Exception in thread "main" java.lang.NoClassDefFoundError: HelloWorldApp (wrong name: helloworldapp/HelloWorldApp)

C:\>dir
 Volume in drive C has no label.
 Volume Serial Number is 1832-5062

 Directory of C:\

10/05/2008  10:00 AM                 0 AUTOEXEC.BAT
11/17/2008  09:55 PM    <DIR>          Brother
10/05/2008  10:00 AM                 0 CONFIG.SYS
10/05/2008  09:55 AM               211 Copy of boot.ini
10/27/2008  06:49 PM    <DIR>          DELL
10/05/2008  10:09 AM    <DIR>          Documents and Settings
02/05/2009  01:36 PM    <DIR>          Inetpub
11/18/2008  10:56 PM    <DIR>          N360_BACKUP
02/06/2009  11:11 PM    <DIR>          Program Files
02/07/2009  10:49 AM    <DIR>          Temp_MyJava
02/07/2009  09:25 AM    <DIR>          WINDOWS
               3 File(s)            211 bytes
               8 Dir(s)  61,218,283,520 bytes free

C:\>cd temp_java
The system cannot find the path specified.

C:\>cd temp_myjava

C:\Temp_MyJava>dir
 Volume in drive C has no label.
 Volume Serial Number is 1832-5062

 Directory of C:\Temp_MyJava

02/07/2009  10:49 AM    <DIR>          .
02/07/2009  10:49 AM    <DIR>          ..
02/07/2009  10:40 AM               450 HelloWorldApp.class
02/07/2009  09:58 AM               594 HelloWorldApp.java
               2 File(s)          1,044 bytes
               2 Dir(s)  61,218,283,520 bytes free

C:\Temp_MyJava>java HelloWorldApp
Exception in thread "main" java.lang.NoClassDefFoundError: HelloWorldApp (wrong
name: helloworldapp/HelloWorldApp)
        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$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)
        at java.lang.ClassLoader.loadClassInternal(Unknown Source)
Could not find the main class: HelloWorldApp.  Program will exit.

C:\Temp_MyJava>set CLASSPATH=

C:\Temp_MyJava>java HelloWorldApp
Exception in thread "main" java.lang.NoClassDefFoundError: HelloWorldApp (wrong
name: helloworldapp/HelloWorldApp)
        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$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)
        at java.lang.ClassLoader.loadClassInternal(Unknown Source)
Could not find the main class: HelloWorldApp.  Program will exit.

C:\Temp_MyJava>java helloworldapp
Exception in thread "main" java.lang.NoClassDefFoundError: helloworldapp (wrong
name: helloworldapp/HelloWorldApp)
        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$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)
        at java.lang.ClassLoader.loadClassInternal(Unknown Source)
Could not find the main class: helloworldapp.  Program will exit.

C:\Temp_MyJava>

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/*
 * HelloWorldApp.java
 *
 * Created on February 7, 2009
 *
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
 
package helloworldapp;
 
/**
 * The HelloWorldApp class implements an application that
 * simply prints "Hello World!" to standard output.
 */
public class HelloWorldApp {
 
    /** Creates a new instance of HelloWorldApp */
    public HelloWorldApp() {
    }
 
    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
System.out.println("Hello World!"); // Display the string.
    }
 
}