Good work cleaning it up and making it all usable – it’s now looking really nice.

It took me the whole friggin’ weekend, but I finally have something that works pretty well. I had to hack quite a bit, as the whole serialization department of the JDK is not very accessible, but it should work for most cases, and when it doesn’t I fallback on just printing the original exception.

I’m afraid it’s a bit too large too paste, as the main class, SerializableChecker is almost 700 lines. :)

And yes, it is reliable. The initial isEmpty() is because you want to catch the first invocation of the method so you know what the class is of the top-level object you’re serialising. Subsequent calls are all recursive. You’ll note I push and pop exactly once for each field as I iterate over them. Siblings would therefore appear on the same level of the stack. But it’s a stack, not a tree – I’m only recording the bits of the tree that are directly above me on the stack – that’s the whole point.

// Check for circular reference.
if (set.contains(obj)) { return; }

does objectoutputstream really calls write object for the same object twice? I thought this was handled internally by just writing a handle.

Also is this reliable:

if (stack.isEmpty()) { stack.add(“Class ” obj.getClass().getName()); }

How do you know it is really stacked liked that? It doesn’t have to have childs but it could be siblings.