java 線程池等待所有線程返回結果

 //開始多線程任務
    public Map<String, String> start(List<PddAccount> list) throws InterruptedException {
        CountDownLatch count = new CountDownLatch(list.size());
        Map<String, String> tasks = tasks(list, count);
        return tasks;
    }

    //執行多線程任務
    public Map<String,String> tasks(List<PddAccount> list, CountDownLatch count) throws InterruptedException {
        Map<String,String> map=new HashMap<>();
        ExecutorService pool = Executors.newFixedThreadPool(30);
        for (int i = 0; i < list.size(); i++) {
            PddAccount str = list.get(i);
            Runnable run = new Runnable() {
                public void run() {
                    try {
                       //需要多線程執行的代理
                        System.out.println(Thread.currentThread().getName()+"___"+str.getAccount());
                        map.put(Thread.currentThread().getName(),"true");//模擬返回結果
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                    count.countDown();
                }
            };
            pool.submit(run);
        }
        pool.shutdown();
        //所有線程提交完,等待所有線程結束
        count.await();//阻塞在這裏,等到所有線程返回結果
        return map;
    }