问访问共享资源的线程数

EN

public class YourResource {
   private static final int MAX_CONCURRENT_THREADS = 4;

   private Semaphore semaphore = new Semaphore(MAX_CONCURRENT_THREADS ); 

   public void doSomethingWithYourResource() {
      semaphore.acquire();
      try {
         // Code accessed by 4 concurrent threads, tops
      } finally {
         semaphore.release();
      }
   }
}

ExecutorService executor = Executors.newFixedThreadPool(4);
        for (int i = 0; i < 4; i++) {
             Task task = new Task(someParam, someParam);
            executor.execute(task);
          }
        executor.shutdown();