Java多线程进一步理解之----------线程共享数据

Bertha 。 2022-05-17 04:22 264阅读 0赞

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--;
        }
    }