从主线程休眠是抛出InterruptedException

Question

I have the main thread of execution which spawns new threads. In the main thread of execution in main() I am calling Thread.sleep() . When do I get an Unhandled exception type InterruptedException ?.

I am unsure of why am I getting this. I thought this was because I needed a reference to the main thread so I went ahead and made a reference to it via Thread.currentThread() .

Is this not the way to have the thread sleep? What I need to do is have the main thread wait/sleep/delay till it does it required work again.

Answer 1

What you see is a compilation error, due to the fact that you didn't handle the checked exception ( InterruptedException in this case) properly. Handling means doing one of the following:

1) Declaring the method as throws InterruptedException , thus requiring the caller to handle the exception

2) Catching it with a try{..}catch(..){..} block. For example:

try {
    Thread.sleep(1500);
} catch(InterruptedException e) {
    System.out.println("got interrupted!");
}

InterruptedException is used to indicate that the current thread has been interrupted by an external thread while it was performing some blocking operation (eg interruptible IO, wait, sleep)

Answer 2

At the line where you're definition of main starts, just include throws Exception . I too was facing similar problem, and this helped. After this inclusion, you need not include the Thread.sleep(xx); inside a try-catch statement

Answer 3

Thread.sleep(t);

This is how you can make your thread wait. where t is in milliseconds. It is working fine in my main method, so to find out your problem it would be better if you can provide your code here.