Debugging with XStream

A little while back a colleague and I had a problem with some data in a large object graph in our system. There were tens of thousands of objects in the graph so we didn't fancy pointing a graphical debugger at it to find where the problem was residing. Most of the objects didn't define a toString method, so we used XStream to get a representation of the object graph and dump it to the console where we picked through it with command line tools and a XML editor. (We found the problem!) The idiom we used was

new XStream().toXML(objectGraph, System.out);