/**
 * @(#)test.java
 * test application
 */
import java.io.*;

public class test
{
   
    public static void main(String[] args)
    {
  String version = System.getProperty(”java.version”);
        System.out.println(”JDK version installed is “+ version);

    }

}

On my system I had

JDK version installed is 1.6.0_12

/**
 * @(#)test.java
 * test application
 */
import java.io.*;

public class test
{
   
    public static void main(String[] args)
    {
  String name = System.getProperty(”user.name”);
        System.out.println(name);
    }

}