java多线程学习（三）---线程范围内数据共享

来源：互联网发布：jquery.rotate.js 编辑：程序博客网时间：2024/05/29 05:14

初次尝试

public class ThreadScopeShareData {    private static int data = 0;    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();                    System.out.println(Thread.currentThread().getName() + "has put data :" + data);                    new A().get();                    new B().get();                }            }).start();        }    }    static class A{        public void get(){            System.out.println("A from " + Thread.currentThread().getName() + " get data :" + data);        }    }    static class B{        public void get(){            System.out.println("B from " + Thread.currentThread().getName() + " get data :" + data);        }    }}

这里写图片描述
发现取得的数据不正确

修改代码，再次尝试

public class ThreadScopeShareData {    private static int data = 0;    private static Map<Thread,Integer> threadDate = 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();                    System.out.println(Thread.currentThread().getName() + "has put data :" + data);                    threadDate.put(Thread.currentThread(),data);                    new A().get();                    new B().get();                }            }).start();        }    }    static class A{        public void get(){            int data =threadDate.get(Thread.currentThread());            System.out.println("A from " + Thread.currentThread().getName() + " get data :" + data);        }    }    static class B{        public void get(){            int data =threadDate.get(Thread.currentThread());            System.out.println("B from " + Thread.currentThread().getName() + " get data :" + data);        }    }}

这里写图片描述
数据获取正确

也可以使用ThreadLocal来实现

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

这里写图片描述
效果相同

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