PostgreSQL JDBC driver karaf feature
· An apache karaf feature repository containing a feature that will load and start the PostgreSQL JDBC driver as well as its runtime dependencies
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 postgresql-jdbc-karaf-1.2.0.jar file.
Once you open a JAR file, all the java classes in the JAR file will be displayed.