java并发计数器问题

package com.tongbanjie.trade.test.base;  

  

import java.util.concurrent.TimeUnit;  

import java.util.concurrent.atomic.AtomicInteger;  

  

/** 

 * 测试并发累加 

 * @author huangqun 

 * 

 */  

public class TestConcurrentPlusPlus {  

  

    public static int count = 0;  

      

    public volatile static int volatileCount = 0;  

      

    public static int synchronizedCount = 0;  

      

    public static AtomicInteger atomicCount = new AtomicInteger(0);  

      

    public volatile static AtomicInteger volatileAtomicCount = new AtomicInteger(0);  

      

    public static void main(String[] args) {  

          

        final Object lock = new Object();  

          

        for (int i = 0; i < 50000; i++) {  

            new Thread(new Runnable() {  

                  

                @Override  

                public void run() {  

                    count++;  

                    volatileCount++;  

                      

                    synchronized (lock) {  

                        synchronizedCount++;  

                    }  

                      

                    atomicCount.incrementAndGet();  

                    volatileAtomicCount.incrementAndGet();  

                }  

            }).start();  

        }  

          

        // 休息5秒, 保证线程中的计算完成  

        try {  

            TimeUnit.SECONDS.sleep(5);  

        } catch (InterruptedException e) {  

            e.printStackTrace();  

        }  

          

        System.out.println("线程并发执行对计数器累计5000次，看并发结果！");  

        System.out.println("count=" + count);  

        System.out.println("volatileCount=" + volatileCount);  

        System.out.println("synchronizedCount=" + synchronizedCount);  

        System.out.println("atomicCount=" + atomicCount.get());  

        System.out.println("volatileAtomicCount=" + volatileAtomicCount.get());  

          

    }  

}