import java.util.HashSet;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

public class Main {
   
    private static int Init = 0;
    private static HashSet<Integer> hashSet = new
 
 HashSet();
    private static volatile boolean Finish = true;

    public static void main(String[] args) throws InterruptedException {
        ArrayBlockingQueue<Integer> abq = new ArrayBlockingQueue<>(100);
        ExecutorService exec = Executors.newCachedThreadPool();
        int CONSUMER_COUNT = 20;
        
 
int PRODUCER_COUNT = 2;
        int PRODUCT_THREAD = 100;
        int SUM_PRODUCT = PRODUCT_THREAD*PRODUCER_COUNT;
        for (int i = 0; i < CONSUMER_COUNT; i++) {
            exec.submit(new Runnable() {
                @Override
                public void run() {
                    System.out.println(
 
"Produce Thread Run!");
                    for (; !Thread.interrupted(); ) {
                        try {
                            if (hashSet.size() == SUM_PRODUCT) {
                                exec.shutdownNow();
                                //Finish = false;
                            }
                            Integer val = (Integer) abq.take();
                            hashSet.add(val);
                            System.out.println(val);

                        } catch (InterruptedException e) {
                            //take()發出的中斷訊號被catch後，標誌為將被清楚,要想被for捕捉到，必須重新設定中斷！
                            if (e instanceof  InterruptedException){
                                Thread.currentThread().interrupt();
                            }
                        }
                    }
                }
            });
        }

        for (int i = 0; i < PRODUCER_COUNT; i++) {
            exec.submit(new Runnable() {
                @Override
                public void run() {
                    System.out.println("Produce Thread Run!");
                    for (int i = 0; i < PRODUCT_THREAD; i++) {
                        try {
                            System.out.println("putting..");
                            abq.put(Integer.valueOf(Init++));
                        } catch (InterruptedException e) {
                            e.printStackTrace();
                        }
                    }
                }
            });
        }



        //exec.shutdown();
        //阻塞,等待所有任務執行完畢！
        for (;!exec.awaitTermination(10, TimeUnit.NANOSECONDS););
        System.out.println("hashSet.size():" + hashSet.size());
    }

}

注意:這裡報了一個不應該出現的異常！

如果先submits生產者，並且在消費者執行緒過多的情況下(比如200個)，則會報java.util.concurrent.RejectedExecutionException異常！