Parent for the Google API Client Library for Java
· The Google APIs Client Library for Java is a Java client library
for accessing any HTTP-based API on the web
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 google-api-client-parent-2.2.0.jar file.
Once you open a JAR file, all the java classes in the JAR file will be displayed.