Why is spawning threads in Java EE container discouraged?

Question

One of the first things I\'ve learned about Java EE development is that I shouldn\'t spawn my own threads inside a Java EE container. But when I come to think about it, I do

Answer 1

There is no real reason not to do so. I used Quarz with Spring in a webapp without problems. Also the concurrency framework java.util.concurrent may be used. If you implement your own thread handling, set the theads to deamon or use a own deamon thread group for them so the container may unload your webapp any time.

But be careful, the bean scopes session and request do not work in threads spawned! Also other code beased on ThreadLocal does not work out of the box, you need to transfer the values to the spawned threads by yourself.