java over view

Table of Contents Introduction to Java About Java Platform Independence Java Virtual Machine     Object Oriented Programming Java Features  Java Applications Getting Started with Java Java Architecture Compiling and Running an Application Java Development Kit javadoc JAR Files PATH and CLASSPATH Introduction to Java 1.5 Basic Language Elements Keywords Comments Variable, Identifiers and Data Types Classes Objects Interface Instance Members Static Members Arrays Java Operators Java Operators Assignment operators Arithmetic operators Relational operators Logical operators Bitwise operators Compound operators Conditional operators Operator Precedence Java Control Statements Introduction to Control Statements Selection Statements Iteration Statements Transfer Statements Java Access Modifiers Introduction to Java Access Modifiers public access modifier private access modifier protected access modifier default access modifier Classes and Objects Class Variables – Static Fields Class Methods – Static Methods Instance Variables Final Variable, Methods and Classes Introduction to Java Objects Method Overloading Java Constructors Overloaded Constructors Constructor Chaining Object Serialization Introduction to Object Serialization Transient Fields and Serialization Input and Output Object Streams Java Class Inheritance Java Class Inheritance this and super keywords Java Object Casting Object Reference Type Casting instanceof Operator Abstract class and Interface Abstract Class in java Java Interface Polymorphism Java Method Overriding Java String Class String Class Creation of Strings String Equality String Functions Java toString() Method Java toString() Method Java String Comparison Compare String objects to determine Equality  Java StringBuffer StringBuffer Class Creation of StringBuffer's StringBuffer Functions Java Exception Handling Exceptions in Java Exception Classes Exception Statement Syntax Rules for try, catch and finally Blocks try, catch and finally Defining new Exceptions throw, throws statement Handling Multiple Exceptions Java Singleton Design Pattern Singleton Implementing the Singleton Pattern Java Threads Tutorial Introduction to Threads Thread Creation Thread Synchronization Synchronized Methods Synchronized Blocks Thread States Thread Priority Thread Scheduler Yielding Sleeping and Waking Up Waiting and Notifying Joining Deadlock Java Collections Framework Core Collection Interfaces Concrete Classes Standard utility methods and algorithms How are Collections Used Java ArrayList Java LinkedList Java TreeSet Java HashMap Java Vector Java HashTable Java HashSet Java Date Util Java Date API Java Date Source Code Java Swing Tutorial Intoduction to Java Swing JFrame JInternalFrame JWindow JOptionPane JLabel JTextField JPasswordField JTextArea JButton JRadioButton JCheckBox JComboBox JList JTabbedPane JMenuBar Scrollable JPopupMenu JToolBar BorderLayout FlowLayout GridLayout GridBagLayout Java Look and Feel Swing Calculator Swing Address Book

Java programming language was originally developed by Sun Microsystems, which was initiated by James Gosling and released in 1995 as core component of Sun Microsystems.s Java platform (Java 1.0 [J2SE]).

As of December 08 the latest release of the Java Standard Edition is 6 (J2SE). With the advancement of Java and its wide spread 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

Java is:

• 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.
• Secure : With Java's secure feature it enables to develop virus-free, tamper-free systems. 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 Java runtime system.
• Portable :being architectural neutral and having no implementation dependent aspects of the specification makes Java portable. Compiler and Java is written in ANSI C with a clean portability boundary which is a POSIX subset.
• Robust :Java makes an effort to eliminate error prone situations by emphasizing mainly on compile time error checking and runtime checking.
• Multi-threaded : With Java's multi-threaded 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 light weight process.
• 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.

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 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.

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.

Tools you will need:

For performing the examples discussed in this tutorial, you will need a Pentium 200-MHz computer with a minimum of 64 MB of RAM (128 MB of RAM recommended).

You also will need the following softwares:

• Linux 7.1 or Windows 95/98/2000/XP operating system.
• Java JDK 5
• Microsoft Notepad or any other text editor

This tutorial will provide the necessary skills to create GUI, networking, and Web applications using Java.

Try It Option:

We have provided you an option to compile and execute available code online. Just click on Try itbutton avaiable at top-right corner of the code window to compile and execute available code. There are certain examples which can not be executed online, so we have skipped those examples.

public class MyFirstJavaProgram {

    public static void main(String []args) {
       System.out.println("Hello World");
    }
} 

There may be a case that you do not see the result of the compiled/executed code, in such case you can re-try to compile and execute the code using execute button available in compliation pop-up window.