jHades is a tool that helps troubleshooting classpath problems, see the blog post Demystifying Jar Hell for the main classpath concepts and pitfalls.
- Duplicate classes detection: a command line tool list duplicate classes in a WAR, and allows filtering ‘harmless’ duplicates
- Runtime classpath debugging: a utility class exists to query the classpath at runtime for details on the class loader chain, jars, hidden class files, etc.
- Server startup troubleshooting: jHades works works well in scenarios where the server does not even start