Java Web Archive Toolkit
· A collection of libraries to use for reading, writing and validating ARC, WARC and GZip files.
Also includes various helper classes to help with different types of input streams.
Finally there are also classes to help with HTTP, character encoding and other Internet related protocols.
Download JD-GUI to open JAR file and explore Java source code file (.class .java)
Click menu "File → Open File..." or just drag-and-drop the JAR file in the JD-GUI window jwat-1.2.1.jar file.
Once you open a JAR file, all the java classes in the JAR file will be displayed.