Java Stacktrace error Unsupported major.minor version 51.0

Question

Possible Duplicate:
unsupported major .minor version 51.0

I made this script, and it gives me this error:

java.lang.UnsupportedClassVersionError: net/glitching/client : Unsupported major.minor version 51.0
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClassCond(Unknown Source)
    at java.lang.ClassLoader.defineClass(Unknown Source)
    at java.security.SecureClassLoader.defineClass(Unknown Source)
    at java.net.URLClassLoader.defineClass(Unknown Source)
    at java.net.URLClassLoader.access$000(Unknown Source)
    at java.net.URLClassLoader$1.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
Exception in thread "main" 

What does it mean? This is my code...

package net.glitching;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.net.Socket;

public class client {

    static Socket sock = null;

    public static void main(String[] args) {
        while (true) {
            try {
                sock = new Socket("localhost", 4000);
                ObjectInputStream in = new ObjectInputStream(sock.getInputStream());
            } 
            catch (IOException ex) {}
        }
    }

}

Answer 1

Java class files compiled for Java 7 have Major/Minor versions 51/0. If you have a JVM implementation that wasn't prepared for Java 7, it would give you this error indicating "I don't know how to interpret and run this class file."

Try either compiling for an older JVM version, or upgrade your JVM.

Hope this helps!