SOT: Watch those java jars (follow the bouncing server)

Well this is a new one for me. Earlier I was testing a java jar I had read about on an older blog entry. But when I ran the test code the sample output I was expecting never appeared. Just a lot of whitespace and the standard debug output. At first I thought maybe I had used the wrong parameters or that the jar had changed. But there was no error anywhere. Not even in the logs. At least as far as I could tell.

Finally, I checked the windows services panel and noticed the ColdFusion 8 service said "Starting ...". After it started, I ran the script again and re-checked the services panel. Sure enough the status of the ColdFusion service was back to "Starting..". What the heck ...?

After scratching my head for a few minutes, I finally checked the jar source. (Thank goodness for open source!). That is when I noticed System.exit(..) was called in several places, for some reason. Perhaps because it has a gui component as well. So instead of throwing an exception, the code shut down the jvm ... and of course the ColdFusion Server! Shutting down might be okay for desktop usage, but it is usually an undesirable behavior on a server.

Today's note to self: Always check the java source of new jars. Especially those with gui components. Bad System.exit(..)!