Chapter 1 java
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- Java was originally developed by Sun Microsystems in the early 1990s and was designed to be a simple, object-oriented, robust, secure, portable, high-performance, multithreaded and dynamic language. - Key features include being platform independent via bytecode, having a robust runtime environment in the Java Virtual Machine, and being object-oriented which makes Java code reusable and extensible. - Java tools include a JDK for development and a JRE for running programs, with the JRE containing the Java Virtual Machine to interpret bytecode and class libraries.
Chapter 1 java
- 2. Introduction • Java programming language was originally developed by Sun Microsystems which was initiated by James Gosling. • With the advancement of Java and its widespread popularity, multiple configurations were built to suite various types of platforms. Ex: J2EE for Enterprise Applications, J2ME for Mobile Applications. • Sun Microsystems has renamed the new J2 versions as Java SE, Java EE and Java ME, respectively. Java is guaranteed to be Write Once, Run Anywhere.
- 3. Java Features • Object Oriented: In Java, everything is an Object. Java can be easily extended since it is based on the Object model. • Platform independent: Unlike many other programming languages including C and C++, when Java is compiled, it is not compiled into platform specific machine, rather into platform independent byte code. This byte code is distributed over the web and interpreted by virtual Machine (JVM) on whichever platform it is being run. • Simple: Java is designed to be easy to learn. If you understand the basic concept of OOP, Java would be easy to master.
- 4. Continue.. • Secure: With Java's secure feature, it enables to develop virus-free. Authentication techniques are based on public-key encryption. • Architectural-neutral: Java compiler generates an architecture- neutral object file format, which makes the compiled code to be executable on many processors, with the presence of Java runtime system. • Portable: Being architectural-neutral and having no implementation dependent aspects of the specification makes Java portable.
- 5. Continue.. Robust: Java makes an effort to eliminate error prone situations by emphasizing mainly on compile time error checking and runtime checking. Multithreaded: With Java's multithreaded feature, it is possible to write programs that can do many tasks simultaneously. This design feature allows developers to construct smoothly running interactive applications. Interpreted: Java byte code is translated on the fly to native machine instructions and is not stored anywhere. The development process is more rapid and analytical since the linking is an incremental and lightweight process.
- 6. Continue.. High Performance: With the use of Just-In-Time compilers, Java enables high performance. Distributed: Java is designed for the distributed environment of the internet. Dynamic: Java is considered to be more dynamic than C or C++ since it is designed to adapt to an evolving environment. Java programs can carry extensive amount of run-time information that can be used to verify and resolve accesses to objects on run-time.
- 7. History of Java • James Gosling initiated the Java language project in June 1991 for use in one of his many set-top box projects. • The language, initially called Oak after an oak tree that stood outside Gosling's office, also went by the name Green and ended up later being renamed as Java, from a list of random words. • Sun released the first public implementation as Java 1.0 in 1995. It promised Write Once, Run Anywhere (WORA), providing no-cost run-times on popular platforms.
- 8. Continue.. • On 13 November 2006, Sun released much of Java as free and open source software under the terms of the GNU General Public License (GPL). • On 8 May 2007, Sun finished the process, making all of Java's core code free and open-source, aside from a small portion of code to which Sun did not hold the copyright.
- 9. Tools you need You will need the following software's: • Linux 7.1 or Windows 95/98/2000/XP/Visa/Seven or later operating system. • Java JDK • Microsoft Notepad or any other text editor
- 10. Java Virtual Machine (JVM) • The Java virtual machine (JVM) is a software implementation of a computer that executes programs like a real machine. The Java virtual machine is written specifically for a specific operating system, e.g., for Linux a special implementation is required as well as for Windows. Java programs are compiled by the Java compiler into bytecode. The Java virtual machine interprets this bytecode and executes the Java program.
- 11. Continue..
- 12. Java Runtime Environment vs. Java Development Kit A Java distribution typically comes in two flavors, the Java Runtime Environment (JRE) and the Java Development Kit (JDK). The Java runtime environment (JRE) consists of the JVM and the Java class libraries. Those contain the necessary functionality to start Java programs. The JDK additionally contains the development tools necessary to create Java programs. The JDK therefore consists of a JRE and development tools.
- 13. Thank You