线程数组的最佳实践（java）

Question

我在Java线程方面有一些经验，但我想知道…

存储多个线程的最佳实践是什么，我可以在其中单独或成组访问这些线程？

我自己的解决方案是创建一个threadArray类，但是自然地，我希望使用更可靠的本机类。

提前致谢！

编辑

显然，功能对于最佳方法非常重要。好吧，我举一个例子：

我有一个基本上可以同时搜索大量信息的应用程序，因此我正在使用线程。但是，每个线程仅需要执行整个操作的一部分，因此我希望添加其他参数来指定范围。

当一个线程完成它的特定搜索时，它自然就会停止。但是，当线程找到结果时，我希望停止所有线程并检索该结果。

有帮助吗？

Answer 1

我会使用an ExecutorService来将我的线程作为一个池来管理Future，并Threads以某种形式将我添加到池中时得到的s
放入Collection。

通过这种方式，您可以通过执行器将所有线程作为一个单元进行管理，并通过其线程跟踪各个线程Future。

根据您的要求进行编辑

您可以使用的shutdownNow方法ExecutorService来中止所有正在运行的线程。

示例（不是解决问题的方法，但涵盖了使用执行程序的大多数好处）：

// Thread pool for the collectors.
ExecutorService threads = Executors.newFixedThreadPool(MAX_THREADS);
...
// Futures of all collectors running in the pool.
ConcurrentLinkedQueue<Future> collectors = new ConcurrentLinkedQueue<Future>();
...
// Make my Callable.
Callable<Void> c = new FileListCollector(path, recurse, filter);
// Start it up and keep track of it so we can find out when it has finished.
collectors.add(threads.submit(c));
...

// Called when nothing in queue.
private void checkForFinished() {
  // Count the running threads.
  int runningThreads = 0;
  try {
    // Track dead ones to remove.
    List<Future> deadThreads = new LinkedList<Future>();
    // Walk all collectors.
    for (Future f : collectors) {
      // I've seen f being null once. No idea how.
      if (f != null) {
        // If it's not done then it's running.
        if (!f.isDone()) {
          // Count it.
          runningThreads += 1;
        } else {
          // Mark for deletion.
          deadThreads.add(f);
        }
      }
    }
    // Clear dead threads - just to be tidy.
    collectors.removeAll(deadThreads);
  } catch (ConcurrentModificationException cme) {
    // Probably a new thread has been started while I was checking!
    // Therefore almost certainly NOT all finished.
    runningThreads += 1;
  }
  // If no threads are left, we're done.
  if (runningThreads == 0) {
    // Finished! Close everything down.
    close();
  }
}

// Close down the whole system.
public void close() {
  // Use the fileQueue state to indicate closed.
  if (!fileQueue.isClosed()) {
    // Close the queue ... unblocking all collectors (I hope).
    fileQueue.close();
    // Shut them down agressively as this may be called by user prematurely as well as by me.
    threads.shutdownNow();
    // Wait until all is done.
    boolean terminated = false;
    do {
      try {
        // Wait up to 1 second for termination.
        terminated = threads.awaitTermination(1, TimeUnit.SECONDS);
      } catch (InterruptedException ex) {
        // Ignore the interrupt! If I exit here we will probably leak.
      }
    } while (!terminated);
    log("! All done");
  }
}