Java AtomicInteger 类

public class TestThread {

   static class Counter {
      private int c = 0;

      public void increment() {
         c++;
      }

      public int value() {
         return c;
      }
   }

   public static void main(final String[] arguments) throws InterruptedException {
      final Counter counter = new Counter();

      //1000 threads
      for(int i = 0; i < 1000 ; i++) {

         new Thread(new Runnable() {

            public void run() {
               counter.increment();
            }
         }).start();
      }  
      Thread.sleep(6000);
      System.out.println("Final number (should be 1000): " + counter.value());
   }  
}