Java多线程进一步理解之----------线程共享数据

说起线程共享数据有几种方式，

1.使用公共集合类来实现，代码很简单就不多解释：

public class TestThreadShareData {
    private static int data = 0;
    private static Map<Thread,Integer> map = new HashMap<Thread,Integer>();
    public static void main(String[] args) {
        for (int i = 0; i < 2; i++) {
            new Thread(new Runnable() {
                @Override
                public void run() {
                    data = new Random().nextInt();
                    map.put(Thread.currentThread(), data);
                    System.out.println("main" + Thread.currentThread().getName() + "data=" + data);
                    new A().get();
                    new B().get();
                }
            }).start();
        }
    }
    static class A {
        public void get() {
            data = map.get(Thread.currentThread());
            System.out.println("A from main"+Thread.currentThread().getName() + "data = "+data);
        }
    }
    static class B {
        public void get() {
            data = map.get(Thread.currentThread());
            System.out.println("B from main"+Thread.currentThread().getName() + "data = "+data);
        }
    }
}      

2.使用互斥的访问机制

public class doThreadShareData {
    //java.util.concurrent
    public static void main(String[] args) {
        ShareData shareData =new ShareData();
        new Thread(new Runnable() {
            @Override
            public void run() {
                shareData.deccreament();
            }
        }).start();
        new Thread(new Runnable() {
            @Override
            public void run() {
                shareData.increment();
            }
        }).start();
    }

}
class ShareData {
    private int j = 0;
    public synchronized void increment(){
        j++;
    }
    public synchronized void deccreament(){
        j--;
    }
}