Thread Interruption in Java

This week a question came up at work about the best way to handle an InterruptedException thrown from Thread.sleep(...). Often times, developers will simply catch this exception, and then just print a stack trace, or leave the block completely empty. However, this is not good practice, since you are essentially ignoring the fact that your app has been interrupted:

For example, say you have a thread which processes a given number of records, with a configurable sleep in between each record to allow you to throttle the speed. If not handled properly, the thread will never exit gracefully. For example:

Note that simply calling Thread.currentThread.interrupt() will not kill the running thread. In this case, the thread will continue to run, interrupting itself over and over again. A better way to handle the InterruptedException is to gracefully discontinue processing records, for example:

In this example, the private sleep method properly throws the InterruptedException up the stack to a piece of code which knows how to handle it properly.

To run an example of the non-interruptable runnable and the interruptable runnable, you can clone the project from GitHub Here.