Java线程..导致线程在设置的时间后终止

Question

I have written some code that submits a callable to an executor, storing the future in a map against an id. In the call method I wait for a flag to be set before proceeding. Basically I need to wait for an external operation to return to me and say we are done - here is the data and now you can continue... I dont think what I have is correct:

public class MyClass implements Callable<Boolean> {

    ---
    ---
    private boolean done = false;

    @override
    public Boolean call() {

        --  wait for flag to be set...
        //continue....
    }

}

--main code--

//create the above class..

//submit it...

//get the future store in map...

//-- wait for response from external application...

///tie it up with an id

//set the attribute so the callable can continue and complete..

Questions:

1. The above will not work as I am returned a Future and not the object. I was thinking of maybe creating a new interface which inherits from the callable class - does that make sense?

2. I need the thread to wait and then die if no response is received. Is it possible to set that on a thread at all?

Answer 1

You can schedule a task which will cancel the waiting task. When the waiting task finishes it can cancel the scheduled task. (which ever finished first will cancel the other)

This assumes you have a task which is interruptible in the first place.

Answer 2

there is a wait(long timeout) function available.. heres some documentation on it

http://docs.oracle.com/javase/1.5.0/docs/api/java/lang/Object.html

with this wait(long timeout) function, the thread will wait until it gets a notify() (or notifyAll()) OR until the timout expires.

any of the following will break the wait();

1. notify();
2. notifyAll();
3. timout gets reached

Answer 3

Use the Future#get(long, TimeUnit) .

This will wait for some time for an answer, and throw a TimeoutException if there is no return value in the given period. Then just catch the exception and let the thread finish grafefully.