About JAVA

Java Programming Language was designed by “James Gosling” at Sun Microsystems in 1991.  This language was initially called “Oak” but was renamed “Java” in 1995.  It follows both the features of C and C++.

            Java Programming Language was very useful on Internet Programming.  Since, by this language we can easily transfer the information from server to the nodes through the network.  It provides active programs when we are viewing the passive data and self-executing programs.  Generally, in the case of network programs Security and Portability is the main active areas concern.   The Java Applet Programming provides such things.

            Java programs are classified into 2 types.

1.      Application Programs

2.      Applet Programs

An Application is a program run on the computer under the operating system of the computer.  This is similar to the other programming languages.

An Applet is an application designed to be transmitted over the Internet and executed by a Java-compatible Web browser.

Java Features/Buzz Words

a) Platform Independent: Java is a platform independent language.  Once we create the program in one operating system, the program is worked in any operating system that is transmitted to the operating system.

b) Portable: The most significant contribution of Java over other languages is its portability.  Java programs can be easily moved from one computer system to another anywhere and any time.  Changes and upgrades in operating systems, processors, system resources will not forces any changes in Java programming.

c) Object oriented: Java is a true object oriented language. Why because without class we can’t run the program.  Without main we can run the program.  Almost everything in Java is an object.  All program code & data reside with objects and classes.  The object model in Java is simple and easy.

d) Robust & Secure: Java is a Robust Language.  It provides many safe guards to ensure reliable code.  It is designed as garbage collected language relieving the programmers, virtually all memory management problems.  Java also incorporates the concept of exception handling, which captures serious errors and eliminates any risk on crashing the system.

            Security becomes an important issue for a language that is used for programming on Internet.  Java systems not only verify all memory access but also ensure that no viruses are communicated with the Applet.

e) Distributed: Java is designed as a distributed language for creating applications on network.  It has the ability to share both data and program.  Java applications can open and remote object on Internet as easily as they can do in local system.

f) Simple & Small: Java is a simple & small language.  Many features of C and C++ that are sources are unreliable code are not part of Java.  For example, Java doesn’t use Pointers, Preprocessors, Header files, goto statements and many others.

g) Multi Threaded: Java was designed to meet the real-world requirement of creating interactive, networked programs.  Java supports multithreaded programming, which allows to handling multi tasks simultaneously.  This means we need not wait for the application to finish one task before beginning another one.

h) Dynamic: Java is a dynamic language.  Java is capable on dynamically linking in new class, libraries, methods and objects.  Java support functions written in other languages such as C and C++.  These functions are known as native methods.  Native methods are linked dynamically at run time.

i) Compile & Interpreted: Usually a Computer language is either compiled or interpreted.  Java combined both these approaches thus making.  Java is a two-stage system.  First Java Compiler translates source code into byte code instruction and therefore in the second stage Java Interpreter generates machine code that can be directly executed by the machine that is running the Java program.

            Interpreter is called JVM (Java Virtual Machine).  Java applications are platform independent.  JVM, JDK are platform dependent.  Interpreter is different for all operating systems like DOS, UNIX etc.,

            The main drawback of C is the program cannot run in any other operating system.  It is advantage of Java.

j) High performance: Java performance is impressing for an interpreted language due to the use of intermediate code.  Java architecture is also design to reduce overheads during runtime.  The incorporation of multithreading enhances, the overall executions, speed of Java programs.