getting the name of a jar file from inside the jar

[Jason Kretzer]

I have a jar. This jar has code in it similar to this:

JarFile studyJar = new JarFile(studyID+"."+studyVersion+".jar");
Enumeration enum = studyJar.entries();  

studyJar is a JarFile representation of the jar this code is executing in. I get studyID and studyVersion from a text file located inside the jar.
I need to add the functionality where the jar can be renamed by end users.
Is it possible for code inside of a jar to get the name of the jar it resides in? I need its name to instantiate the JarFile above.
Thanks,
[ March 28, 2002: Message edited by: Jason Kretzer ]

[Jason Kretzer]

If you do not believe it to be possible at least tell me that. I don't want to waste my time looking for something that is not there.
Thanks,

[David Weitzman]

This is one solution. It's painful. I hope there is a better way, but I don't know one.
Grrr. HTML is not enabled.

import java.net.URL;
public class Test {
    public static void main(String[] args) {
        Class cl = Test.class;
        
        URL url = cl.getResource("/" + cl.getName().replace('.', '/') + ".class");
        
        System.out.println(url);
        
        // in the form file:/to/where/the/jar/is.jar!/Test.class
        String path = url.getPath();
        System.out.println("Path: " + path);
        
        // cut off at the !
        String jar = path.substring(0, path.indexOf('!'));
        
        System.out.println("Jar file url: " + jar);
    }
        
}

[ March 28, 2002: Message edited by: David Weitzman ]

[Ivor Horton]

Jason,
I haven't tried it but if you have the JarFile object, the getName() method that is inherited from java.util.ZipFile might help.

[Jason Kretzer]

No, I need the name of the jar to instantiate the JarFile object to begin with.
Thanks though,