How to throw exception in run() method of Runnable?

Question

Hi, everyone:
I want to know how to throw exception in run() method of interface Runnable. Since there is no throwable exception declared in run() method of interface Runnable in Java API specification.
Thanks in advance,
George

Answer 1

Thanks, jfbriere.
I must add though that if your run() methodis
executed after a call to Thread.start(), then
it is not a good choice to throw anyRuntimeException
from the run() method.
The reason is that the thrown exception won't be
handled appropriately by a try-catch block.Why do you say that "the thrown exception won't be
handled appropriately by a try-catch block"? Can you
explain it in more detail?
regards,
George
Because the other thread runs concurrently with and independently of the parent thread, there's no way you can write a try/catch that will handle the new thread's exception: try {
    myThread.start();
catch (TheExceptionYouWantToThrowFromRun exc) {
    handle it
do the next thing This won't work because the parent thread just continues on after myThread.start(). Start() doesn't throw the exception--run() does. And our parent thread here has lost touch with the child thread--it just moves on to "do the next thing."
Now, you can do some exception handling with ThreadGroup and uncaughtException(), but make sure you understand why the above won't work, in case that was what you were planning to do.