Drools, jBPM and Guvnor plugins for Eclipse
· To use these Eclipse plugins in production, use the download site linked on:
http://www.jboss.org/drools/downloads
To use these Eclipse plugins locally during development,
see the pom description of the module org.drools.updatesite.
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 drools-eclipse-7.48.0.Final.jar file.
Once you open a JAR file, all the java classes in the JAR file will be displayed.