Run time error

[Varshini Priya]

Hi

Im trying to execute the below code
[Code]

package cert;
public class Sludge
{
public void testIt()
{
System.out.println("sludge");
}
}

[\code]



I have stored the above code in this location D:\Java\Sludge.java and the below one. I have saved it in D:\java1\Goo.java
[code]
package book;
import cert.*;
class Goo
{
public static void main(String [] args)
{
Sludge o = new Sludge();
o.testIt();
}
}
[\code]

I was able to compile the code fine. I did set the below classpath. But was still getting errors.

Output

D:\java1>set classpath=%classpath%;D:\Java; D:\java1;

D:\java1>java Goo
Exception in thread "main" java.lang.NoClassDefFoundError: Goo (wrong name: book
/Goo)
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:620)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:12
4)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:260)
at java.net.URLClassLoader.access$100(URLClassLoader.java:56)
at java.net.URLClassLoader$1.run(URLClassLoader.java:195)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:268)
at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319)

D:\java1>

Im not sure why Im getting the above error. Please assist. Many Thanks

[Ulf Dittmer]

The directory hierarchy must correspond to the package hierarchy. Since those classes are in packages "cert" and "book", respectively, they need to be in subdirectories of the same name.

[Varshini Priya]

Hi Ulf,

Im sorry. But I dint get You. "they need to be in subdirectories of the same name. " - Im not sure what this actually,means. Please Assist

[Maneesh Godbole]

What Ulf meant was that the class Sludge.java should be saved as D:\Java\cert\Sludge.java and Goo.java should be saved as D:\java1\book\Goo.java

[Varshini Priya]

Hi

I did put the respective classes in the subdirectories and tried to run the program. getting the same error as above. Im able to compile it fine. But not able to run it.

Output

D:\java1\book>javac Goo.java

D:\java1\book>set classpath=%classpath%;D:\Java\cert;D:\java1\book;

D:\java1\book>java Goo
Exception in thread "main" java.lang.NoClassDefFoundError: Goo (wrong name: book
/Goo)
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:620)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:12
4)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:260)
at java.net.URLClassLoader.access$100(URLClassLoader.java:56)
at java.net.URLClassLoader$1.run(URLClassLoader.java:195)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:268)
at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319)

[Henry Wong]

Try....

D:> cd \Java
D:\Java> javac cert\Sludge.java

D:\Java> cd \java1
D:\java1>javac book\Goo.java

D:\java1>java book.Goo

Henry

[Campbell Ritchie]

Have both Sludge and Goo compiled correctly?

If so, navigate to the folder which contains the cert and book folders. I think that means D:\Java

You need to call the class with the main method by its fully-qualified name: java cert.Goo

[Campbell Ritchie]

By the way: please use the CODE button and maintain indentation. Don't write the code tags by hand; the button is quicker and less prone to spellling errors.

[Henry Wong]

set classpath=%classpath%;D:\Java\cert;D:\java1\book;

And the classpath should be the top of the packages... so this line should be...

set classpath=%classpath%;D:\Java;D:\java1;

Henry

[Henry Wong]

Campbell Ritchie wrote:By the way: please use the CODE button and maintain indentation. Don't write the code tags by hand; the button is quicker and less prone to spellling errors.

BTW, I thought I would be nice and fix the code tags.... But it would not matter. There is no formatting to the code that has been included.

Henry

[Varshini Priya]

Thanks a lot Henry. It did work

[Campbell Ritchie]

Henry Wong wrote:I thought I would be nice and fix the code tags.... But it would not matter.

I tried too; if it works I usually say "see how much better it looks."