After downloading eclipse plugin for Java Decompiler from http://java-decompiler.github.io/ follow below steps
- Download JD-Eclipse ZIP file,
- Launch Eclipse,
- Click on "Help > Install New Software...",
- Drag and drop ZIP file on dialog windows,
- Check "Java Decompiler Eclipse Plug-in",
- Click on "Next" and "Finish" buttons,
- A warning dialog windows appear because "org.jd.ide.eclipse.plugin_x.y.z.jar" is not signed. Click on "Install anyway" button.
- Click on "Windows > Preferences "
- Search for "File Association"
- For "*.class" & "*.class without source" select Associate editor as "JD class file viewer". 👍