Context ctx = new InitialContext();
while (ctx != null) { // display one level
     NameClassEnumeration items = ctx.list();
     while (items.hasMoreElements())  {
          NameClassPair item = items.next();
          if (isContext(item.getClassName()))  {
             //  Display context representation
          } else  {
             //  Display object representation
          }
     }
     String target = getNextTarget();
     ctx = (Context)ctx.lookup(target);
     ...
     }
}