Jnrpe Package
· JNRPE is a Nagios addon that makes simple the implementation of Nagios plugins using the Java Language.
It is fully compatible with check_nrpe and can be used to execute both old native Nagios plugins and the new Java Nagios Plugins.
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 jnrpe-parent-2.0.5.jar file.
Once you open a JAR file, all the java classes in the JAR file will be displayed.