NO.5 线程范围内共享变量的概念与作用(一)

代码：

package thread;

import java.util.Random;

public class ThreadScopeShareData {
    private static int data = 1;
    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 " + Thread.currentThread().getName() + "get data :" + data);
        }
    }
    static class B{
        public void get() {
            System.out.println("B " + Thread.currentThread().getName() + "get data :" + data);
        }
    }
}

输出

Thread-0has put data:-1012275922
Thread-1has put data:1851411786
A Thread-0get data :1851411786
A Thread-1get data :1851411786
B Thread-0get data :1851411786
B Thread-1get data :1851411786

 

此例主要是为了证明，线程范围内共享变量的不同步。