Forcing TaskRejectedException in Spring

Suppose (for testing purposes) you want to force a TaskRejectedException when using Spring Integration channels. All you have to do is

• send a reasonable number of objects to the channel (let's say a minimum of 5)
• configure your queue capacity to .. 0
• and (important) set the thread-pool size to (as low as you can) 1

I'm using a task executor in this example:

id="someExecutor" keep-alive="120" pool-size="1" queue-capacity="0"

Good luck