Class not found error in Netbeans

Question

I am using Netbeans from many days. But suddenly it started giving me following errors for simple hello programs.

 java.lang.NoClassDefFoundError: newr
 Caused by: java.lang.ClassNotFoundException: newr
at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:276)
at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319)
Exception in thread "main" Java Result: 1 
BUILD SUCCESSFUL (total time: 3 seconds)

here it is

My prog is simple hello program

public class newr {
public static void main(String argv[]){
    System.out.println("hello");
}
}

It happens very very oftentimes with me. I had tried to uninstall and again install it but this doesn't resolve my problem. I also tried to delete .netbeans folder that contain net bean's cache. But i have to delete this .netbeans folder every times it gives me such errors. Is there any way to permanently fix the error? I am tired of deleting the cache and uninstalling netbeans please help me....

Solution

Deleting NetBeans's cache worked for me (version 7.2).

Find the cache folder (In help->about), close NetBeans, navigate to the folder, and delete the index folder. Reopen NetBeans, clean and rebuild, and it should find all the classes this time.

Comments

[Mchl]

You mightalso want to ask this at forums.netbeans.org

[Jean-Philippe Roy]

Might want to post some code of your application, the problem probably isn't your NetBeans installation.

[adesh]

i have included my program in question please go through it

[Matt Handy]

I am not sure but maybe it is related to this problem: http://stackoverflow.com/q/5965798/620338 and has something to do with the lowercase/uppercase class name (class names should begin with an uppercase letter in java).

[adesh]

ya i know class name should beggin with upper case but i was just trying. The error is not case sensitive.

[Abhishek Aggarwal]

see this link may be helpful to you.. stackoverflow.com/questions/3537769/…

[Draque Thompson]

This process worked for me, but is there a way within Netbeans to force this cache clear? I feel like that's a failing on the environment's part if it has to be done manually like this.