How to add a class to a .jar library?

I need to add a class to a .jar library but I can't figure out how to do it. I have a library named netty-3.1.5.GA.jar but for some reason its missing a c开发者_如何转开发lass I need (HttpTunnelClientChannelFactory.java).

I have found that class on a repository but not as part of the library. So how can I 'inject' it? The class I need to add is using other classes that exist in the library.

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You don't need to add it to the jar, you need to add it to the classpath of whatever it is you're running.

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You can use the jar tool to update the jar file: you will need to manually create the appropriate package directory though. Try this:

jar uf netty-3.1.5.GA.jar HttpTunnelClientChannelFactory.class

will add it to the root package. If you need it to be set up in a package directory you should create the directory structure and then add the file with a path.

EDIT: that should be .class, not .java.