future.isDone возвращает false, даже если задача выполнена

У меня сложная ситуация, возвращает ли future.isDone() false false, даже если поток выполнен.

import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.Callable;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;

public class DataAccessor {
    private static ThreadPoolExecutor executor;
    private int timeout = 100000;
    static {
        executor = new ThreadPoolExecutor(10, 10, 1000, TimeUnit.SECONDS, new ArrayBlockingQueue(1000));
    }

    public static void main(String[] args) {
        List requests = new ArrayList();
        for(int i=0; i<20; i++){
            requests.add("request:"+i);
        }
        DataAccessor dataAccessor = new DataAccessor();

        List results = dataAccessor.getDataFromService(requests);
        for(ProcessedResponse response:results){
            System.out.println("response"+response.toString()+"\n");
        }
        executor.shutdown();
    }

    public List getDataFromService(List requests) {
        final CountDownLatch latch = new CountDownLatch(requests.size());
        List submittedJobs = new ArrayList(requests.size());
        for (String request : requests) {
            Future future = executor.submit(new GetAndProcessResponse(request, latch));
            submittedJobs.add(new SubmittedJob(future, request));
        }
        try {
            if (!latch.await(timeout, TimeUnit.MILLISECONDS)) {
                // some of the jobs not done
                System.out.println("some jobs not done");
            }
        } catch (InterruptedException e1) {
            // take care, or cleanup
            for (SubmittedJob job : submittedJobs) {
                job.getFuture().cancel(true);
            }
        }
        List results = new LinkedList();
        for (SubmittedJob job : submittedJobs) {
            try {
                // before doing a get you may check if it is done
                if (!job.getFuture().isDone()) {
                    // cancel job and continue with others
                    job.getFuture().cancel(true);
                    continue;
                }
                ProcessedResponse response = job.getFuture().get();
                results.add(response);
            } catch (ExecutionException cause) {
                // exceptions occurred during execution, in any
            } catch (InterruptedException e) {
                // take care
            }
        }
        return results;
    }

    private class SubmittedJob {
        final String request;
        final Future future;

        public Future getFuture() {
            return future;
        }

        public String getRequest() {
            return request;
        }

        SubmittedJob(final Future job, final String request) {
            this.future = job;
            this.request = request;
        }
    }

    private class ProcessedResponse {
        private final String request;
        private final String response;

        ProcessedResponse(final String request, final String response) {
            this.request = request;
            this.response = response;
        }

        public String getRequest() {
            return request;
        }

        public String getResponse() {
            return response;
        }

        public String toString(){
            return "[request:"+request+","+"response:"+ response+"]";
        }
    }

    private class GetAndProcessResponse implements Callable {
        private final String request;
        private final CountDownLatch countDownLatch;

        GetAndProcessResponse(final String request, final CountDownLatch countDownLatch) {
            this.request = request;
            this.countDownLatch = countDownLatch;
        }

        public ProcessedResponse call() {
            try {
                return getAndProcessResponse(this.request);
            } finally {
                countDownLatch.countDown();
            }
        }

        private ProcessedResponse getAndProcessResponse(final String request) {
            // do the service call
            // ........
            if("request:16".equals(request)){
                throw (new RuntimeException("runtime"));
            }
            return (new ProcessedResponse(request, "response.of." + request));
        }
    }
}

если я вызову future.isDone(), он вернет false, хотя coundownLatch.await() вернет true. Любая идея? Также обратите внимание, что countDownLatch.await появляется сразу же, когда это происходит.

Если вы нашли нечитаемый формат, посмотрите здесь http://tinyurl.com/7j6cvep .

5
задан yadab 9 March 2012 в 19:33
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