How to add logging to an existing Eclipse plugin to work in 2019-12? - eclipse

Question

I'm trying to fix a problem in an Eclipse plugin at https://github.com/davidmichaelkarr/e4macs . The repo is a fork of the original application, which is now abandonware.
I have a couple problems with this, but I'm going to limit the scope of the question, hopefully making it simpler for someone to provide an answer.
The main problem I'm having with the plugin is that some operations (the operation "split-window-vertically" in particular) simply do nothing when I execute them. This didn't used to be the case. In some recent versions of Eclipse, this was working fine. It stopped working about 2019-09.
What I want to do first is add log statements that show it's at least getting to the handler method. I've concluded that I don't know how to add logging to an Eclipse plugin. The existing code for the plugin doesn't do any logging, so I don't have an example to go by. I've searched the net for documentation on how to do this, but all the articles I've found are either incomplete or just don't work.
I know of at least one handler that IS working properly. I added what I thought was the correct logging code to that handler, and it never appeared in the ".metadata/.log" file, so I assume that that was not the correct way to do logging.
I saw a reference to using "Activator.getDefault()", but that posting didn't say what the FQCN is, and all the completion offerings I found didn't have a "getDefault()" method.
Update:
I added something like the following to two classes:
private ILog logger = Platform.getLog(<ContainingClass>.class);
And then in a method in each of these classes, I used logger.info("message");
I ran this in my debug instance and tested the operations in both classes. The log messages appeared.
I then uninstalled the plugin from the main installation, then built the plugin in my RPC instance, then reinstalled the plugin in the main installation, from the local update site defined by the "...Update" project.
I then tested both operations, and I saw nothing in the log.
I may have solved my logging problem at this point, but I'm still having some sort of problem with deployment. I have a feeling that the process I went through to reinstall the changed plugin is not working.

Answer 1

To get an activator with a getDefault() method you must specify that the plugin contributes to the UI when you create it and that you want an Activator to be created. This should create an activator class extending AbstractUIPlugin and with a getDefault() static method.
In any plugin you can always use:
IStatus status = new Status(....);
ILog log = Platform.getLog(getClass());
log.log(status);
to log a status object.
Status has numerous constructors. A simple one just to log a message is:
new Status(IStatus.INFO, "plugin id", "message");
Platform is org.eclipse.core.runtime.Platform
Status is org.eclipse.core.runtime.Status