JAVA

Java is an object-oriented programming language developed by Sun Microsystems. Java language was designed to be small, simple, and portable across platforms and operating systems, both at the source and at the binary level, which means that Java programs (applets and applications) can run on any machine that has the Java virtual machine installed.

Java is Platform independent, Platform independence means, the ability of a program to move easily from one computer system to another-is one of the most significant advantages that Java has over other programming languages, particularly if your software needs to run on many different platforms.

The Java language was developed at Sun Microsystems in 1991 as part of a research project to develop software for consumer electronics devices. Java's rapidly growing popularity is due to the Web. But Java's inherent power does not come from the fact that it is a Web programming language. The talented software engineers at Sun, in bringing Java to the Web, have elegantly solved a much broader and more significant problem-how to develop network-capable windowing software that will run on almost any 32-bit computer and operating system.

A software developer writes programs in the Java language that use predefined software packages of the Java API. The developer compiles his or her programs using the Java compiler. This results in what is known as compiled bytecode. Bytecode is in a form that can be executed on the Java virtual machine, the core of the Java runtime system. You can think of the virtual machine as a microprocessor that is implemented in software and runs using the capabilities provided by your operating system and computer hardware. Since the Java virtual machine is not a real microprocessor, the Java bytecode is interpreted, rather than executed directly in the native machine instructions of the host computer.

Java is exceptionally well suited to distributed networking applications because of its built-in networking support and the runtime system's capability to dynamically load Java bytecode across the network. Java also provides the capability to dynamically utilize new content and protocol handling software. The HotJava browser, written in Java, is an excellent example of Java's distributed networking capabilities.

The Java API provides full support of multithreaded programming. Multithreaded programs can be developed in a single, consistent manner, independent of the vagaries of the host operating system interface.

Java classes and objects directly support the object-oriented concepts of encapsulation, inheritance, messages and methods, and data hiding. Java interfaces provide support for multiple inheritance and polymorphism. The Java language retains all the benefits of object-oriented programming without the performance impacts associated with pure object languages, such as Smalltalk.

The Java API provides extensive support of windowing and graphical user interface development without the complexities associated with maintaining multiple window class libraries. Several visual programming tools have been developed for Java.