A simple, text based Java Bytecode Editor. It uses ObjectWeb ASM (http://asm.ow2.org/) and the RSyntaxTextArea from https://github.com/bobbylight/RSyntaxTextArea
To open up a file, drag it onto the left side. To save a class, press CTRL + S on the right side, to save the jar file, press on the left side. With F5 you can reload either the file or only the class.
To search/replace in a file, press CTRL + F.
To open a class, press CTRL + T.
To change settings like auto-computation of stack frames and max locals/stack press CTRL + O.
To (un-)escape unicode characters, press CTRL + U.
To rename a field/method with attention to references in the selected line, press CTRL + R.
To quickly compile some java code, press CTRL + E.
To switch between themes, press CTRL + B.