JDecompiler is a very small tool that can decompile the java class file very easily. What's the advantage of JDecompiler. It is very small, and very fast to run. It can use your favorite text editor (e.g EditPlus, UltraEdit) to decompile and view the java class file. Yeah, that's amazing. It can add the original line numbers as the comments in the decompiled file that is very useful for debugging. It is simply to use, you only need to specify your favorite text editor firstly. Then you can double click a class file from the Explorer or a jar(zip) file freely. It will automatically start your favorite text editor to decompile the class file and view the decompiled source code.