Part 1 discussed the need for a new base class for “Imported Java”-agents by extending the lotus.domino.AgentBase class to allow writing, testing and debugging agents from within Eclipse. Suppose we have this new AgentBase implementation – what we really like is for it to revert back to the lotus.domino.AgentBase functionality whenever the agent is run inside Notes/Domino and only use our new AgentBase look-a-like whenever we run inside Eclipse. To do this we need to detect where the code is running.
There are really not that many ways to detect whether the code is running inside Notes/Domino or Eclipse for that matter. My first choice was to look for a System property and found a property called package.restrict.definition.lotus.notes that would allow me to detect whether the code was running inside Notes/Domino. Using this property I could set a flag in the base class that I could query later on:
public abstract class EclipseAgentBase extends AgentBase {
// declarations
private boolean pIsNotes = false;
{
String prop_name = "package.restrict.definition.lotus.notes";
this.pIsNotes = (null != System.getProperty(prop_name));
}
...
...
}
The “strange” construct I use to initialize this pIsNotes member variable is called an initializer. If you would like to learn more about initializers I can recommend an article at Javaworld.com.
There is a problem with using System properties in Notes/Domino since you are only allowed to query a subset of them without having access to restricted operations. Strange but true… This meant I had to scratch that approach since I would really like an approach viable for all agents without requiring restricted access.
I finally settled on using the availability of a class for my detection. Since the Domino Servlet Container classes are only available inside Notes/Domino I could use a class from there. I settled on the DominoSessionContext class from the lotus.domino.servlet-package. The Domino Servlet Container classes are also available in agents since the dservlet.jar is placed in jvm/lib/ext. The detection is now as simple as trying to load the class:
public abstract class EclipseAgentBase extends AgentBase {
// declarations
private boolean pIsNotes = false;
{
try {
Class.forName("lotus.domino.servlet.DominoSessionContext");
this.pIsNotes = true;
} catch (ClassNotFoundException e) {
// ignore - we're not in Notes/Domino
}
}
...
...
}
In this case a java.lang.ClassNotFoundException simply means that the classloader cannot find the class hence we are outside Notes/Domino. Simple but it works.
