当CountDownLatch的计数为零时，丢失的HTTP请求在哪里

Question

我正在测试一个多线程代码，该代码使用CloseableHttpAsyncClient客户端发送一组http请求(请参阅下面的代码片段(。

我正在获得以下输出：

Failed ->java.io.IOException: Connection reset by peer-null
Failed ->org.apache.http.ConnectionClosedException: Connection closed-null
Thread: 0-Time: 2955ms-Completed: 1000-Failed: 0-Cancelled: 0- Countdown: 0
Thread: 1-Time: 2855ms-Completed: 999-Failed: 0-Cancelled: 0-Countdown: 0
Thread: 2-Time: 2741ms-Completed: 999-Failed: 1-Cancelled: 0-Countdown: 0
Thread: 3-Time: 2678ms-Completed: 999-Failed: 1-Cancelled: 0-Countdown: 0
Thread: 4-Time: 2654ms-Completed: 1000-Failed: 0-Cancelled: 0-Countdown: 0

因此，其中两个线程正确执行了所有1000个请求，另外两个线程出现了连接错误，这些错误被正确捕获，其中一个线程(编号1(完成了999个请求，没有收到任何失败或取消的通知。

我的问题是：

1. 失败的方法中有没有任何方法可以理解哪一个是失败的请求，这样我就可以进行后处理来重新发送那些失败的请求？

2. 为什么在没有失败、取消或异常的情况下，倒计时的次数会达到0，而不是所有的请求都完成了？

   class AsynchThread extends Thread{      
   CloseableHttpAsyncClient httpclient;
   int n;
   int ncompleted =0;
   int nfailed =0;
   int ncancelled =0;
   long time;
   CountDownLatch latch;
   public AsynchThread(CloseableHttpAsyncClient httpclient, int n) throws IOReactorException {
   this.jobs = jobs;
   this.httpclient = httpclient;
   this.n = n;
   }
   public void process() throws InterruptedException, IOException {
   latch = new CountDownLatch(n);
   long starttime = System.currentTimeMillis();
   for (int v=0;v<n; v++) {
   HttpPost httppost = ...
   httpclient.execute(httppost, new FutureCallback<HttpResponse>() {
   public void completed(final HttpResponse response) {
   latch.countDown();
   ncompleted += 1;
   }
   public void failed(final Exception ex) {
   latch.countDown();
   nfailed += 1;
   System.out.println("Failed ->" + ex);
   }
   public void cancelled() {
   latch.countDown();
   ncancelled += 1;
   System.out.println("Cancelled ->" + ex);
   }
   });
   }
   latch.await();
   time = System.currentTimeMillis()-starttime;
   }
   public void run() {
   try {
   process();
   }catch(Exception e) {
   System.out.println(e.getStackTrace());
   }
   }
   }
   public static void main(final String[] args) throws Exception {
   CloseableHttpAsyncClient httpclient = ...
   int n = 5;
   int nprocthread = 1000;
   AsynchThread[] threads = new AsynchThread[n];
   for (int i=0; i<n; i++) {
   threads[i] = acall.createThread(httpclient, nprocthread);
   threads[i].run();
   }
   for(int i = 0; i < threads.length; i++)
   threads[i].join();
   for(int i = 0; i < threads.length; i++) {
   System.out.println("Thread: " + i + "-Time: " + threads[i].time + "ms-Completed: " + 
   threads[i].ncompleted + "-Failed: " + threads[i].nfailed + "-Cancelled: " + 
   threads[i].ncancelled + "-Countdown: " + threads[i].latch.getCount());
   }
   }
   

非常感谢。

Answer 1

添加标题"连接：关闭"时，所有问题都得到了解决