CODEWITHSUNDEEP
javamultithreading
fortm
fortm

Reputation: 4198

Implement timeout in Java 1.4

I can not use Executor and Future for trapping TimeOutException as it is 1.4 I need to timeout after 30 seconds if method is not complete.

//Caller class
public static void main() {

EJBMethod() // has to timeout after 30 seconds

}

//EJB method in some other class
public void EJBMethod() {

}

An approach that I am thinking is to wrap this method call in a Runnable and set some volatile boolean from run() after method is over. THen , in caller, we can sleep for 30 seconds after calling that method and once woke up, I will check the boolean in caller if it is SET. If not set, then we need to stop that thread.

Upvotes: 4

Views: 862

Answers (1)

Powerslave
Powerslave

Reputation: 1428

In the simplest case, you could just go with a Thread + an arbitrary Runnable.

If you want to make the call blocking from the perspective of the caller, you can create a "service" class that runs a worker thread and uses Thread.join(long) to wait for the operation to complete or abandon it after the specified timeout (Pay special attention to the proper handling of InterruptedException so things don't get messed up).

Thread.isAlive() will tell you whether the Thread finished or not.

Retrieving the result is a separate concern; I guess you can deal with that...

[EDIT]

Quick-and-dirty example (do not use in production as is!):

/**
 * Actually needs some refactoring
 * Also, did not verify for atomicity - should be redesigned
 */
public V theServiceCall(final T param) {
    final MyResultBuffer<V> buffer = new MyResultBuffer<V>();
    Runnable task = new Runnable() {
        public void run() {
            V result = ejb.process(param);
            buffer.putResult(result);
        }
    }
    Thread t = new Thread(task);
    t.setDaemon(true);
    t.start();
    try {
        t.join(TASK_TIMEOUT_MILLIS);
    } catch (InterruptedException e) {
        // Handle it as needed (current thread is probably asked to terminate)
    }
    return (t.isAlive()) ? null : buffer.getResult();
}

NOTE: Instead of Thread.setDaemon() you can implement a shutdown flag in your Runnable as it would be a better solution.

[/EDIT]

Upvotes: 2

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