Java如何在多线程之间共享数据呢?

多线程共享数据的实现思路:
      只需在方法外部定义一个变量
	  然后每个线程方法中都调用此变量

注意事项:
    为了保证线程安全,方法必须加上synchronized关键字

/**
 * 两个线程执行的方法不一样
 */
public class MultiThreadShareData {
    // 库存数字---多线程共享数据
    private int j = 10;

    public static void main(String[] args) {
        MultiThreadShareData multiThreadShareData = new MultiThreadShareData();
        for (int i = 0; i < 2; i++) {
            //增加
            new Thread(multiThreadShareData.new ShareData1()).start();
            //减少
            new Thread(multiThreadShareData.new ShareData2()).start();
        }
    }

    //自增
    private synchronized void Inc() {
        j++;
        System.out.println(Thread.currentThread().getName() + " inc " + j);
    }

    //自减
    private synchronized void Dec() {
        j--;
        System.out.println(Thread.currentThread().getName() + " dec " + j);
    }

    class ShareData1 implements Runnable {
        @Override
        public void run() {
            for (int i = 0; i < 5; i++) {
                Inc();
            }
        }
    }

    class ShareData2 implements Runnable {
        @Override
        public void run() {
            for (int i = 0; i < 5; i++) {
                Dec();
            }
        }
    }
}