A number of general purpose libraries for Java. Dependencies are kept minimal but Spring framework 3.x
is considered a base requirement for most libaries.
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 common-projects-1.1.jar file.
Once you open a JAR file, all the java classes in the JAR file will be displayed.