Developing Applications with MySQL and Java for beginners
7 likes3,017 views
The document outlines the requirements and steps to create a phonebook application using Java and MySQL, including database setup, Java class structures, and key methods for adding, deleting, and listing contacts. It provides specific code snippets and explanations for various components, such as database connection, table creation, and command-line interaction. Additionally, it emphasizes an interactive learning approach and encourages feedback on best practices.
![Create PhonebookApp Class
Methods: main()
public static void main(String[] args) {
if (args == null || args.length == 0) {
printHelp();
return;
}
PhonebookApp phonebookApp = new PhonebookApp();
switch (args[0]) {
case "list" : phonebookApp.showList(); break;
case "add" : phonebookApp.add(args); break;
case "delete" : phonebookApp.delete(args); break;
default : printHelp();
}
}
9](https://image.slidesharecdn.com/d3vymxkyr6anoikfnrbg-signature-5f0b92e78a3eaae653d35e46a6d4c6ce5c9aeac2c01ce0eb209065c1f2b8a33d-poli-141211131748-conversion-gate02/85/Developing-Applications-with-MySQL-and-Java-for-beginners-9-320.jpg)
![Create PhonebookApp Class
Methods: printHelp()
static void printHelp() {
System.out.println("Usage: java PhonebookApp [OPTIONS]");
System.out.println("Options: add FIRST_NAME LAST_NAME EMAIL MOBILE");
System.out.println("Options: list");
System.out.println("Options: delete ID”);
}
10](https://image.slidesharecdn.com/d3vymxkyr6anoikfnrbg-signature-5f0b92e78a3eaae653d35e46a6d4c6ce5c9aeac2c01ce0eb209065c1f2b8a33d-poli-141211131748-conversion-gate02/85/Developing-Applications-with-MySQL-and-Java-for-beginners-10-320.jpg)
![Create PhonebookApp Class
Methods: add()
void add(String[] args) {
if (args.length != 5) {
System.out.println("Error: Wrong Usage!");
printHelp();
} else {
try {
con = DriverManager.getConnection(url, user, password);
pst = con.prepareStatement("INSERT INTO contact(first_name, last_name, email, mobile) value (?,?,?,?) ");
int index = 1;
pst.setString(index, args[index++]);
pst.setString(index, args[index++]);
pst.setString(index, args[index++]);
pst.setString(index, args[index++]);
pst.executeUpdate();
} catch (SQLException ex) {
Logger lgr = Logger.getLogger(this.getClass().getName());
lgr.log(Level.SEVERE, ex.getMessage(), ex);
} finally {
closeAllConnections();
}
}
}
12](https://image.slidesharecdn.com/d3vymxkyr6anoikfnrbg-signature-5f0b92e78a3eaae653d35e46a6d4c6ce5c9aeac2c01ce0eb209065c1f2b8a33d-poli-141211131748-conversion-gate02/85/Developing-Applications-with-MySQL-and-Java-for-beginners-12-320.jpg)
![Create PhonebookApp Class
Methods: delete()
void delete(String[] args) {
if (args.length != 2) {
System.out.println("Error: Wrong Usage!");
printHelp();
} else {
long id = Integer.parseInt(args[1]);
if (id < 1) {
System.out.println("Error: id is not valid!");
} else {
try {
con = DriverManager.getConnection(url, user, password);
pst = con.prepareStatement("DELETE FROM contact where id = ? ");
pst.setLong(1, id);
pst.executeUpdate();
} catch (SQLException ex) {
Logger lgr = Logger.getLogger(this.getClass().getName());
lgr.log(Level.SEVERE, ex.getMessage(), ex);
} finally {
closeAllConnections();
}
}
}
}
13](https://image.slidesharecdn.com/d3vymxkyr6anoikfnrbg-signature-5f0b92e78a3eaae653d35e46a6d4c6ce5c9aeac2c01ce0eb209065c1f2b8a33d-poli-141211131748-conversion-gate02/85/Developing-Applications-with-MySQL-and-Java-for-beginners-13-320.jpg)
Developing Applications with MySQL and Java for beginners
- 1. Saeid Zebardast @saeid http://about.me/saeid saeid.zebardast@gmail.com 1
- 2. Please Please Please Ask Questions As Much As You Like • This is not a lecture! - But an opportunity to learn from each other. - If you haven’t seen some of these frameworks, methods, etc. It is OK! - Let we know if you know ‣ Better ways ‣ Best practices ‣ My mistakes!
- 3. Requirements • Java (OpenJDK) • MySQL • MySQL Connector - JDBC (Java Database Connectivity) ‣ https://dev.mysql.com/downloads/connector/j/ • Text Editor • Command Line! 3
- 4. MySQL Data Definition • Create database - $ mysql -u root -p ‣ mysql> CREATE DATABASE phonebook_app; • Create database user - $ mysql -u root -p ‣ mysql> GRANT ALL PRIVILEGES on `phonebook_app`.* to `pb_app`@'127.0.0.1' identified by '123456'; • Create table - $ mysql -u pb_app -p phonebook_app ‣ mysql> CREATE TABLE `contact` ( `id` INT(11) UNSIGNED NOT NULL AUTO_INCREMENT, `first_name` VARCHAR(100), `last_name` VARCHAR(100), `email` VARCHAR(100), `mobile` VARCHAR(15), PRIMARY KEY (`id`) ); 4
- 5. Java Classes Contact • Contact - Fields ‣ long id ‣ String firstName ‣ String lastName ‣ String email ‣ String mobile - Methods ‣ Contact() ‣ Getters for all fields: getId(), getFirstName() and etc. 5
- 6. Java Classes PhonebookApp • PhonebookApp - Import java.sql.* and java.util.*; - Fields ‣ Connection con; ‣ PreparedStatement pst; ‣ ResultSet rs; ‣ String url; ‣ String user; ‣ String password; 6 - Methods ‣ PhonebookApp() ‣ main() ‣ printHelp() ‣ showList() ‣ add() ‣ delete() ‣ closeAllConnections()
- 7. Create Content Class public class Contact { private long id; private String firstName; private String lastName; private String email; private String mobile; Contact(long id, String firstName, String lastName, String email, String mobile) { this.id = id; this.firstName = firstName; this.lastName = lastName; this.email = email; this.mobile = mobile; } // getter here } 7
- 8. Create PhonebookApp Class Fields and Constructor public class PhonebookApp { Connection con; PreparedStatement pst; ResultSet rs; String url; String user; String password; PhonebookApp() { url = "jdbc:mysql://127.0.0.1:3306/phonebook_app"; user = "pb_app"; password = "123456"; } //write methods here } 8
- 9. Create PhonebookApp Class Methods: main() public static void main(String[] args) { if (args == null || args.length == 0) { printHelp(); return; } PhonebookApp phonebookApp = new PhonebookApp(); switch (args[0]) { case "list" : phonebookApp.showList(); break; case "add" : phonebookApp.add(args); break; case "delete" : phonebookApp.delete(args); break; default : printHelp(); } } 9
- 10. Create PhonebookApp Class Methods: printHelp() static void printHelp() { System.out.println("Usage: java PhonebookApp [OPTIONS]"); System.out.println("Options: add FIRST_NAME LAST_NAME EMAIL MOBILE"); System.out.println("Options: list"); System.out.println("Options: delete ID”); } 10
- 11. Create PhonebookApp Class Methods: showList() void showList() { List<Contact> contactList = new ArrayList<>(); try { con = DriverManager.getConnection(url, user, password); pst = con.prepareStatement("SELECT * FROM contact"); rs = pst.executeQuery(); while (rs.next()) { contactList.add(new Contact(rs.getLong("id"), rs.getString("first_name"), rs.getString("last_name"), rs.getString("email"), rs.getString("mobile"))); } if (contactList.size() > 0) { for (Contact contact : contactList) { System.out.println(contact.getId() + "-" + contact.getFirstName() + " " + contact.getLastName() + ": Email = '" + contact.getEmail() + "', Mobile = '" + contact.getMobile() + "'."); } } else { System.out.println("You don't have any contacts in your list!"); } } catch (SQLException ex) { Logger lgr = Logger.getLogger(this.getClass().getName()); lgr.log(Level.SEVERE, ex.getMessage(), ex); } finally { closeAllConnections(); } } 11
- 12. Create PhonebookApp Class Methods: add() void add(String[] args) { if (args.length != 5) { System.out.println("Error: Wrong Usage!"); printHelp(); } else { try { con = DriverManager.getConnection(url, user, password); pst = con.prepareStatement("INSERT INTO contact(first_name, last_name, email, mobile) value (?,?,?,?) "); int index = 1; pst.setString(index, args[index++]); pst.setString(index, args[index++]); pst.setString(index, args[index++]); pst.setString(index, args[index++]); pst.executeUpdate(); } catch (SQLException ex) { Logger lgr = Logger.getLogger(this.getClass().getName()); lgr.log(Level.SEVERE, ex.getMessage(), ex); } finally { closeAllConnections(); } } } 12
- 13. Create PhonebookApp Class Methods: delete() void delete(String[] args) { if (args.length != 2) { System.out.println("Error: Wrong Usage!"); printHelp(); } else { long id = Integer.parseInt(args[1]); if (id < 1) { System.out.println("Error: id is not valid!"); } else { try { con = DriverManager.getConnection(url, user, password); pst = con.prepareStatement("DELETE FROM contact where id = ? "); pst.setLong(1, id); pst.executeUpdate(); } catch (SQLException ex) { Logger lgr = Logger.getLogger(this.getClass().getName()); lgr.log(Level.SEVERE, ex.getMessage(), ex); } finally { closeAllConnections(); } } } } 13
- 14. Create PhonebookApp Class Methods: closeAllConnections() void closeAllConnections() { try { if (rs != null) { rs.close(); } if (pst != null) { pst.close(); } if (con != null) { con.close(); } } catch (SQLException ex) { Logger lgr = Logger.getLogger(this.getClass().getName()); lgr.log(Level.WARNING, ex.getMessage(), ex); } } 14
- 15. Compile and Run PhonebookApp • compile - javac PhonebookApp.java • run - java -cp .:lib/mysql-connector-java-5.1.34-bin.jar PhonebookApp - java -cp .:lib/mysql-connector-java-5.1.34-bin.jar PhonebookApp list - java -cp .:lib/mysql-connector-java-5.1.34-bin.jar PhonebookApp add myFirstName myLastName myEmail myMobile - java -cp .:lib/mysql-connector-java-5.1.34-bin.jar PhonebookApp delete 2 15
- 16. Read The F* Manual • RTFM - https://dev.mysql.com/doc/ - http://docs.oracle.com/javase/ • Java: The Really Big Index - http://docs.oracle.com/javase/tutorial/reallybigindex.html • MySQL Help - mysql> HELP; - mysql> HELP CONTENTS; - mysql> HELP SELECT; 16
- 17. Thank You