Java AWT Robot and Windows Remote Desktop

Adrian Sutton

Problem

If you’re attempting to use the Java AWT Robot to help automate tests, you may find it convenient to log in via remote desktop to watch the tests execute and verify they work well. You may also find that they work fine while you’re watching them but then inexplicably start failing whenever you aren’t. Basically your test is an angel from Dr Who.

What’s most likely happening is that when you disconnect from the remote desktop session, the console on the Windows box is left in a locked state and you need to enter the user password before you can resume interacting with programs on the main display. Since the AWT Robot is doing a very effective job of acting like a user, it also can’t interact with the programs you’re intending and instead is interacting, probably quite ineffectively, with the login dialog box.

Solution

It may be possible to get the AWT Robot to actually login before continuing, but then your tests would break when you were watching and it complicates the tests. Instead, you can take two approaches:

  1. Stop using remote desktop and switch to VNC which doesn’t lock the screen when you disconnect.
  2. Rather than disconnecting from remote desktop, transfer the session back to the console. Use Start->Run or a DOS prompt and run: 
    tscon.exe 0 /dest:consol

Or of course just get up and walk over to the remote machine and watch the tests on the console directly, but that’s not always a viable option.