Examples of java.util.concurrent.BlockingQueue.drainTo()

java.util.concurrent.BlockingQueue.drainTo()

Removes all available elements from this queue and adds them to the given collection. This operation may be more efficient than repeatedly polling this queue. A failure encountered while attempting to add elements to collection {@code c} may result in elements being in neither,either or both collections when the associated exception is thrown. Attempts to drain a queue to itself result in {@code IllegalArgumentException}. Further, the behavior of this operation is undefined if the specified collection is modified while the operation is in progress. @param c the collection to transfer elements into @return the number of elements transferred @throws UnsupportedOperationException if addition of elementsis not supported by the specified collection @throws ClassCastException if the class of an element of this queueprevents it from being added to the specified collection @throws NullPointerException if the specified collection is null @throws IllegalArgumentException if the specified collection is thisqueue, or some property of an element of this queue prevents it from being added to the specified collection

        BlockingQueue q = new SharedConcurrentBlockingObjectQueue<Integer>(SIZE * 2, Integer.class);
        for (int i = 0; i < SIZE + 2; ++i) {
            for (int j = 0; j < SIZE; j++)
                assertTrue(q.offer(new Integer(j)));
            ArrayList l = new ArrayList();
            q.drainTo(l, i);
            int k = (i < SIZE) ? i : SIZE;
            assertEquals(k, l.size());
            assertEquals(SIZE - k, q.size());
            for (int j = 0; j < k; ++j)
                assertEquals(l.get(j), new Integer(j));


    BlockingQueue newQueue = QueuesHolder.getQueue(queueName);
    task.start();


    List list = new ArrayList();
    newQueue.drainTo(list);


    assertEquals(2, list.size());
    assertEquals(date1, list.get(0));


    //判断存在持久化文件

All source code are property of their respective owners. Java is a trademark of Sun Microsystems, Inc and owned by ORACLE Inc. Contact coftware#gmail.com.