Is there are way to patch jar files?

Question

Suppose I sent a large jar or war file to someone. Could I later just change one small section and send that to him? Suppose I just changed one class file. I recompiled t

Answer 1

The person receiving the class file could simply add that file to the jar as long as they know which directory to put it in. Be weary of signed jars, as noted in the comments.

jar uf foo.jar foo.class

http://docs.oracle.com/javase/7/docs/technotes/tools/solaris/jar.html