Windows platform
================
eg. using JDK 1.5.0_07
1. install jdk
2. add the jdk bin directory into PATH
eg. set PATH=%PATH%;C:\Program Files\Java\jdk1.5.0_07\bin
3. write HelloWorld.java
public class HelloWorld
{
public static void main ( String [] args )
{
System.out.println( "Hello World" );
} // end main
} // end class HelloWorld
4. Change dir to where your .java source is located, compile
javac.exe -classpath . HelloWorld.java
5. execute
java.exe -classpath . HelloWorld