I\'d like to add a custom warning message (i.e. add an entry to the Warnings section of the Problems tab) for .java
files in Eclipse.
While I\'ve found
I think that a builder might be appropriate for what you want to do. There's a template in the new plugin wizard that creates everything you need for a builder (ex. business logic). Since the builder runs every time the file is modified, you can clear the old warning (code generated for you) and add a new warning (code generated for you) if applicable. This also applies when the file is first created.
You could even look through the code and find hard-coded strings and flag them with warnings if you want.
As for the comments marking translation keys in the code today, those are there to guide NLS tools (you probably already knew that). The idea was to write the code first and then go back later and translate. If a change is made to the code later, the tools can run again and only act on new strings added by the delta.