title: Does the Java API have a data structure to represent hierarchy
body: <p>I've got two classes; one interprets commands, and sends these commands to another class which executes them.  I then want the class which executes the commands to be able to send the results of this execution back to the interpreter class.  The problem is that these results are hierarchal in nature.</p>
  
  <p>Right now the only thing I know of in the Java API that will let me do this is the DOM.  I really don't want to futz around with the DOM, creating a new document and then sending a piece of it back to the other class; it just seems like a BIG MESS.  Is there anything else I can use?</p>