是否可以在Java中的指定时间内停止函数的执行？

Question

I want to know how to stop a specified function's execution within a specified time in java.

For example: I may call a function called print_data(). If it takes more time to execute, I will have to stop that function's execution.

Is it possible to stop the execution like this?

Thanks in advance

Answer 1

You could add some checks to your function: save the timestamp when function started working and then periodically checking that inside the function, throwing an exception if function takes too long.

This is the cleanest way to accomplish such task in Java.

Answer 2

There is no safe way to stop a thread executing, unless it is being cooperative; eg it regularly checks the 'interrupted' flag.

@BobbyShaftoe suggests this in a comment:

You could execute this function in a separate thread and then abort the thread after some period of time.

This is misleading and dangerous advice. The only way to "abort" a thread is to use the deprecated Thread.stop() method. If you look at the javadoc for that method you will see that it is a fundamentally dangerous method that is liable to have undesirable and unpredictable side-effects.

It should also be noted that @tonio's solution doesn't stop the function's execution. It simply stops waiting for the function's execution to finish. The function could continue executing indefinitely, chewing up resources to no good effect.

Answer 3

You can use the TimeUnit enum from java.util.concurrent , in particular the timedJoin method.

You specify a time to wait, and a thread. timedJoin will let your thread execute until termination, or stop if the processing takes more time than the timeout allowed. You can use an anonymous class to wrap your method in a Thread object easily.

This can be as easy as:

SECONDS.timedJoin(
    new Thread() {
      public void run() {
        print_data();
      }
    },
    10);    

for a 10 seconds timeout.