I have a Jar file, which contains other nested Jars. When I invoke the new JarFile() constructor on this file, I get an exception which says:
java.util.zip.ZipException: error in opening zip file
When I manually unzip the contents of this Jar file and zip it up again, it works fine.
I only see this exception on WebSphere 6.1.0.7 and higher versions. The same thing works fine on tomcat and WebLogic.
When I use JarInputStream instead of JarFile, I am able to read the contents of the Jar file without any exceptions.