢ Component-è÷¢ õ¤÷è¢èð¢ð좴÷¢÷ù. Þî¬ù ªè£í¢´ ðô ðè¢èé¢è¬÷è¢ ªè£í¢ì ܬñð¢ð¤¬ù à¼õ£è¢è Þò½ñ¢. public class tabbed extends JFrame âù¢Á ªè£´î¢¶ JFrameclassàìù¢inheritanceªêò¢òð¢ð좮¼ð¢ðî£ô¢ main()function-ô¢xyz âù¢ø Object à¼õ£°ñ¢ ªð£¿«î Frame -ñ¢ à¼õ£è¤õ¤´è¤ù¢ø¶ ñø¢Áñ¢ Constructor function-ñ¢ î£ù£è Þò颰è¤ù¢ø¶. Þï¢î Constructorfunction -ô¢ ï£ñ¢ one,two,three âù¢Á Íù¢Á IconObject-è¬÷bullet1.gif,bullet2.gif,bullet3.gif âù¢ø file -è¬÷è¢ ªè£í¢´
- 106. 106 à¼õ£è¢è¤ò¤¼è¢è¤ù¢«ø£ñ¢. ð¤ù¢ùó¢ JTabbedPane country= new JTabbedPane( ); âù¢Á ªè£´î¢¶ country âù¢Âñ¢ Object-®¬ù à¼õ£è¢è¤ò¤¼è¢è¤ù¢«ø£ñ¢. Þï¢î Object- ®ô¢ ï£ñ¢ ðô¢«õÁ tab ðè¢èé¢è¬÷ Þ¬íè¢è º®»ñ¢. Üï¢î ðè¢èé¢è÷¢ å¼ Panel Ýè Þ¼è¢è «õí¢´ñ¢. âù«õ ï£ñ¢ class india extends JPanel ........... class pakistan extends JPanel ........... class china extends JPanel ........... Ýè¤ò Class è¬÷ à¼õ£è¢è¤ Üõø¢ø¤ù¢ Object -è¬÷ country.add(‘India’,one,newindia()); country.add(‘Pakistan’, two, new pakistan( )); country.add(‘China’, three, new china( )); âù¢Á ªè£´î¢¶ à¼õ£è¢è¤ò¤¼è¢è¤ù¢«ø£ñ¢. ¹«ó£è¤ó£ñ¤ù¢ Ýóñ¢ðî¢î¤ô¢ container d= getContentPane( ) âù¢Á ªè£´î¢î¤¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þï¢î Container Object -è÷¢ getContentPane( ) âÂñ¢ Layout ®ô¢ ðî¤ï¢¶ ¬õî¢¶è¢ ªè£÷¢Àñ¢ î¤øù¢ ð¬ìî¢î¬õ. ï£ñ¢ d.add(country) âù¢Á ªè£´è¢°ñ¢ ªð£¿¶ àí¢¬ñò¤ô¢ ïñ袰 getContentPane( ) -ô¢ î£ù¢ ïñ¢º¬ìò Object -è÷¢ Align Ýè¤ù¢ø¶ âù¢ðî¬ù 郎ùõ¤ô¢ ªè£÷¢Àé¢è÷¢. ðì‹ðì‹ðì‹ðì‹ðì‹ 5.5
- 107. 107 Listing 5.6 import java.awt.*; import javax.swing.*; import javax.swing.tree.*; public class maram extends JFrame { maram() { Container x=getContentPane(); //********** DefaultMutableTreeNode country = new DefaultMutableTreeNode (“Country”); //********** DefaultMutableTreeNode india = new DefaultMutableTreeNode (“India”); DefaultMutableTreeNode pakistan = new DefaultMutableTreeNode (“Pakistan”); DefaultMutableTreeNode america = new DefaultMutableTreeNode (“America”); DefaultMutableTreeNode china = new DefaultMutableTreeNode (“China”); //*********** DefaultMutableTreeNode tamil = new DefaultMutableTreeNode (“Tamil”); DefaultMutableTreeNode andra= new DefaultMutableTreeNode (“Andra”); DefaultMutableTreeNode karnataka= new DefaultMutableTreeNode (“Karnataka”); DefaultMutableTreeNode bihar= new DefaultMutableTreeNode (“Bihar”);
- 108. 108 //*********** DefaultMutableTreeNode lahore = new DefaultMutableTreeNode (“Lahore”); DefaultMutableTreeNode karachi = new DefaultMutableTreeNode (“Karachi”); DefaultMutableTreeNode sindhu = new DefaultMutableTreeNode (“Sindhu”); //********** DefaultMutableTreeNode chennai = new DefaultMutableTreeNode (“Chennai”); DefaultMutableTreeNode madurai = new DefaultMutableTreeNode (“Madurai”); DefaultMutableTreeNode trichy = new DefaultMutableTreeNode (“Trichy”); country.add(india); country.add(pakistan); country.add(america); country.add(china); india.add(tamil); india.add(andra); india.add(karnataka); india.add(bihar); pakistan.add(lahore); pakistan.add(karachi); pakistan.add(bihar); tamil.add(chennai); tamil.add(madurai); tamil.add(trichy);
- 109. 109 JTree countrymaram = new JTree(country); x.add(countrymaram); } public static void main(String argv[]) { maram abc = new maram(); abc.setTitle(“Tree View Example”); abc.resize(400,400); abc.show(); } } Þï¢î ¹«ó£è¤ó£ñ¤ô¢ Treeview âù¢ø¬öè¢èð¢ð´ñ¢ Component-è÷¢ õ¤÷è¢èð¢ ð좴÷¢÷ù. Treeview âù¢ð¶ å¼ Item î¢î¤ø¢°÷¢ ñø¢ªø£Á Item âù¢Á åù¢øù¢ð¤ù¢ åù¢ø£è à÷¢«÷ ªêô¢½ñ¢ð® ޼袰ñ¢ ܬñ𢹠ݰñ¢. ðì‹ðì‹ðì‹ðì‹ðì‹ 5.6
- 110. 110 Treeview -¬ùð¢ ðòù¢ð´î¢î «õí¢´ñ¢ âù¤ô¢ javax.swing.tree.* âù¢Âñ¢ Package-¬ù import ªêò¢ò «õí¢´ñ¢. ãªùù¤ô¢ JTree ñø¢Áñ¢ DefaultMutableTreeNode ºîô£ù class -è÷¢ Þï¢î Package-ô¢î£ù¢ Þ¼è¢è¤ù¢øù. ïñ袰 JTreeView Component-®ù¢ à÷¢ âù¢ªùù¢ù Item-è÷¢ õó «õí¢´«ñ£ Üõø¢¬ø à¼õ£è¢°õîø¢è¢° DefaultmutableTreeNode èì¢ì¬÷ð¢ðòù¢ ð´è¤ù¢ø¶. Þî¬ùð¢ ðòù¢ð´î¢î¤ «î¬õò£ù Item è¬÷ à¼õ£è¢è¤òð¤ù¢ âîï¢î Item è÷¢ âîªùîù¢ à÷¢ õó«õí¢´ñ¢ âù¢ðî¬ùè¢ è¦«ö ªè£´è¢èð¢ ð좴÷¢÷¶ «ð£ô¢ ªè£´î¢¶ add ªêò¢¶ ªè£÷¢Àé¢è÷¢. country.add(india); country.add(pakistan); country.add(america); country.add(china); india.add(tamilnadu); ..... Þ¼î¤ò£è JTree countrymaran = new JTree(country); âù¢Á ªè£´î¢î¤¼ð¢ðîù¢ Íôñ¢ âï¢î Item Treeview õ¤ù¤ô¢ ºîô¤ô¢ õó«õí¢´ñ¢ âù¢Á Ãø¤ò¤¼è¢ è¤ù¢«ø£ñ¢. Üîù¢ð® country Ýù¶ countrymaran âÂñ¢ Object-®ô¢ Top Level Object Ýè õ¤÷颰è¤ù¢ø¶. Listing 5.7 import javax.swing.*; import javax.swing.table.*; import java.awt.event.WindowAdapter; import java.awt.event.WindowEvent; import java.awt.Dimension; public class Table { public Table() { JFrame frame = new JFrame(“Table”); frame.addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent e) {
- 111. 111 System.exit(0); } } ); // Take the dummy data from SwingSet. final String[] names = {“First Name”, “Last Name”, “Favorite Color”,“Favorite Number”, “Vegetarian”}; final Object[][] data = { {“Mark”, “Andrews”, “Red”, new Integer(2), new Boolean(true)}, {“Tom”, “Ball”, “Blue”, new Integer(99), new Boolean(false)}, {“Alan”, “Chung”, “Green”, new Integer(838), new Boolean(false)}, {“Jeff”, “Dinkins”, “Turquois”, new Integer(8), new Boolean(true)}, {“Amy”, “Fowler”, “Yellow”, new Integer(3), new Boolean(false)}, {“Brian”, “Gerhold”, “Green”, new Integer(0), new Boolean(false)}, {“James”, “Gosling”, “Pink”, new Integer(21), new Boolean(false)}, {“David”, “Karlton”, “Red”, new Integer(1), new Boolean(false)}, {“Dave”, “Kloba”, “Yellow”, new Integer(14), new Boolean(false)}, {“Peter”, “Korn”, “Purple”, new Integer(12), new Boolean(false)}, {“Phil”, “Milne”, “Purple”, new Integer(3), new Boolean(false)}, {“Dave”, “Moore”, “Green”, new Integer(88), new Boolean(false)}, {“Hans”, “Muller”, “Maroon”, new Integer(5), new Boolean(false)}, {“Rick”, “Levenson”, “Blue”, new Integer(2), new Boolean(false)}, {“Tim”, “Prinzing”, “Blue”, new Integer(22), new Boolean(false)}, {“Chester”, “Rose”, “Black”, new Integer(0), new
- 112. 112 Boolean(false)}, {“Ray”, “Ryan”, “Gray”, new Integer(77), new Boolean(false)}, {“Georges”, “Saab”, “Red”, new Integer(4), new Boolean(false)}, {“Willie”, “Walker”, “Phthalo Blue”, new Integer(4), new Boolean(false)}, {“Kathy”, “Walrath”, “Blue”, new Integer(8), new Boolean(false)}, {“Arnaud”, “Weber”, “Green”, new Integer(44), new Boolean(false)} }; // Create a model of the data. TableModel dataModel = new AbstractTableModel() { // These methods always need to be implemented. public int getColumnCount() { return names.length; } public int getRowCount() { return data.length;} public Object getValueAt(int row, int col) {return data[row][col]; } // The default implementations of these methods in // AbstractTableModel would work, but we can refine them. public String getColumnName(int column) {return names[column];} public Class getColumnClass(int col) {return getValueAt(0,col).getClass();} public boolean isCellEditable(int row, int col) {return (col==4);} public void setValueAt(Object aValue, int row, int column) { data[row][column] = aValue; }
- 113. 113 }; // Instead of making the table display the data as it would nor- mally with: // JTable tableView = new JTable(dataModel); // Add a sorter, by using the following three lines instead of the one above. JTable tableView = new JTable(dataModel); JScrollPane scrollpane = new JScrollPane(tableView); scrollpane.setPreferredSize(new Dimension(700, 300)); frame.getContentPane().add(scrollpane); frame.pack(); frame.setVisible(true); } public static void main(String[] args) { new Table(); } } Þï¢î ¹«ó£è¤ó£ñ¤ô¢ table âù¢ø¬öè¢èð¢ð´ñ¢ Component õ¤÷è¢èð¢ ð좴÷¢÷¶. table -è÷¤ô¢ ïñ¢ñ£ô¢ Record-è¬÷ display ªêò¢¶ ªè£÷¢÷ º®»ñ£îô£ô¢ Þîù¢ ðòù¢ð£´ Þù¢ø¤ò¬ñò£îî£è¤ø¶.Table Component-®¬ù ï£ñ¢ ðòù¢ð´î¢î «õí¢´ñ£ù£ô¢ ºîô¤ô¢ javax.swing.table.* âù¢ø Package -¬ù import ªêò¢ò «õí¢´ñ¢. Þ颰 Table âù¢ªø£¼ class â¿î¤ò¤¼è¢è¤ù¢«ø£ñ¢. main function-ô¢ ޼ å¼ ¹î¤ò Object-¬ù à¼õ£è¢°è¤ù¢«ø£ñ¢.Üð¢ªð£¿¶ ïñ袰 Constructor function Þò颰è¤ù¢ø¶. Üî¤ô¢ ï£ñ¢ ºîô¤ô¢ JFrame frame = new JFrame(‘Table’); âù¢Á ªè£´î¢¶ å¼ frame-¬ù à¼õ£è¢è¤è¢ ªè£÷¢è¤«ø£ñ¢. ð¤ù¢ final String [ ] names... âù¢Á ªè£´î¢¶ å¼ String array ò¤¬ù à¼õ£è¢è¤ Üî¤ô¢ ïñ¶ Table -ô¢ õó ޼袰ñ¢ Title-è÷¤ù¢ ªðòó¢è¬÷ð¢ ðî¤è¢è¤ù¢«ø£ñ¢. ܴ final object [ ][ ] data ....... âù¢Á ªè£´î¢¶ å¼ array ò¤¬ù à¼õ£è¢è¤ Üî¤ô¢ ïñ¶ Table ø¢° «î¬õò£ù îèõô¢è÷¢ ܬùî»ñ¢ õó¤¬êò£è ðî¤ï¢¶ ¬õî¢î¤¼è¢ è¤ù¢«ø£ñ¢. Þï¢î Object data type ¬ùð¢ ðòù¢ð´î¢î¤«ò Table Java-15
- 114. 114 ø¢°î¢ «î¬õò£ù ܬù îèõô¢è¬÷»ñ¢ ðî¤ï¢¶ ¬õî¢¶è¢ ªè£÷¢÷«õí¢´ñ¢. ܴ TabelModel datamodel=new AbstractTableModel( ) { ...... } âù¢Á å¼ èì¢ì¬÷î¢ ªî£°ð¢¹ ªè£´è¢èð¢ ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þï¢î TableModel ñø¢Áñ¢ ÞîÂ÷¢ ޼袰ñ¢ ܬù function è¬÷»ñ¢ ¬õî Table-ù¢ ܬù Þòè¢èé¢è¬÷»ñ¢ è좴ð¢ð´î¢¶è¤ù¢«ø£ñ¢. JTable tableview = new JTable (datamodel); âù¢Á ªè£´î¢¶ ï£ñ¢ tableview âù¢Âñ¢ Object-¬ù à¼õ£è¢è¤ò¤¼è¢è¤ù¢«ø£ñ¢. Þï¢î table Ýù¶ datamodel âÂñ¢ Object ô¢ à÷¢÷ îèõô¢ è¬÷ð¢ ðòù¢ð´î¢î¤ ªè£÷¢è¤ù¢ø¶. ܴ JScrollPane scrollpane = new JScrollPane(tableview); âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þï¢î scrollpane Component Ýù¶ âï¢î å¼ Object-®¬ù»ñ¢ frame-ù¢ à÷¢ scroll ªêò¢»ñ¢ ð® ªêò¢õîø¢°ð¢ ðòù¢ð´è¤ù¢ø¶. Þ颰 ï£ñ¢ à¼õ£è¢èò¤¼è¢è¤ù¢ø table-¬ù scrollpane-ù¢ à÷¢ «ð£ì¢®¼è¢è¤ù¢«ø£ñ¢. Þ¼î¤ò£è Þï¢î Scroll Pane -¬ù ï£ñ¢ ïñ¢º¬ìò frame- Â÷¢ add ªêò¢¶ õ¤´è¤ù¢«ø£ñ¢. Þ¶ Þò颰ñ¢ ªð£¿¶ 700, 300 âù¢ø ï¦÷, Üèôî¢î¤ô¢ Þò颰ñ£Á Dimension ܬñè¢èð¢ð좴÷¢÷¶. Classes Provided in the Swing Componenet Package Component Description Japplet Implements a Java applet. JAppletBeanInfo Provides information about JApplett to bean-based tools. JButton Implements a button component. JButtonBeanInfo Provides information about JButton for bean-based tools. JCheckBox Implements a check-box component. JCheckBoxBeanInfo Provides information about JCheckBox for bean-based tools. JCheckBoxMenuItem Implements a check-box menu item.
- 115. 115 JCheckBoxMenuItemBeanInfo Provides information about JCheckBoxMenuItem for bean-based tools. JColorChooser Displays and manages a color-chosser dialog. JColorChooserBeanInfo Provides information about JColorChooser for bean-based tools. JComboBox Implements a combo-box component. JComboBoxBeanInfo Provides information about JComboBox for bean-based tools. JComponent The mother of all Swing components. JComponentBeanInfo Provides information about JComponent for bean-based tools. JDesktopIcon Displays in iconified version of a JInternalFrame. JDesktopIconBeanInfo Provides information about JDesktopIcon for bean-based tools. JDesktopPane Provides a pluggable DesktopManager object for JInternal Frame Objects. JDesktopPaneBean Provides information about JDesktopPane for bean-based Info tools. JDialog Adds enhancements to java.awt.Dialog. JDialogBeanInfo Provides information about JDialog for bean-based tools. JFileChooser Implements a file-chooser dialog box. JFileChooserBeanInfo Provides information about JFileChooser for bean-based tools. JFrame Adds enhancements to java.awt.Frame. JFrameBeanInfo Provides information about JFrame for bean-based tools. JInternalFrame Implements a frame object that can be placed inside a JDestopPane object to emulate a native frame window. JInternalFrameBeanInfo Provides information about JInternalFrame for bean-based tools. JLabel Creates a display area for displaying
- 116. 116 read-only text, an image, or both. JLabelBeanInfo Provides information about JLabel for bean-based tools. JLayeredPane Can display multiple layered panes (JInternalFrameobjects) inside a frame. JLayeredPaneBeanInfo Provides information about JLayeredPane for bean-based tools. JList Allows the user to selcect one or more objects from a list. A separate mode, ListModel, represents the contents of the list. JListBeanInfo Provides information about JList for bean-based tools. JMenu Implements a menu component. JMenuBeanInfo Provides information about JMenu for bean-based tools. JMenuBar Implements a menu bar component. JMenuBarBeanInfo Provides information about JMenuBar for bean-based tools. JMenuItem Implements a menu item component. JMenuItemBeanInfo Provides information about JMenuItem for bean-based tools. JOptionPane Displays a dialog box that prompts the user for a choice ane then passes that choice on to the executing program. JOptionPaneBeanInfo Provides information about JOptionPane for bean-based tools. JPanel Provides a generic container for organizing other components. JPanelBeanInfo Provides information about JPanel for bean-based tools. JPasswordField Displays a field in which the user can type a passord. The text of the pass word does not appear in the field as it is being typed. JPasswordFieldBeanInfo Provides information about JPasswordField for bean-based tools. JPopupMenu Implements a pop-up menu.
- 117. 117 JPopupMenuBeanInfo Provides information about JPopupMenu for bean-based tools. JProgressBar Implements a progress-bar compo- nent. JProgressBarBeanInfo Provides information about JProgressBar for bean-based tools. JRadioButton Implements a radio-button control. JRadioButtonBeanInfo Provides information about JRadioButton for bean-based tools. JRadioButtonMenuItem Implements a radio-button menu item. JradioButtonMenuItemBeanInfo Provides information about JRadioButtonMenuItem for bean- based tools. JRootPane Instantiates in a single step an object made up of a glass pane, a layered pane, an optional menu bar, and
- 118. 118 a content pane. JRootPaneBeanInfo Provides information about JRootPane for bean-based tools. JScrollBar Implements a scroll-bar object. JScrollBarBeanInfo Provides information about JScrollBar for bean-based tools. JScrollPane Implements a scroll-pane object. JScrollPaneBeanInfo Provides information about JScrollPane for bean-based tools. JSeparator Implements a menu separator object. JSeparatorBeanInfo Provides information about JSeparator for bean-based tools. JSlider Implements a slider-bar object. JSliderBeanInfo Provides information about JSlider for bean-based tools. JSplitPane Implements a split-pane component. JSplitPaneBeanInfo Provides information about JSplitPane for bean-based tools. JTabbedPane Implements a tabbed-pane (“prop erty-page”) component. JTabbedPaneBeanInfo Provides information about JTabbedPane for bean-based tools. JTable Implements a table component. JTableBeanInfo Provides information about JTable for bean-based tools. JTextArea Implements a multiline ara that can display editable or read-only text. JTextAreaBeanInfo Provides information about JTextArea for bean-based tools. JTextPane Implements a text component that can be marked up with attributes to be represented graphically. JTextPaneBean-Info Provides information about JTextPane for bean-based tools. JToggleButton Implements a two-stage button com ponent. JToggleButtonBeanInfo Provides information about JToggleButton for bean-based tools.
- 119. 119 JToolBar Implements a dockable, floatable tool bar. JToolBarBeanInfo Provides information about JToolBar for bean-based tools. JToolTip Implements a tool-tip component (a component that can display a short string, such as the name of compo nents or a user tip). JToolTipBeanInfo Provides information about JToolTip for bean-based tools. JTree A component that can display a set of hierarchical data in a graphical outline format. JTreeBeanInfo Provides information about JTree for bean-based tools. JViewport Provides a clipped view of an arbi trarily large component. Used by JScrollPane. JViewportBeanInfo Provides information about JViewport for bean-based tools. JWindow Adds enhancements to java.awt.Window. JWindowBeanInfo Provides information about JWindow for bean-based tools.
- 120. 120 Üî¢î¤ò£òñ¢Üî¢î¤ò£òñ¢Üî¢î¤ò£òñ¢Üî¢î¤ò£òñ¢Üî¢î¤ò£òñ¢ 6. Java Database Connectivity (JDBC) Database âù¢ø£ô¢ âù¢ù âù¢Á àé¢èÀ袰 ïù¢ø£è ªîó¤ï¢î¤¼è¢°ñ¢. îèõô¢è¬÷ å¼ º¬øò£ù õ®õî¢î¤ô¢ (Structure) ðî¤ï¢¶ ¬õî¢¶è¢ ªè£÷¢õ¶ Database Ý°ñ¢. Oracle, Ms-Sql Server, Ms-Access, Sybale âù¢Á ðô Database ªñù¢ªð£¼ì¢è÷¢ ¹öè¢èî¢î¤ô¢ à÷¢÷ù. Þõø¢ø¤ô¢ ï£ñ¢ ñ¤èî¢î¤ø¬ñò£è îèõô¢è¬÷ ¬èò£÷ º®»ñ¢. ªð£¶õ£è Þî¢î¬èò database-è¬÷ Back end Tool âù¢Á ܬöð¢ð£ó¢è÷¢. Þõø¢ø¤ô¢ îèõô¢è¬÷ð¢ ðî¤ï¢¶ñ¢ ñø¢Áñ¢ Üõø¢ø¤ô¢ ޼ ªðø¢Áè¢ ªè£÷¢Àñ£Áñ¢ ðòù¢ð´î¢¶ñ¢ ªñù¢ªð£¼ì¢è¬÷ front ent tool âù¢Á ܬöð¢ð£ó¢è÷¢. ªð£¶õ£è windows operating system -î¢î¤ô¢ Open Database Connectivity (ODBC) âù¢ø º¬ø åù¢Á à÷¢÷¶. Þï¢î º¬øò¤¬ùð¢ ðòù¢ð´î¢î¤ Visual Basic, Power Builder , Java âù¢Á âï¢î ªñù¢ªð£¼÷¤ô¢ ï¦é¢è÷¢ «õ¬ô ªêò¢î£½ñ¢ Üî¤ô¤¼ï¢¶ Oracle, Access ºîô¤ò Database-èÀìù¢ ªî£ìó¢¹ ªè£÷¢÷ º®»ñ¢. Þï¢î ODBC º¬øò¤¬ù java-¾ìù¢ Þ¬íð¢ðîø¢è¢ªèù¢Á Þ¼è¢è¤ù¢ø èì¢ì¬÷î¢ ªî£°ð¢¹è¬÷î¢î£ù¢ Java Database Connectivity âù¢Á ܬöè¢è¤ù¢«ø£ñ¢. Data Source Name ï£ñ¢ âï¢î Database-¬ù ðòù¢ð´î¢î õ¤¼ñ¢¹è¤ù¢«ø£«ñ£ Üî¬ùð¢ðø¢ø¤ò îèõô¢è¬÷ ºîô¤ô¢ Data Source âù¢Âñ¢ õ®õî¢î¤ô¢ «êèó¤è¢è «õí¢´ñ¢. Þîø¢° Windows-ô¢ à÷¢÷ Control Panel ø¢° ºîô¤ô¢ ªêô¢ô «õí¢´ñ¢. Ü颰 ODBC Data Source âù¢Âñ¢ tool Ýù¶ Þîø¢°ð¢ ðòù¢ð´è¤ù¢ø¶. â´î¢¶è¢è£ì¢ì£è Þð¢ªð£¿¶ ï£ñ¢ Microsoft Access Database-ô¢ à÷¢÷ å¼ MDB file-ô¢ ޼袰ñ¢ Table -ô¤¬ù Java ¹«ó£è¤ó£ñ¢ õö¤ò£è JDBC º¬øò¤¬ùð¢ ðòù¢ð´î¢î¤ ¬èò£÷¢õ¬îè¢ è£íô£ñ¢. 覫ö à÷¢÷ ðìé¢è÷¤ô¢ ªè£´è¢èð¢ð좴÷¢÷õ£Á Window-ô¢ à÷¢÷ Control Panel-ô¢ ޼袰ñ¢ ODBC Data Source âù¢Âñ¢ tool-¬ù Þòè¢è¤ Ü颰 ïñ袰 âï¢î Database-ô¢ à÷¢÷ îèõô¢è¬÷ ¬èò£÷ «õí¢´«ñ£ Üîø¢è¢°ø¤ò Device- ¬ù ªîó¤¾ ªêò¢¶ ð¤ù¢ùó¢ Üî¤ô¢ ïñ袰 âï¢î Table «õí¢´«ñ£ Üî¬ù»ñ¢ ªîó¤¾ ªêò¢¶ å¼ DSN ªðòó¤¬ù»ñ¢ ªè£´î¢¶è¢ ªè£÷¢Àé¢è÷¢. Þ颰 ï£ñ¢ Student.mdb âù¢Âñ¢ Access file ø¢° Arshad âù¢Âñ¢ ªðòó¤¬ù ªè£´î¢¶ å¼
- 121. 121 DSN-ù¤¬ù à¼õ£è¢è¤ò¤¼è¢è¤ù¢«ø£ñ¢. Þï¢î Student âù¢Âñ¢ mdb file-ô¢ 覫ö ªè£´è¢èð¢ð좴÷¢÷¶ «ð£ô¢ sno, sname, tamil, english, maths âù¢Á field è¬÷»¬ìò table åù¢¬ø à¼õ£è¢è¤ ªè£÷¢Àé¢è÷¢. ðì‹ðì‹ðì‹ðì‹ðì‹ 6.1 ðì‹ðì‹ðì‹ðì‹ðì‹ 6.2
- 124. 124 Listing 6.1 import java.sql.*; class jdbcdemo { public static void main(String ag[]) { int sno; String sname; int tam,eng,maths,tot; String url=”jdbc:odbc:arshad”; try { Class.forName(“sun.jdbc.odbc.JdbcOdbcDriver”); // initialise Connection cn=DriverManager.getConnection(url,””,””); // establishing a connection String sql=”select sno,sname,tamil,english,maths from student”; // forming a query System.out.println(cn.nativeSQL(sql)); Statement s1=cn.createStatement(); // creating a statement object, whill will maintain transactions ResultSet rs=s1.executeQuery(sql); // executing a query and holds the data while(rs.next()) // skips next record { sno=rs.getInt(1); // retriving the fields... sname=rs.getString(2); tam=rs.getInt(3); eng=rs.getInt(4); maths=rs.getInt(5); tot=tam+eng+maths; System.out.println(sno+” “+sname+” “+tam+”
- 125. 125 “+eng+” “+maths+” “+tot); } cn.close(); }catch(Exception e) { System.out.println(“incorrect query”); } } } Þï¢î ¹«ó£è¤ó£ñ¢ Student âù¢Âñ¢ Access table-ô¢ à÷¢÷ ܬù Record ´è¬÷»ñ¢ display ªêò¢»ñ£Á â¿îð¢ð좮¼è¢è¤ù¢ø¶. ï£ñ¢ JDBC ò¤¬ù ðòù¢ð´î¢î «õí¢´ñ¢ âù¢ø£ô¢ ºîô¤ô¢ import java.sql.*; âù¢Âñ¢ Package-¬ù import ªêò¢¶ ªè£÷¢÷ «õí¢´ñ¢. main ( ) function -ô¢ sno, sname, tam, eng, mat, tot Ýè¤ò variable-è÷¢ à¼õ£è¢èð¢ð좮¼è¢è¤ù¢øù. Þõø¢ø¤ô¢ î£ù¢ database Record-è÷¤ô¢ Þ¼è¢è¤ù¢ø ñî¤ð¢¹è¬÷ â´î¢¶ «ð£ì Þ¼è¢è¤ù¢«ø£ñ¢. ºîô¤ô¢ Þï¢î ¹«ó£è¤ó£ñ¢ º¿õ¶ñ¢ try { } catch âù¢Âñ¢ exception- è¬÷ èí¢´ ð¤®è¢°ñ¢ Loop Â÷¢ â¿îð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. ªð£¶õ£è try { } Catch -ù¢ à÷¢ ¹«ó£è¤ó£ñ¢ ⿶ñ¢ªð£¿¶ ¹«ó£è¤ó£ñ¤ù¢ Þòè¢èî¢î¤ô¢ ãî£õ¶ error-è÷¢ ޼袰ñ¢ ðì¢êî¢î¤ô¢ exception âù¢ù âù¢ðî¬ùè¢ ªè£í¢´ îõÁè¬÷ î¢î¤è¢ ªè£÷¢÷ Þò½ñ¢. Þï¢î ¹«ó£è¤ó£ñ¤¬ù ªð£¼î¢îõ¬óò¤ô¢ ܶ Þò颰ñ¢ªð£¿¶ âù¢ù îõÁ ïìï¢î£½ñ¢ Incorrect query âù¢Á õ¼ñ¢ð® â¿îð¢ð좮¼è¢è¤ù¢ø¶. Class.for.name(‘Sun.jdbc.odbc.jdbc.ODBC Driver’); âù¢Á ï£ñ¢ ºîô¤ô¢ ܬù JDBC ¹«ó£è¤ó£ñ¤é¢°è÷¤½ñ¢ ªè£´è¢è «õí¢´ñ¢. ܴ âï¢î Database àìù¢ Þ¬íè¢è «õí¢´ñ¢ âù¢Á ªê£ô¢õ îø¢è¢è£è Connection âÂñ¢ class-ù¢ Object åù¢¬ø DSN ªðòó¤ù¢ ¶¬íè¢ ªè£í¢´ à¼õ£è¢è «õí¢´ñ¢. âù«õ î£ù¢ Connection n=DriverManager.getConnection(url,‘’,’’); âù¢Á à¼õ£è¢èð¢ð좴÷¢÷¶. ܴ ï£ñ¢ record -è¬÷ Table -ô¢ ޼ â´ð¢ðîø¢è¢è£è å¼ SQL query-ò¤¬ù â¿î «õí¢´ñ.¢Üî¬ù ï£ñ¢ å¼
- 126. 126 variable-ô¢ ðî¤ï¢¶ ¬õî¢¶è¢ ªè£÷¢÷ô£ñ¢. âù«õ î£ù¢ String sql=”select sno, sname, tamil, english, maths from Student”; âù¢Á ªè£´î¢î¤¼è¢è¤ù¢«ø£ñ¢. Þï¢î query ò¤¬ù Þò袰õîø¢è¢è£è ºîô¤ô¢ ï£ñ¢ Statement âù¢Âñ¢ Class -ù¢ Object-ä à¼õ£è¢è «õí¢´ñ¢. âù«õ î£ù¢ Statement sl = cn.createStatement( ); âù¢Á à¼õ£è¢è¤ò¤Áè¢è¤ù¢«ø£ñ¢. Þîù¢ ªð£¼÷¢ cn âù¢Âñ¢ Connection Class Object -®ô¢ ï£ñ¢ ªè£´è¢èð¢«ð£°ñ¢ èì¢ì¬÷, Þò颰ñ¢ «õí¢´ñ¢ âù¢ø ªð£¼÷¢ Ý°ñ¢. ܴ ResultSet rs = sl.executeQuery(Sql); âù¢Á ªè£´î¢î¤¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þï¢î executeQuery èì¢ì¬÷î£ù¢ ïñ¢º¬ìò query ò¤¬ù Þòè¢è¤ database-ô¢ à÷¢÷ record-è¬÷ â´î¢¶ Resultset âù¢Âñ¢ class -ù¢ Object Ýù¶ rs -ô¢ «ð£´è¤ù¢ø¶. Þð¢ªð£¿¶ rs âù¢Âñ¢ Object-®ô¢ Student table-ô¢ à÷¢÷ ܬù record-èÀñ¢ Þ¼è¢è¤ù¢øù. Record Pointer Ýù¶ ºîô¢ Record -®ô¢ Þ¼è¢è¤ù¢ø¶. åõ¢ªõ£¼ record Ýè end of file õ¼ñ÷¾ñ¢ display ªêò¢õîø¢° while(rs.next( )) âù¢Âñ¢ Loop Þòè¢èð¢ð좮¼è¢è¤ù¢ø¶. Þîù¢ à÷¢ åõ¢ªõ£¼ record Ýè Move Ý°ñ¢ ªð£¿¶ Üï¢îï¢î record -è÷¤ô¢ à÷¢÷ field -è÷¤ô¢ integer data type à÷¢÷õø¢ø¤ô¢ Þ¼è¢è¤ù¢ø ñî¤ð¢¹è¬÷𢠪ð¼õîø¢° getInt( ) âÂñ¢ function Âñ¢ String data type-ô¢ à÷¢÷ ñî¤ð¢¹è¬÷ ªð¼õîø¢° getString( ) âù¢ùñ¢ function -Âñ¢ ðòù¢ð´î¢îð¢ ð좮¼è¢è¤ù¢ø¶. Þõø¢ø¤ô¢ ªè£´è¢èð¢ð좴÷¢÷ 1,2,3, âù¢Âñ¢ âí¢è÷¢ table -è÷¤ô¢ à÷¢÷ field è÷¤ù¢ õó¤¬êò¤¬ùè¢ °ø¤è¢è¤ù¢øù.
- 127. 127 ðì‹ðì‹ðì‹ðì‹ðì‹ 6.7 Listing 6.2 import java.sql.*; class jdbcstore { public static void main(String argv[]) { String url=”jdbc:odbc:arshad”; try { Class.forName(“sun.jdbc.odbc.JdbcOdbcDriver”); Connection connection= DriverManager.getConnection(url,””,””); String sql=”insert into student values (106,’Hameetha’,87,72,64)”; // String sql=”delete from student”; // String sql=”update student set sname=’Simran’ where sno=106"
- 128. 128 System.out.println(“native form: “ + connection.nativeSQL(sql)); Statement statement= connection.createStatement(); statement.executeUpdate(sql); }catch (Exception ex) { System.out.println(“A problem occured: “ + ex); } } } database-ô¢ ¹î¤ò record-è¬÷ð¢ ðî¤õîø¢è¢°ñ¢, Þ¼è¢è¤ù¢ø record-è¬÷ Delete ªêò¢õîø¢è¢°ñ¢, ãø¢ªèù«õ Þ¼è¢è¤ù¢ø record-è¬÷ update ªêò¢õîø¢°ñ¢ å«ó å¼ ¹«ó£è¤ó£ñ¤é¢ º¬øî£ù¢ ðòù¢ð´è¤ù¢ø¶. ܶ î£ù¢ Þï¢î ¹«ó£è¤ó£ñ¤ô¢ ðòù¢ð´î¢î¢ð¢ð좮¼è¢è¤ù¢ø¶. àé¢èÀ袰 Structured Query Language (SQL) âù¢ø¬öè¢èð¢ð´ñ¢ ªñ£ö¤ ªîó¤ï¢î¤¼ï¢î£ô¢ ñ좴«ñ JDBC ¹«ó£è¤ó£ñ¢è¬÷ ðòù¢ð´î¢¶õ¶ â÷¤î£è ޼袰ñ¢ âù¢ðî¬ù 郎ùõ¤ô¢ ªè£÷¢Àé¢è÷¢. ãªùù¤ô¢ select, insert, update, delete ºîô£ù èì¢ì¬÷è÷¢ Oracle, Access âù¢Á ܬù database è÷¤½ñ¢ å«ó ñ£î¤ó¤ò£è«õ Þò颰è¤ù¢øù. Üõø¢¬øî¢î£ù¢ ï£ñ¢ Þ颰ñ¢ ðòù¢ð´î¢î¤ ò¤¼è¢è¤ù¢«ø£ñ¢. Þï¢î ¹«ó£è¤ó£ñ¤ô¢ ï£ñ¢ executeQuery âù¢Á ªè£´ð¢ðîø¢°ð¢ ðî¤ô£è executeUpdate(sql) âù¢Á ªè£´î¢î¤¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þï¢î å¼ èì¢ì¬÷ò¤¬ùð¢ ðòù¢ð´î¢î¤ insert, update, delete Ýè¤ò «õ¬ôè¬÷ê¢ ªêò¢¶ ªè£÷¢÷ô£ñ¢. Þ颰 Íù¢Á èì¢ì¬÷èÀñ¢ â´î¢¶è¢è£ì¢´è¢è£è ªè£´è¢èð¢ð좴 Üõø¢ø¤ô¢ Þóí¢´ // âù¢Á ªè£´î¢¶ Comment ªêò¢òð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢.
- 129. 129 ðì‹ðì‹ðì‹ðì‹ðì‹ 6.8 ¹«ó£è¤ó£ñ¢ Þòé¢è¤ º®î¢î ð¤ù¢ table-ô¢ î°ï¢î ñ£ø¢øé¢è÷¢ ï¬ì𢠪ðø¢ø¤¼è¢è¤ù¢øùõ£ âù¢ðî¬ùê¢ «ê£î¤î¢¶ð¢ ð£ó¢î¢¶è¢ ªè£÷¢Àé¢è÷¢.
- 130. 130 Üî¢î¤ò£òñ¢ 7Üî¢î¤ò£òñ¢ 7Üî¢î¤ò£òñ¢ 7Üî¢î¤ò£òñ¢ 7Üî¢î¤ò£òñ¢ 7 Thread Multi tasking âù¢ø õ£ó¢î¢¬îò¤¬ùð¢ðø¢ø¤è¢ «è÷¢õ¤ð¢ð좮¼ð¢ð¦ó¢è÷¢. Üî£õ¶ å«ó «ïóî¢î¤ô¢ ðô «õ¬ôè¬÷ê¢ ªêò¢»ñ¢ º¬ø. ªð£¶õ£è windows operating system Ýù¶ Multitasking º¬øò¤ô¢î£ù¢ «õ¬ôê¢ ªêò¢è¤ù¢ø¶. Þî¤ô¢ ï£ñ¢ å«ó «ïóî¢î¤ô¢ ðô¢«õÁ ªñù¢ªð£¼÷¢è¬÷ Þòè¢è¤è¢ ªè£÷¢÷ô£ñ¢. Micro Processor -ø¤¬ù å«ó «ïóî¢î¤ô¢ ðô «õ¬ôè¬÷ê¢ ªêò¢»ñ¢ñ£Á ¹«ó£è¤ó£ñ¢è÷¢ ⿶õîø¢° Java-õ¤ô¢ Thread âù¢Âñ¢ Class -ù¢ ªî£°ð¢¹ ðòù¢ð´è¤ù¢ø¶. ï¦é¢è÷¢ Visual Basic -ô¢ Timer âù¢ªø£¼ Tool -ô¤¬ùð¢ ðòù¢ð´î¢î¤ò¤¼è¢è¤ù¢ø¦ó¢è÷£? ãªùù¤ô¢ Thread-ñ¢ Üîù¢ Þòè¢èî𢠫ð£ô«õ î£ù¢ Þò颰è¤ù¢ø¶. Üî£õ¶ Thread Ýù¶ å¼ è®è£óñ¢ Ý°ñ¢. 覫ö ªè£´è¢èð¢ð좴÷¢÷ ¹«ó£è¤ó£ñ¤ô¢ Thread class ¬ù ðòù¢ð´î¢î¤ å¼ Clock ¹«ó£è¤ó£ñ¢ â¿îð¢ð좴÷¢÷¶. Þï¢î𢠹«ó£è¤ó£ñ¤ù¢ Þòè¢èî¢î¤¬ù ªî÷¤õ£è ¹ó¤ï¢¶ ªè£÷¢õ¦ó¢è«÷ò£ù£ô¢ Thread-ù¢ Þòè¢èñ¢ àé¢èÀ袰 ªî÷¤õ£è ¹ó¤»ñ¢. Listing 7.1 import java.awt.*; import java.applet.Applet; import java.util.*; public class clock extends Applet implements Runnable { Thread runner; public void init() { } public void start() { if (runner==null) {
- 131. 131 runner=new Thread(this); runner.start(); } } public void stop() { if (runner!=null) { runner=null; } } public void run() { Thread thisthread=Thread.currentThread(); while (runner==thisthread) { repaint(); try { Thread.sleep(1000); } catch(InterruptedException e) { } } } public void paint(Graphics screen) { Date hello=new Date(); screen.setFont(new Font(“Serif”, Font.BOLD+Font.ITALIC,24)); screen.drawString(hello.toString(),50,50); }
- 132. 132 } Þ¶ å¼ applet ¹«ó£è¤ó£ñ£è â¿îð¢ð좴÷¢÷¶. Þï¢î applet Þò颰ñ¢ ªð£¿¶ ïñ袰 å¼ Clock å®è¢ªè£í¢®¼ð¢ð¶ ªîó¤»ñ¢. Thread âù¢Âñ¢ Class Ýù¶ java.util.* âù¢Âñ¢ Package -ô¢ Þ¼è¢è¤ù¢ø¶. âù«õ î£ù¢ Üï¢î Package- ¬ù ï£ñ¢ import ªêò¢î¤¼è¢è¤ù¢«ø£ñ¢. ð¤ù¢ public class clock extends Applet implements Runnable âù¢Á class õ¬óò¤¼è¢èð¢ ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þ颰 Runnable âù¢Âñ¢ Interface Ýù¶ ðòù¢ð´î¢îð¢ð좮¼è¢è¤ù¢ø¶. Þï¢î Runnable Interface ¬ù implement ªêò¢õîù¢ Íô«ñ ïñ袰 Thread -¬ù ïñ¶ ¹«ó£è¤ó£ñ¤ô¢ ðòù¢ð´î¢î¤è¢ ªè£÷¢÷ º®»ñ¢. «ñ½ñ¢ start ( ), stop ( ), run ( ) Ýè¤ò event è¬÷»ñ¢ ðòù¢ð´î¢î¤è¢ ªè£÷¢÷ º®»ñ¢. Þï¢î ¹«ó£è¤ó£ñ¢ ªè£´è¢èð¢ð좴÷¢÷ start ( ) event Ýù¶ init ( ) function Þòé¢è¤ò ð¤ù¢ î£ù£è Þòé¢è¤õ¤´ñ¢. ð¤ù¢ùó¢ run( ) event î£ù£è Þò颰ñ¢. ¹«ó£è¤ó£ñ¢ º®»ñ¢ õ¬ó run ( ) event -®ù¢ à÷¢«÷«ò Control ï£ñ¢ ޼袰ñ£Á ð£ó¢î¢¶è¢ ªè£÷¢÷ «õí¢´ñ¢. âð¢ªð£¿¶ ¹«ó£è¤ó£ñ¢ º®è¤ù¢ø«î£ Üð¢ªð£¿¶ stop( ) event î£ù£è Þò颰ñ¢. ðì‹ðì‹ðì‹ðì‹ðì‹ 7.1
- 133. 133 ¹«ó£è¤ó£ñ¢ Ýóñ¢ðî¢î¤ô¢ Thread runner âù¢Á ªè£´î¢¶ å¼ Thread object define ªêò¢òð¢ð좮¼è¢è¤ù¢ø¶. start event-®ô¢ runner=new Thread(this); runner.start( ); âù¢Á ªè£´î¢î¤¼ð¢ðîù¢ Íôñ¢ Thread à¼õ£è¢èð¢ð좴, ܶ Þòé¢è¾ñ¢ Ýóñ¢ð¤è¢è¤ù¢ø¶. runner âù¢Âñ¢ Object Ýù¶ å¼ è®è£óñ¢ «ð£ô¢ Þò颰è¤ù¢ø¶. ܴ ¹«ó£è¤ó£ñ¤ù¢ è좴ð¢ð£´ º¿õ¶ñ¢ run event -®Â÷¢ õ õ¤´è¤ù¢ø¶. ÞîÂ÷¢ å¼ loop ܬñè¢èð¢ð좮¼è¢è¤ù¢ø¶. ºîô¤ô¢ Thread thisthread=Thread.currentThread( ); âù¢Á ªè£´î¢î¤¼ð¢ðîù¢ Íôñ¢ thisthread âù¢Á ¹î¤ò Thread object -®¬ù à¼õ£è¢è¤ ÜîÂ÷¢ îø¢ªð£¿¶ Þòé¢è¤é¢è¤è¢ ªè£í¢®¼è¢°ñ¢ current Thread Ýù runner-ô¢ âù¢ù ñî¤ð¢¹ Þ¼è¢è¤ù¢ø«î£ Üî¬ù ðî¤ï¢¶ ¬õè¢è¤ù¢«ø£ñ¢. ð¤ù¢ùó¢ while (runner==thisthread) âù¢ø condition ªè£´î¢¶ loop åù¢ø¤Â÷¢ ªêô¢½è¤ù¢«ø£ñ¢. Üî£õ¶ runner ñø¢Áñ¢ thisthread Ýè¤ò Þóí¢´ Object-è÷¤½ñ¢ å«ó ñî¤ð¢¹ ޼袰ñ¢ ðì¢êî¢î¤ô¢ loop-ù¢ à÷¢ ªêô¢ô «õí¢´ñ¢ âù¢ø ªð£¼÷£°ñ¢. loop -ù¢ à÷¢ Þóí¢´ èì¢ì¬÷è÷¢ ªè£´è¢èð¢ð좴÷¢÷ù. Üî¤ô¢ Thread.sleep(1000); âù¢Á ªè£´è¢èð¢ðì¢ì®¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þ颰 1000 âù¢ð¶ MilliSecond- ®¬ùè¢ °ø¤è¢è¤ù¢ø¶. Üî£õ¶ sleep function Ýù¶ Þ颰 Micro Processor- ¬ù 1000 MilliSecond -è÷¢ Üî£õ¶ å¼ Second Ü÷õ¤ø¢° âï¢î «õ¬ô¬ò»ñ¢ ªêò¢ò£ñô¢ 祿î¢î¤ ¬õè¢è¤ù¢ø¶. Üî£õ¶ ¶£é¢è ¬õè¢è¤ù¢ø¶. repaint() function call ªêò¢òð¢ð좮¼ð¢ðî£ô¢ paint ( ) function Þò颰è¤ù¢ø¶. ÜîÂ÷¢ ï£ñ¢ Date hello=new Date( ); screen.setFont(new Font(‘Serif’, Font.Bold +Font.Italic, 24)); screen.drawString(hello.toString( ), 50, 50); âù¢Á ªè£´î¢î¤¼è¢è¤ù¢«ø£ñ¢. Üî£õ¶ åõ¢ªõ£ù¢Á º¬ø paint ( ) function Þò颰ñ¢ ªð£¿¶ñ¢ Date class -ø¢è¢° object à¼õ£è¢èð¢ð´õî£ô¢ îø¢ªð£¿¶
- 134. 134 èí¤ð¢ªð£ø¤ò¤ô¢ à÷¢÷ Clock-ô¢ âï¢î «ïóñ¢ Þ¼è¢è¤ù¢ø«î£ Üîù¢ ñî¤ð¢¹ hello object-®ù¢ à÷¢ ðî¤ï¢¶ õ¤´è¤ù¢ø¶. Üî¬ù ï£ñ¢ hello.toString( ) function õö¤ò£è Screen-ô¢ display ªêò¢¶ ªè£÷¢è¤ù¢«ø£ñ¢. ªñ£î¢îî¢î¤ô¢ ¹«ó£è¤ó£ñ£ù¶ åõ¢ªõ£Á second èö¤î¢¶ paint( ) function- ä Þò袰ñ¢ ªð£¿¶ ïñ袰 øò¤ô¢ Clock å®è¢ªè£í¢®¼ð¢ð¶ ªîó¤è¤ù¢ø¶. ÞÁî¤ò¤ô¢ ï¦é¢è÷¢ âð¢ªð£¿¶ applet -®¬ù class ªêò¢è¤ù¢ø¦ó¢è«÷£ Üð¢ªð£¿¶ stop event î£ù£è Þò袰è¤ù¢ø¶. ÜîÂ÷¢ runner=new âù¢Á ªè£´î¢î¤¼ð¢ðîù¢ Íôñ¢ Thread-®ù¢ Þòè¢èñ¢ ï¤ù¢Á õ¤´è¤ù¢ø¶. Listing7.2 import java.awt.*; import java.applet.Applet; import java.util.*; public class anim extends Applet implements Runnable { Image theimage[]=new Image[10]; String dir=”Images/”; String name=”T”; String ext=”.gif”; Thread runner; int cnt=0; public void init() { int i; for (i=0;i<10;i++) { theimage[i]=getImage(getDocumentBase(), dir+name+(i+1)+ext); } }
- 135. 135 public void start() { if (runner==null) { runner=new Thread(this); runner.start(); } } public void stop() { if (runner!=null) { runner=null; } } public void run() { Thread thisthread=Thread.currentThread(); while (runner==thisthread) { repaint(); try { Thread.sleep(200); } catch(InterruptedException e) { } } } public void paint(Graphics screen) { if (cnt==10) {
- 136. 136 cnt=0; } screen.drawImage(theimage[cnt++],0,0,this); } } Þï¢î ¹«ó£è¤ó£ñ£ù¶ å¼ Animation õ¼ñ£Á â¿îð¢ð좮¼è¢è¤ù¢ø¶. ï¦é¢è÷¢ cartoon -è÷¢ ñø¢Áñ¢ ðô Graphics è£ì¢ê¤è¬÷ ªî£¬ôè¢è£ì¢ê¤è÷¤ô¢ ð£ó¢î¢î¤¼ð¢ð¦ó¢è÷¢. Üõø¢¬øªòô¢ô£ñ¢ èí¤ð¢ªð£ø¤ò¤ô¢ î£ù¢ à¼õ£è¢° è¤ù¢ø£ó¢è÷¢ âù¢ð¶ñ¢ àé¢èÀè¢°î¢ ªîó¤»ñ¢. Þ𢹫ó£è¤ó£ñ£ù¶ Animation-è÷¢ âõ¢õ£Á â¿îð¢ð´è¤ù¢øù âù¢ðîø¢° å¼ ê¤Á â´î¢¶è¢è£ì¢´ Ý°ñ¢. ªð£¶õ£è Animation ªêò¢»ñ¢ ªð£¿¶ ðô Image-è÷¢ «î¬õð¢ð´è¤ù¢øù. Üî£õ¶ åõ¢ªõ£Á Animation movement-ø¢è¢°ñ¢ âù¢Á îù¤î¢îù¤ image file-è÷¢ «õí¢´ñ¢. Üï¢î file-è¬÷ å¼ °ø¤ð¢ð¤ì¢ì è£ô Þ¬ìªõ÷¤è¢°÷¢ ê¦ó£è Display Ý°ñ¢ð® ªêò¢õ«î Animation ¹«ó£è¤ó£ñ¢ Ý°ñ¢. Þï¢î ¹«ó£è¤ó£ñ¤¬ù ï¦é¢è÷¢ Þòè¢è «õí¢´ñ¢ âù¤ô¢ ºîô¤ô¢ gif file- è¬÷ à¼õ£è¢è¤è¢ ªè£÷¢Àé¢è÷¢. Üõø¢ø¤ô¢ å¼ Animation à¼õ£õîø¢è¢è£ù ªî£ìó¢ê¢ê¤ò£ù movement-è÷¢ ޼袰ñ¢ð® ð£ó¢î¢¶è¢ ªè£÷¢Àé¢è÷¢. â´î¢¶è¢ è£ì¢ì£è å¼ Bus ªð£ñ¢¬ñò£ù¶ Þìð¢ðè¢è ͬôò¤ô¤¼ï¢¶ õô¶ ðè¢èî¢î¤ø¢° ïèó¢õ¶ «ð£ô ð ðìé¢è¬÷ õ¬ó ªè£÷¢Àé¢è÷¢. ï¦é¢è÷¢ Bmp, Gif, Jpg ºîô¤ò âï¢î õ¬è Graphics File-è¬÷ «õí¢´ñ£ù½ñ¢ à¼õ£è¢è¤è¢ ªè£÷¢Àé¢è÷¢. Þ颰 T1.gif, T2.gif, T3.gif... âù¢Á ªðòó¢ õ¼ñ£Á ð file- è¬÷ õ¬ó Þ¼è¢è¤ù¢«ø£ñ¢. ¹«ó£è¤ó£ñ¤ù¢ Ýóñ¢ðî¢î¤ô¢ Image theImage[ ] = new Image[10]; âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þï¢î Image Class-ù¢ object- è÷¤ô¢ î£ù¢ ïñ¢ñ£ô¢ Graphics file -è÷£ù Bmp, Gif, Jpg ºîô£ùõø¢ø¤ô¢ Þ¼è¢è¤ù¢ø îèõô¢è¬÷ ðî¤ï¢¶ ¬õî¢¶è¢ ªè£÷¢÷ º®»ñ¢. String dir = “Images/”; String name= “T”; String ext = “gif”; âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þ¬õ º¬ø«ò file Ýù¶ âï¢î Directory-ò¤ô¢ Þ¼è¢è¤ù¢ø¶, âï¢î â¿î¢î¤ù¤ô¢ ªðòó£ù¶ Ýóñ¢ð¤è¢è¤ù¢ø¶ ñø¢Áñ¢ âù¢ù extension -ä ªè£í¢®¼è¢è¤ù¢ø¶ «ð£ù¢øõø¢¬øè¢ °ø¤è¢è¤ù¢ø¶.
- 137. 137 ðì‹ðì‹ðì‹ðì‹ðì‹ 7.2 (T1.gif) ðì‹ðì‹ðì‹ðì‹ðì‹ 7.3 (T2.gif) ðì‹ðì‹ðì‹ðì‹ðì‹ 7.4 (T3.gif) ðì‹ðì‹ðì‹ðì‹ðì‹ 7.5 (T4.gif) ðì‹ðì‹ðì‹ðì‹ðì‹ 7.6 (T5.gif)
- 138. 138 ðì‹ðì‹ðì‹ðì‹ðì‹ 7.7 (T6.gif) ðì‹ðì‹ðì‹ðì‹ðì‹ 7.8 (T7.gif) ðì‹ðì‹ðì‹ðì‹ðì‹ 7.9 (T8.gif) ðì‹ðì‹ðì‹ðì‹ðì‹ 7.10 (T9.gif) ðì‹ðì‹ðì‹ðì‹ðì‹ 7.11 (T10.gif)
- 139. 139 init ( ) function-ô¢ for loop åù¢Á 10 º¬ø Þò颰ñ£Á ªêò¢òð¢ð좴 getImage (...) âù¢Âñ¢ function-ù¤ù¢ Íôñ¢ åõ¢ªõ£Á Image file Ýè read ªêò¢òð¢ð좴 theImage array-ò¤Â÷¢ «ð£ìð¢ð´è¤ù¢ø¶. ð¤ù¢ start( ) event-®ô¢ runner Thread à¼õ£è¢èð¢ð좴, Þòè¢èð¢ð´è¤ù¢ø¶. ªêù¢ø ¹«ó£è¤ó£ñ¤ù¤¬ù𢠫ð£ô«õ run ( ) event-ñ¢ loop åù¢ø¤Â÷¢ ñ¢ð ñ¢ð ¹«ó£è¤ó£ñ¢ º®»ñ¢ õ¬ó Þò颰è¤ù¢ø¶. åõ¢ªõ£Á 200 MilliSecond- è÷¢ èö¤î¢¶ñ¢ paint ( ) function Þò颰è¤ù¢ø¶. paint ( ) function-ô¢ ï£ñ¢ drawImage âù¢Âñ¢ function -ù¤¬ùð¢ ðòù¢ð´î¢î¤ theImage array ò¤ô¢ à÷¢÷ ðìé¢è¬÷ åõ¢ªõ£ù¢ø£è display ªêò¢¶ ªè£÷¢è¤ù¢«ø£ñ¢. cnt variable åõ¢ªõ£Á º¬ø Þò颰ñ¢ ªð£¿¶ñ¢ îù¢Â÷¢ å¼ ñî¤ð¢ð¤¬ù Ãì¢®è¢ ªè£÷¢è¤ø¶. Üî¤ô¢ âð¢ªð£¿¶ 10 âù¢ø ñî¤ð¢¹ õ¼è¤ù¢ø«î£ Üð¢ªð£¿¶ 0 âù¢ø ñî¤ð¢ð¤¬ù initialize ªêò¢¶ ªè£÷¢è¤ù¢ø¶. âù«õ ¹«ó£è¤ó£ñ¢ Þò颰ñ¢ ªð£¿¶ 10 Image file è÷¤ô¢ à÷¢÷ ðìé¢èÀñ¢ ñ¢ðî¢î¤¼ñ¢ð display Ýè¤è¢ ªè£í¢«ì Þ¼ð¢ðî£ô¢ Animation ïñ袰 褬ìè¢è¤ù¢ø¶. Þï¢î º¬ø animation-è÷¢ Internet- ®ô¢ ðóõô£èð¢ ðòù¢ð´î¢îð¢ð´è¤ù¢øù.
- 140. 140 Üî¢î¤ò£òñ¢ 8Üî¢î¤ò£òñ¢ 8Üî¢î¤ò£òñ¢ 8Üî¢î¤ò£òñ¢ 8Üî¢î¤ò£òñ¢ 8 Files Java õ¤ô¢ java.io.file âù¢Á å¼ package Þ¼è¢è¤ù¢ø¶. Þî¤ô¢ à÷¢÷ class è¬÷ð¢ ðòù¢ð´î¢î¤ ïñ¢ñ£ô¢ low level file operation-è¬÷ ªêò¢¶ ªè£÷¢÷ Þò½ñ¢. Üî£õ¶ ¹î¤ò file-è¬÷ à¼õ£è¢èõ¶ ãø¢è¢ªèù«õ Þ¼è¢è¤ù¢ø file è¬÷ read ªêò¢¶ ªè£÷¢õ¶ ºîô£ù «õ¬ôè¬÷ê¢ ªêò¢¶ ªè£÷¢÷ô£ñ¢. Listing 8.1 import java.io.File; class FileQuery { public static void main(String args[]) { String dirname=”india”; String filename=”store.java”; File myfile=new File(dirname,filename); System.out.println(“File Name: “ + myfile.getName()); System.out.println(“Is it a Directory : “ + myfile.isDirectory()); System.out.println(“It is a real file : “ + myfile.isFile()); System.out.println(“File Path: “ + myfile.getPath()); System.out.println(“Absolute File Path: “ + myfile.getAbsolutePath()); System.out.println(“Is File Readable: “ + myfile.canRead()); System.out.println(“Is File Writeable: “ + myfile.canWrite()); System.out.println(“Modified on: “ + myfile.lastModified()); System.out.println(“Size (in bytes): “ + myfile.length()); System.out.println();
- 141. 141 System.out.println(“—— Directory Listing ——”); File dir=new File(dirname); if (dir.isDirectory()==false) { System.out.println(dirname + “is not a directory”); } else { System.out.println(“Directory of “ + dirname); String d[]=dir.list(); for (int i=0; i<d.length;i++) { System.out.println(d[i]); } } } } Þï¢î𢠹«ó£è¤ó£ñ¤¬ù Þòè¢è¤ù£ô¢ ï£ñ¢ âï¢î Subdirectory-ò¤ù¢ ªðòó¤¬ùè¢ ªè£´î¢î¤¼è¢è¤ù¢«ø£«ñ£, Üî¤ô¢ à÷¢÷ ܬù file-è¬÷»ñ¢ display ªêò¢¶ ªè£´è¢°ñ¢. «ñ½ñ¢ âù¢ù file name ªè£´î¢î¤¼è¢è¤ù¢«ø£«ñ£ Üï¢î file- ù¬ð¢ ðø¢ø¤ò º¿¬ñò£ù îèõô¢è¬÷ ªðø¢Áî¢î¼ñ¢. main ( ) function- ù¢ Ýóñ¢ðî¢î¤ô¢ ºîô¤ô¢ String dirname=“india”; String filename=“store.java”; âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þî¤ô¢ india âù¢ð¶ Subdirectory, åù¢ø¤ù¢ ªðòó£°ñ¢. Þîø¢°ð¢ðî¤ô¢ ï¦é¢è÷¢ â颰 Þï¢î ¹«ó£è¤ó£ñ¤¬ù Þòè¢è𢠫ð£è¤ù¢ø¦ó¢è«÷£ Üî¤ô¢ à÷¢÷ sub directory-ò¤ù¢ ªðòó¤¬ùè¢ ªè£´î¢¶è¢ ªè£÷¢Àé¢è÷¢. ܶ «ð£ô«õ store.java âù¢ð¶ ªõ¼ñ¢ â´î¢¶è¢è£ì¢«ì. «õÁ å¼ file ªðòó¤¬ùè¢ ªè£´î¢¶è¢ ªè£÷¢Àé¢è÷¢. File myfile=new File(dirname, filename); âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þï¢î File âù¢Âñ¢ class-ô¢ î£ù¢ File operation êñ¢ðï¢îð¢ðì¢ì ܬù function-èÀñ¢ Þ¼è¢è¤ù¢øù.
- 142. 142 Þð¢ªð£¿¶ india âù¢Âñ¢ Subdirectory-ô¢ à÷¢÷ store.java âÂñ¢ file-ù¢ ܬù îèõô¢èÀñ¢ º¿¬ñò£è myfile âù¢Âñ¢ object -ù¢ à÷¢ õõ¤ì¢ìù. Þ颰 myfile.getName( ) âù¢Á ªè£´è¢°ñ¢ ªð£¿¶ file-ù¢ ªðòó¢ 褬ìè¢è¤ù¢ø¶. myfile.isDirectory( ) âù¢Á ªè£´è袰ñ¢ªð£¿¶ file âï¢î Subdirectory-ò¤ô¢ Þ¼è¢è¤ù¢ø¶ âù¢ð¶ ªîó¤»ñ¢. myfile.isFile()âù¢Á ªè£´î¢î£ô¢ ï£ñ¢ ªè£´î¢î¤¼è¢°ñ¢ ªðòó¤ô¢ Þ¼ð¢ð¶ file î£ù£ Üô¢ô¶ Þô¢¬ôò£ âù¢ðî¬ùî¢ ªîó¤ï¢¶è¢ ªè£÷¢÷ô£ñ¢. myfile.getpath() âù¢Á ªè£´è¢°ñ¢ file-ù¢ º¿ path 褬ìè¢è¤ù¢ø¶. myfile.canRead( ) âù¢Á ªè£´è¢°ñ¢ ªð£¿¶ file -¬ù ð®è¢è º®»ñ£ Üô¢ô¶ º®ò£î âù¢ð¶ ªîó¤»ñ¢. Ü«î«ð£ô¢ myfile.canWrite()âù¢Á ªè£´è¢°ñ¢ªð£¿¶ file-ù¤ô¢ îèõô¢è¬÷ ¹î¤î£è â¿î º®»ñ£ Üô¢ô¶ º®ò£î£ âù¢ð¶ ªîó¤»ñ¢. myfile.lastModified( ); âù¢Á ªè£´è¢°ñ¢ªð£¿¶ file- ¬ù è¬ìê¤ò£è ï£ñ¢ âï¢î «îî¤ ñø¢Áñ¢ «ïóî¢î¤ô¢ ðòù¢ð´î¢î¤«ù£ñ¢ âù¢ø îèõô¢è÷¢ 褬ìè¢è¤ù¢øù. ܴ File dir=new File(dirname); âù¢Á ªè£´î¢î¤¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. ï£ñ¢ ªè£´î¢î¤¼è¢°ñ¢ ªðòó¤ô¢ å¼ Subdirectory-ò¤¼ð¢ð¤ù¢ dir.isDirectory( ) function Ýù¶ true âù¢Á ªè£´è¢°ñ¢. Üð¢ªð£¿¶ if condition- ù¤ô¢ else ð°î¤ Þò颰ñ¢. Ü颰 String d[ ] = dir.list( ); âù¢Á ªè£´î¢î¤¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þîù¢ Íôñ¢ ï£ñ¢ ªè£´î¢î Sub directoryò¤ù¢ ܬù file-è÷¤ù¢ ªðòó¢èÀñ¢ d âù¢Âñ¢ String array ò¤ô¢ ðî¤è¤ù¢øù. Üõø¢¬ø loop-ù¢ Íôñ¢ ï£ñ¢ display ªêò¢¶ ªè£÷¢è¤ù¢«ø£ñ¢. ðì‹ðì‹ðì‹ðì‹ðì‹ 8.1
- 143. 143 Listing 8.2 import java.io.*; class LineByLine { public static void main(String args[]) throws FileNotFoundException { String filename=”FileQuery.java”; FileInputStream f=new FileInputStream(filename); LineNumberInputStream filestream=new LineNumberInputStream(f); try { int c; System.out.print(“Line 1:”); while ((c=filestream.read())!= -1) { System.out.print((char)c); if (c==’n’) { System.out.print(“Line “ + (filestream.getLineNumber()+1) + “:”); } } }catch(IOException e) { System.out.println(“Can’t open stream!”); } } }
- 144. 144 Þï¢î ¹«ó£è¤ó£ñ¤ù¤ô¢ å¼ text file-ô¢ à÷¢÷ ܬù õó¤è¬÷»ñ¢ read ªêò¢¶ display ªêò¢õîø¢°ð¢ ¹«ó£è¤ó£ñ¢ â¿îð¢ð좴÷¢÷¶. ºîô¤ô¢ main( ) function ù¤ù¢ ªî£ìó¢ê¢ê¤ò£è throws FileNotFoundException âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þîù¢ Íôñ¢ ï£ñ¢ ªè£´è¢è¤ù¢ø file Ýù¶ êó¤ò£è open Ýèõ¤ô¢¬ô ªòù¤ô¢ Can’t open Stream; âù¢Á error õ¼ñ£Á ¹«ó£è¤ó£ñ¤ù¢ è¬ìê¤ò¤ô¢ exception ܬñè¢èð¢ð좮¼è¢è¤ù¢ø¶ File IntputStream f= new FileInputStream(filename); LineNumberInputStream filestream = new LIneInputStream(f); âù¢Á ªè£´è¢èð¢ð좮¼ð¢ð¬îè¢ class Ýù¶ å¼ file-ô¢ à÷¢÷ â¿î¢¶è¢è¬÷ read ªêò¢õîø¢è¢° àî¾è¤ù¢ø¶. ï£ñ¢ Þ颰 FileQuery.java âù¢Âñ¢ textfile-ô¢ à÷¢÷ îèõô¢è¬÷ read ªêò¢ò Þ¼è¢è¤ù¢«ø£ñ¢. ï¦é¢è÷¢ àé¢èÀ袰 «õí¢®ò file-è÷¤ù¢ªðòó¤¬ùè¢ Þ颰 ªè£´î¢¶è¢ ªè£÷¢Àé¢è÷¢. LineNumberInput StreamÝù¶ file-ô¢ îø¢ªð£¿¶ ï£ñ¢ âï¢î Line-ô¢ Þ¼è¢è¤ù¢«ø£ñ¢ âù¢ø îèõ¬ô𢠪ðø¢Áî¢îóè¢Ã®ò getLineNumber( ) function Þ¼ð¢ðîù£ô¢ ðòù¢ð´î¢¶è¤ù¢«ø£ñ¢. while((c=filestream.read())!=-1) âù¢Á ªè£´î¢î¤¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þ颰 read( ) function Ýù¶ file-ô¢ à÷¢÷ åõ¢ªõ£Á â¿î¢î£è read ªêò¢¶ ªè£´è¢è¤ù¢ø¶. å¼ â¿î¢¶ read ªêò¢òð¢ðì¢ì¾ìù¢ file pointer Ýù¶ Ü´î¢î â¿î¢î¤ø¢° î£ù£è ªêù¢Á õ¤´ñ¢. âð¢ªð£¿¶ end of file-ø¢è¢° õ¼è¤ù¢«ø£«ñ£ Üð¢ªð£¿¶ -1 âù¢ø ñî¤ð¢ð¤¬ù𢠪ðÁ«õ£ñ¢. Üð¢ªð£¿¶ loop-¬ù õ¤ì¢´ ªõ÷¤ò¤ô¢ õ õ¤´«õ£ñ¢. loop-ù¢ à÷¢ System.out.print ((char)c); âù¢Á ªè£´ð¢ðîù¢Íôñ¢ åõ¢ªõ£Á â¿î¢î£è display Ýè¤ù¢ø¶. Listing 8.3 import java.io.*; class copycharacters { public static void main(String args[]) { File infile=new File(“FileQuery.java”); File outfile=new File(“output.dat”); FileReader ins=null;
- 145. 145 FileWriter outs=null; try { ins=new FileReader(infile); outs=new FileWriter(outfile); int ch; while ((ch=ins.read())!=-1) { outs.write(ch); } } catch(IOException e) { System.out.println(e); System.exit(-1); } finally { try { ins.close(); outs.close(); } catch(IOException e) {} } } } Þï¢î ¹«ó£è¤ó£ñ£ù¶ ãø¢è¢ªèù«õ Þ¼è¢è¤ù¢ø å¼ Text File-ô¢ à÷¢÷ îèõô¢è¬÷ read ªêò¢¶ ¹î¤î£è å¼ file-¬ù à¼õ£è¢è¤ ÜîÂ÷¢ copy ªêò¢»ñ¢ð®è¢° â¿îð¢ð좮¼è¢è¤ù¢ø¶. File infile=new File(“FileQuery.java”); File outfile=new File(“Output.dat”); Þ颰 FileQuery.java âù¢Âñ¢ file-ô¤ô¢ à÷¢÷ îèõô¢è÷¢ read ªêò¢òð¢ð좴 output.dat âù¢Âñ¢ ¹î¤ò file à¼õ£è¢èð¢ð좴 ÜîÂ÷¢ ðî¤òð¢ðì Þ¼è¢è¤ù¢ø¶.
- 146. 146 âù«õ FileReader ñø¢Áñ¢ FileWriter Ýè¤ò Class-è÷¤ù¢ object-è÷¢ ins, outs âù¢Á à¼õ£è¢èð¢ð좴 Þ¼è¢è¤ù¢øù. while((ch=ins.read( ))!=-1) âù¢Á loop ܬñè¢èð¢ð좮¼è¢è¤ù¢ø¶. Þîù¢ Íôñ¢ end of file õ¼ñ¢ õ¬ó åõ¢ªõ£Á â¿î¢îè¢è÷£è read ªêò¢òð¢ð좴 outs.write(ch); âù¢ø function àð«ò£è¤ð¢ð좴 åõ¢ªõ£Á â¿î¢î£è output.dat âÂñ¢ file -ô¢ â¿îð¢ð´è¤ù¢ø¶. finally âù¢ø function åù¢Á â¿îð¢ð좮¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Þ¶ Java õ¤ô¢ Þ¼è¢è¤ù¢ø destructor function Ý°ñ¢. ¹«ó£è¤ó£ñ¢ º®»ñ¢ ªð£¿¶ î£ù£è Þò颰ñ¢. ÞîÂñ¢ ins.close(); outs.close(); Ýè¤ò file-è÷¢ Close ªêò¢òð¢ ð좮¼è¢è¤ù¢øù.
- 147. 147 Üî¢î¤ò£òñ¢Üî¢î¤ò£òñ¢Üî¢î¤ò£òñ¢Üî¢î¤ò£òñ¢Üî¢î¤ò£òñ¢ 9. Calander - ¹«ó£è¤ó£ñ¢¹«ó£è¤ó£ñ¢¹«ó£è¤ó£ñ¢¹«ó£è¤ó£ñ¢¹«ó£è¤ó£ñ¢ Þï¢î Üî¢î¤ò£òî¢î¤ô¢ Calender ¹«ó£è¤ó£ñ¢ åù¢Á õ¤÷è¢èð¢ð좴÷¢÷¶. Þî¬ù Üø¤ï¢¶ ªè£÷¢õîù¢ Íôñ¢ àé¢è÷£ô¢ ²ôðñ£è âî¢î¬èò ¹«ó£è¤ó£ñ¢è¬÷»ñ¢ Java -õ¤ô¢ â¿î º®»ñ¢. Þï¢î ¹«ó£è¤ó£ñ¢ å¼ Applet Ý°ñ¢. Þî¤ô¢ GridBagLayout ðòù¢ð´î¢îð¢ ð좮¼è¢è¤ù¢ø¶. l_month, c_month, d_year, txt_year, up, down âù¢Á ÝÁ Object è¬÷ õó¤¬êò£è å«ó row õ¤ù¤ô¢ align ªêò¢õîø¢° GridbagLayout ðòù¢ð´î¢îð¢ð좮¼è¢è¤ù¢ø¶. ðì‹ðì‹ðì‹ðì‹ðì‹ 9.1 Listing 9.1 import java.awt.*; import java.applet.Applet; import java.util.*; public class calender extends Applet { Date mydate;
- 148. 148 GridBagLayout gl=new GridBagLayout(); GridBagConstraints gc=new GridBagConstraints(); void assign (GridBagConstraints abc,int gx,int gy,int gw,int gh,int wx,int wy,int fi,int ga) { abc.gridx=gx; abc.gridy=gy; abc.gridwidth=gw; abc.gridheight=gh; abc.weightx=wx; abc.weighty=wy; abc.fill=fi; abc.anchor=ga; } Choice c_month=new Choice(); Label l_month=new Label(“Month”); Label l_year=new Label(“year”); TextField txt_year=new TextField(4); String[] a_month={“January”,”February”,”March”,”April”, ”May”,”June”,”July”,”August”,“September”,”October”,”November”,”December”}; String[] a_days={“Sun”,”Mon”,”Tue”,”Wed”,”Thur”, ”Fri”,”Sat”}; String[] a_dates={“1”,”2",”3",”4",”5",”6",”7",”8",”9",”10", “11”,”12",”13",”14",”15",”16",”17",”18",”19",”20",“21”,”22",”23", ”24",”25",”26",”27",”28",”29",”30",”31"}; int[] x_row={100,150,200,250,300,350,400}; int[] x_col={100,150,200,250,300,350,400}; Button up,down; int my_count,my_month,my_year,my_day,txin; public void init() { mydate=new Date(); for(int i=0;i<a_month.length;i++) {
- 149. 149 c_month.addItem(a_month[i]); } up=new Button(“>”); down=new Button(“<“); setLayout(gl); assign(gc,0,0,1,1,100,100,GridBagConstraints.NONE, GridBagConstraints.NORTHEAST); gl.setConstraints(l_month,gc); add(l_month); assign(gc,1,0,1,1,100,100,GridBagConstraints.NONE, GridBagConstraints.NORTHEAST); gl.setConstraints(c_month,gc); add(c_month); assign(gc,2,0,1,1,100,100,GridBagConstraints.NONE, GridBagConstraints.NORTHEAST); gl.setConstraints(l_year,gc); add(l_year); assign(gc,4,0,1,1,100,100,GridBagConstraints.NONE, GridBagConstraints.NORTHEAST); gl.setConstraints(txt_year,gc); add(txt_year); int year=mydate.getYear()+1900; txt_year.setText(“”+year); txt_year.setEditable(false); assign(gc,5,0,1,1,100,100,GridBagConstraints.NONE, GridBagConstraints.NORTHEAST); gl.setConstraints(up,gc);
- 150. 150 add(up); assign(gc,3,0,1,1,100,100,GridBagConstraints.NONE, GridBagConstraints.NORTHEAST); gl.setConstraints(down,gc); add(down); c_month.select(a_month[mydate.getMonth()]); my_month=mydate.getMonth(); if(my_month==0) my_count=31; else if(my_month==1) { int ef=Integer.parseInt(txt_year.getText()); if(ef%4==0) my_count=29; else my_count=28; } else if(my_month==2) my_count=31; else if(my_month==3) my_count=30; else if(my_month==4) my_count=31; else if(my_month==5) my_count=30; else if(my_month==6) my_count=31; else if(my_month==7) my_count=31; else if(my_month==8) my_count=30;
- 151. 151 else if(my_month==9) my_count=31; else if(my_month==10) my_count=30; else if(my_month==11) my_count=31; repaint(); } public void paint(Graphics g) { my_day=1; int ab=Integer.parseInt(txt_year.getText()); my_year=ab-1900; mydate.setDate(my_day); mydate.setYear(my_year); mydate.setMonth(my_month); for(int i=0;i<a_days.length;i++) { g.drawString(a_days[i],x_col[i],75); } int x=mydate.getDay(); int y=0; for(int j=0;j<my_count;j++) { g.drawString(a_dates[j],x_col[x],x_row[y]); x++; if (x>6) { y++; x=0; } } }
- 152. 152 public boolean action(Event evt,Object arg) { if(evt.target instanceof Choice) { String lab=(String)arg; if (lab==”January”) { my_month=0; my_count=31; setBackground(Color.red); } else if(lab==”February”) { intbc=Integer.parseInt(txt_year.getText()); if(bc%4==0) { my_month=1; my_count=29; } else { my_month=1; my_count=28; setBackground(Color.pink); } } else if(lab==”March”) { my_month=2; my_count=31; setBackground(Color.cyan); }Java-19
- 155. 155 } else { if(my_month==1) my_count=28; } repaint(); return true; } else if(evt.target.equals(down)) { txin=Integer.parseInt(txt_year.getText()); txin—; txt_year.setText(““+txin); if(txin%4==0) { if(my_month==1) my_count=29; } else { if(my_month==1) my_count=28; } repaint(); return true; } else return true; } } ¹«ó£è¤ó£ñ¤ù¢ Ýóñ¢ðî¢î¤ô¢ a_month, a_dates, x_row, x_col âù¢Á array-è÷¢ à÷¢÷ù. Þõø¢ø¤ô¢ a_month âù¢ø array-ò¤ô¢ January, February, March âù¢Á ñ£îé¢è÷¤ù¢ ªðòó¢è÷¢ ðî¤òð¢ð좮¼è¢è¤ù¢øù. a_days âù¢Âñ¢ array ò¤ô¢ sun, Mon, tue, âù¢Á ï£÷¢è÷¤ù¢ ªðòó¢è¬÷ ðî¤òð¢ð좮¼è¢è¤ù¢øù. a_dates âù¢Âñ¢ array
- 156. 156 ò¤ô¢ 1,2,3,..... âù¢Á ï£ì¢è÷¤ù¢ ªðòó¢è¬÷ ðî¤òð¢ð좮¼è¢è¤ù¢øù. x_row ñø¢Áñ¢ x_col ºîô¤ò array ò¤ô¢ ïñ¢º¬ìò ï£ì¢è÷¢ ñø¢Áñ¢ «îî¤è÷¢ âîï¢î Þìé¢è÷¤ô¢ õó«õí¢´ñ¢ âù¢Á °ø¤ð¢ðî£è x ñø¢Áñ¢ y coordinate ñî¤ð¢¹è÷¢ ªè£´è¢èð¢ð좴÷¢÷ù. Þï¢î ¹«ó£è¤ó£ñ¤ù¢ àò¤ó¢ï£®«ò Date class-ô¢ î£ù¢ Þ¼è¢è¤ù¢ø¶. mydate=new Date ( ); âù¢Á ªè£´î¢¶ mydate âù¢ø ªðòó¤ô¢ å¼ Date object-®¬ù à¼õ£è¢è¤è¢ ªè£÷¢Àè¤ù¢«ø££ñ¢. ªð£¶õ£è Date object à¼õ£°ñ¢ ªð£¿¶ Üî¤ô¢ îø¢ªð£¿¶ System-î¢î¤ô¢ âù¢ù date Þ¼è¢è¤ù¢ø«î£ Üï¢î ñî¤ð¢¹ õ ðî¤ï¢¶ õ¤´ñ¢. Date class-ô¢ Þ¼è¢è¤ù¢ø getDate( ) function Íôñ¢ âù¢ù ï£÷¢ îø¢ªð£¿¶ object-®ô¢ Þ¼è¢è¤ù¢ø¶ âù¢ðî¬ù ªîó¤ï¢¶ ªè£÷¢÷ Þò½ñ¢. ܶ«ð£ô¢ getMonth() âù¢ø function Íôñ¢ object-®ù¤ô¢ îø¢ªð£¿¶ âù¢ù ñ£îñ¢ Þ¼è¢è¤ù¢ø¶ âù¢ðî¬ù Üø¤ï¢¶ ªè£÷¢÷ô£ñ¢. 0 õ¤ô¤¼ï¢¶ ñ£îé¢è÷¢ èíè¢è¤ìð¢ð´è¤ù¢øù. Üî£õ¶ 0 âù¢ø££ô¢ January, 1âù¢ø£ô¢ February âù¢ø õ¬èò¤ô¢ ޼袰ñ¢. getYear() function Íôñ¢ object-®ô¢ Þ¼è¢è¤ù¢ø õ¼ìî¢î¤ù¢ ñî¤ð¢ð¤¬ù𢠪ðø¢Áè¢ ªè£÷¢÷ô£ñ¢. Þ颰 2002 âù¢ø õ¼ìñ¢ Þ¼ð¢ð¤ù¢ 102 âù¢ø ñî¤ð¢¹ î£ù¢ õ¼ñ¢. Üî£õ¶ 1900 âù¢ø õ¼ìî¢î¤ô¤¼ï¢¶ èí袪è´î¢¶è¢ ªè£÷¢÷ð´è¤ù¢ø¶ âù¢Á ªð£¼÷¢. getDay() âù¢ø function ¬ùð¢ ðòù¢ð´î¢î¤ object-®ô¢ Þ¼è¢è¤ù¢ø «îî¤ò£ù¶ âï¢î è¤ö¬ñò¤ô¢ õ¼è¤ù¢ø¶ âù¢ðî¬ù Üø¤ï¢¶ ªè£÷¢÷ô£ñ¢. ë£ò¤ø¢Áè¢è¤ö¬ñ âù¢ø£ô¢ 0 âù¢Á õ¼ñ¢. î¤é¢è÷¢ è¤ö¬ñªòù¢ø£ô¢ 1 âù¢ø õ¬èò¤ô¢ ñî¤ð¢¹è÷¢ õ¼ñ¢ âù¢ðî¬ù 郎ùõ¤ô¢ ªè£÷¢Àé¢è÷¢. init( ) function-ô¢ ºîô¤ô¢ Date object-®¬ù à¼õ£è¢è¤òð¢ ð¤ù¢¹ for loop åù¢ø¤¬ù ܬñ Üîù¢ Íôñ¢ c_month âù¢Âñ¢ Choice -ô¢ a_month âù¢Âñ¢ array -ò¤ô¢ Þ¼è¢è¤ù¢ø ñ£îé¢è÷¤ù¢ ªðòó¢è¬÷ add ªêò¢¶ ªè£÷¢è¤ù¢«ø£ñ¢. ܴ up, down âù¢Á Þóí¢´ push Button -è¬÷ à¼õ£è¢è¤è¢ ªè£÷¢è¤ù¢«ø£ñ¢. ¹«ó£è¤ó£ñ¤ù¢ Ýóñ¢ðî¢î¤ô¢ gl âù¢ø ªðòó¤ô¢ GridBagLayout åù¢ø¤¬ù»ñ¢, gc âù¢ø ªðòó¤ô¢ GridBagConstraint åù¢ø¤¬ù»ñ¢ à¼õ£è¢è¤ò¤¼è¢è¤ù¢«ø£ñ¢ Üô¢ôõ£? Üõø¢¬øè¢ ªè£í¢´ assign âù¢Á ï£ñ¢ â¿î¤ò¤¼è¢°ñ¢ function õö¤ò£è åõ¢ªõ£Á object Ýè ªè£´î¢¶ add ªêò¢¶ ªè£÷¢è¤ù¢«ø£ñ¢.
- 157. 157 object -è÷¢ ܬùî»ñ¢ add ªêò¢îð¤ø° îø¢ªð£¿¶ mydate object-®ù¢ year- ô¢ âù¢ù ñî¤ð¢¹ Þ¼è¢è¤ù¢ø«î£ ÜîÂìù¢ 1900 âù¢ø ñî¤ð¢ð¤¬ùè¢ Ã좮 àí¢¬ñò£ù «îî¤ò£ù txt_year âù¢Âñ¢ object-®ù¤ô¢ display ªêò¢¶ ªè£÷¢è¤ù¢«ø£ñ¢. ܴ mydate.getMonth ( ) âù¢ø function -ù¤¬ùð¢ ðòù¢ð´î¢î¤ object-®ô¢ îø¢ªð£¿¶ âù¢ù ñ£îñ¢ Þ¼è¢è¤ù¢ø¶ âù¢ðî¬ù èí¢´ð¤®î¢¶ Üîù¢ð® åõ¢ªõ£¼ ñ£îî¢î¤ø¢è¢°ñ¢ âî¢î¬ù ï£÷¢è÷¢ âù¢Á õó¤¬êò£è if condition Íôñ¢ assign ªêò¢¶ ªè£÷¢è¤ù¢«ø£ñ¢. Þ¼î¤ò¤ô¢ repaint( ) âù¢Á ªè£´è¢°ñ¢ªð£¿¶ paint function Þò颰è¤ù¢ø¶. paint( ) function-ù¤ô¢ ºîô¤ô¢ my_day=1; âù¢Á ªè£´î¢î¤¼ð¢ð¬îè¢ èõù¤»é¢è÷¢. Üî£õ¶ ï£ñ¢ âï¢î õ¼ìî¢î¤Â¬ìò ñø¢Áñ¢ âï¢î °ø¤ð¢ð¤ì¢ì ñ£îî¢î¤ù¢ Calendar -ø¤¬ù display ªêò¢ò «õí¢´ñ¢ âù¢Á 郎ùè¢è¤ù¢«ø£«ñ£ Üï¢î ñ£îî¢î¤ù¢ ºîô¢ «îî¤ò£ù¶ âï¢î è¤ö¬ñò¤ô¢ Ýóñ¢ðñ£è¤ø¶ âù¢ðî¬ù Üø¤ï¢¶ ªè£÷¢÷ «õí¢´ñ¢. âù«õ ï£ñ£è«õ my_day âù¢Âñ¢ Variable, âù¢ø ñî¤ð¢ð¤¬ù ð ªêò¢¶ ªè£÷¢è¤ù¢«ø£ñ¢. my_month, my_year Ýè¤ò variable-è÷¤ø¢è¢° c_month ñø¢Áñ¢ txt_year Ýè¤ò object-è÷¤ô¢ îø¢ªð£¿¶ âù¢ù ñî¤ð¢¹ Þ¼è¢è¤ù¢ø«î£ Üî¬ù𢠪ðø¢Áè¢ ªè£÷¢Àè¤ù¢«ø£ñ¢. Þï¢î my_day, my_month, my_year Ýè¤ò variable-è÷¤ô¢ ޼袰ñ¢ Date ñî¤ð¢¹è¬÷ º¬ø«ò SetDate( ), setMonth( ), SetYear( ) Ýè¤ò Date class -ù¢ method function õö¤ò£è ðªêò¢¶ ªè£÷¢è¤ù¢«ø£ñ¢. îø¢ªð£¿¶ ð ªêò¢òð¢ðì¢ì, ñ£îî¢î¤ù¢ ºîô¢ «îî¤ò£ù¶ âï¢î è¤ö¬ñò¤ô¢ õ¼è¤ù¢ø¶ âù¢ðî¬ù Üø¤ï¢¶ ªè£÷¢õîø¢è¢è£è x=mydate.getDay ( ); âù¢ø function õö¤ò£è Üø¤ï¢¶ ªè£÷¢è¤ù¢«ø£ñ¢. â´î¢¶è¢è£ì¢ì£è Þï¢î function Ýù¶ 3 âù¢ø ñî¤ð¢ð¤¬ùè¢ ªè£´î¢î£ô¢ ܶ wednesday âù¢ø è¤ö¬ñò¤¬ùè¢ °ø¤è¢è¤ù¢ø¶. ï£ñ¢ ãø¢è¢ªèù«õ x_col, y_col Ýè¤ò Array-è÷¤ô¢ ðî¤ï¢¶ ¬õî¢î¤¼è¢è¤ù¢ø ñî¤ð¢¹èÀ袰 ãø¢ø£ø¢«ð£ô¢ è¤ö¬ñè¬÷ loop-ù¢ Íôñ¢ display ªêò¢¶ Þ¼è¢è¤ù¢«ø£ñ¢. Þð¢ªð£¿¶ «îî¤è¬÷ õó¤¬êò£ò¢ x-ô¢ âù¢ù ñî¤ð¢¹ Þ¼è¢è¤ù¢ø«î£ Üî¤ô¤¼ï¢¶ loop-ù¢ õö¤ò£è display ªêò¢è¤ù¢«ø£ñ¢. x-ù¢ ñî¤ð¢¬ð Ãì¢®è¢ ªè£í¢«ì õ¼è¤ù¢«ø£ñ¢. x-ù¢ ñî¤ð¢¹ 6 -袰 «ñô¢ ªêô¢½ñ¢ ªð£¿¶ Üî¬ù 0 âù¢ø ñî¤ð¢ð£è ñø¢ø¤ õ¤ì¢´, y-ù¢ ñî¤ð¢ð¤ô¢ åù¢ø¤¬ùè¢ Ãì¢®è¢ ªè£÷¢Àè¤ù¢«ø£ñ¢. Þñ¢º¬øò¤ô¢ ïñ袰 Calendar 褬ìè¢è¤ù¢ø¶. «ñ½ñ¢ Action event-ù¢ õö¤ò£è âð¢ªð£¿ªîô¢ô£ñ¢ ï£ñ¢c_month, up, downÝè¤ò
- 158. 158