I would like to get a reference to all objects in the Java heap, even if I don't immediately have a reference to those objects in my active thread. I don't need non-referenced objects (those "queued" for garbage collection), but would like to get anything that's still in use.
The goal is to serialize and store all the objects to implement a poor-man's persistence of execution state. I realize that the rabbit hole goes deep when it comes to different types of transient state, but simply persisting objects & loaded class definitions would be useful to me.
Is there a way to access the heap in order to make this happen? Am I overlooking a more straightfoward approach?
I'd look into the the instrument package. Instrument the classes you are interested in so the ctor registers the created instance. You might be able to do this via AspectJ should you not want to use the java.lang.instrument or if the objects are created via something you can control (an IoC container or factories) then you can do something a good chunk less magical.