hello world fails !

/*
   * To change this template, choose Tools | Templates
   * and open the template in the editor.
   */
  package javaapplicationtest;
  //import java.io.*;
  /**
   *
   * @author Administrator
   */
  public class JavaApplicationTest {
  
      /**
       * @param args the command line arguments
       */
      public static void main(String[] args) {
          // TODO code application logic here
          System.out.println("Hello World!");
      }
  }

run using the java command :

Exception in thread "main" java.lang.NoClassDefFoundError: JavaApplicationTest (wrong name: javaapplicationtest/JavaAppl
  icationTest)
          at java.lang.ClassLoader.defineClass1(Native Method)
          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$100(Unknown Source)
          at java.net.URLClassLoader$1.run(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)
          at sun.launcher.LauncherHelper.checkAndLoadMain(Unknown Source)

in netbeans which can normally output : Hello World!

JDK path : E: \ Java \ jdk1.7.0_40
JRE path : D: \ Java \ jre7
OS partition : D:
------ Solution ------------------------------- -------------
eclipse in the build environment set up what you