java - 并发创建动态线程数

Question

每次我都必须创建可变数量的线程。 为此，我创建了一个线程数组并创建了多个线程。

但是，我不明白如何启动这 n 个线程，这些线程的行为类似于多线程概念。 我希望它们并行运行。

如果在此场景中做什么，请指导。

Answer 1

But, I don't understand how to start these n number of threads behaving like multi threading concept. I want them to run in parallel.

当然可以使用循环创建线程数组:

 Thread[] threads = new Thread[NUM_JOBS_TO_CREATE];
 for (int i = 0; i < threads.length; i++) {
     threads[i] = new Thread(new Runnable() {
         public void run() {
             // some code to run in parallel
             // this could also be another class that implements Runnable
         }
     });
     threads[i].start();
 }

这将导致线程在后台并行运行。然后您可以稍后加入他们，等待他们全部完成后再继续。

// wait for the threads running in the background to finish
for (Thread thread : threads) {
    thread.join();
}

但与其自己管理线程，我建议使用内置的 Java Executors .他们为您做所有这一切，更易于管理。此方法的好处之一是它将任务 与运行它们的线程 分开。例如，您可以启动 10 个线程来并行运行 1000 个和 1000 个任务。

下面是一些示例 ExecutorService 代码:

 // create a pool of threads, 10 max jobs will execute in parallel
 ExecutorService threadPool = Executors.newFixedThreadPool(10);
 // submit jobs to be executing by the pool
 for (int i = 0; i < NUM_JOBS_TO_CREATE; i++) {
    threadPool.submit(new Runnable() {
         public void run() {
             // some code to run in parallel
             // this could also be another class that implements Runnable
         }
     });
 }
 // once you've submitted your last job to the service it should be shut down
 threadPool.shutdown();
 // wait for the threads to finish if necessary
 threadPool.awaitTermination(Long.MAX_VALUE, TimeUnit.MILLISECONDS);

有关详细信息，请参阅 Java tutorial on the thread executors .