How to remove class file in .jar file and change it with my own implementation [duplicate]
There are multiple ways to do this:
Try to use winrar. You can open your jar in it, explore the directory containing the class file. You can delete and add class files.
If you don't want to use winrar then do like this:
Extract the jar using this command
jar -xvf yourjar.jar
It will explode the jar. Delete the old class file and add your updated class file
Recreate the jar using the following command
jar -cvf yourjar.jar directoryofexploderjar/
Extend class and rewrite method removing bug
Use JDEC to decompile and replace class ( http://jdec.sourceforge.net/ )
Write your own class in the same package as the original one, make sure your classes are before the 3-rd party jar on the java classpath. This way you will override the original version, class loader will load your class.