java version "1.6.0_24" Java(TM) SE Runtime Environment (build 1.6.0_24-b07) Java Hot

Nixxxter · January 4th, 2012, 02:49 AM

Good Day ,
Please can anyone assist , the problem i am having is the following
when trying to compile my *.java File

Exception in thread "main" java.lang.NoClassDefFoundError: com/sun/tools/javac/M
ain
Caused by: java.lang.ClassNotFoundException: com.sun.tools.javac.Main
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)
Could not find the main class: com.sun.tools.javac.Main. Program will exit.

Any assistance will be greatly appreciated

khadhir · January 4th, 2012, 08:46 AM

check your main class where you declare a main class,
check whether file name matches with class name ,

Nixxxter · January 4th, 2012, 08:53 AM

Hi
Thanks for the reply , I am new to the JAVA language , so i am attempting to write code for the ("Hello World"!) App
I have checked the Hello.Java File name and this corresponds to the declaration

Code:

class Hello

I suspect that there may be something not correct with my Environment variables ??

Nixxxter · January 6th, 2012, 07:41 AM

Hi
I have since uninstalled the version of JRE and JDK i was using
and Installed Java (tm) SE Runtime Enviornment (Build 1.6.0_24-b07)
and JDK 1.6.0_24
to the following Directory C:\Program Files\Java.
In the JAVA Directory two sub folders exist the 1st being : jdk1.6.0_24 & jre6 ,
both have the correct \Bin Sub directories !
I also added the following value:C:\Program Files\Java\jdk1.6.0_24\bin to my Windows XP SP2 system environment variable called PATH

Also after checking the *java File where i declared the main Class

Code:

class Hello

and also checking the *name of the File to make sure that it is the same as the Class which it is, I still get the following error when trying to run the program

Exception in thread "main" java.lang.NoClassDefFoundError: Hello
Caused by: java.lang.ClassNotFoundException: Hello
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)
Could not find the main class: Hello. Program will exit.

mattTyson · January 10th, 2012, 10:34 PM

Can you post the contents of your class file, and also its filename?

The classname and filename don't match, it appears.

Nixxxter · January 11th, 2012, 01:49 AM

Code:

public class Hello
{
  public static void main (String[] args)
  {
  System.out.println("Hello World!");
  }

 }

Question how do i view the contents of the Hello.Class File?
The above code is from the Hello.java file

mattTyson · January 11th, 2012, 12:36 PM

Run it like so:

Code:

java Hello

I think you were running

Code:

java Hello.class //wrong way