Need Help on :: Programatically Creating Jar file From Existing Jar file

[vijay kurhade]

I am trying to create dummy jar file based on existing jar file; using java.util.Jar package classes like JarFile, JarOutputStream, Manifest class objects.


What I am tryig to do is

I have A.jar file
read A.jar; JarFile
get its manifest object with JarFile.getManifest()

manifest.put("READER", "MyName");

If i specify this manifest in
JarOutputStream(outputstream, manifest);

Get ZipException -> Duplicate META-INF\META-INF.MF entry



What is the best way to achieve creating copy of one jar to another with slight change to manifest file.


Help is Appreciated

[Campbell Ritchie]

Easiest done from the command line, I would think. There should be something in the Java Tutorials; there is a section about modifying the manifest file.

[Bert Bates]

intermediate level