线程通信轮询

浅浅的花香味﹌ 2022-05-14 02:54 166阅读 0赞

### 轮询方式 ###

轮询，可以实现线程通信

package com.bjsxt.base.conn008;
    
    import java.util.ArrayList;
    import java.util.List;
    
    public class ListAdd1 { 
    
        private volatile static List list = new ArrayList();
    
        public void add() {
            list.add("bjsxt");
        }
    
        public int size() {
            return list.size();
        }
    
        public static void main(String[] args) {
    
            final ListAdd1 list1 = new ListAdd1();
    
            Thread t1 = new Thread(new Runnable() {
                @Override
                public void run() {
                    try {
                        for (int i = 0; i < 10; i++) {
                            list1.add();
                            System.out.println("当前线程：" + Thread.currentThread().getName() + "添加了一个元素..");
                            Thread.sleep(500);
                        }
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            }, "t1");
    
            Thread t2 = new Thread(new Runnable() {
                @Override
                public void run() {
                    while (true) {
                        if (list1.size() == 5) {
                            System.out.println("当前线程收到通知：" + Thread.currentThread().getName() + " list size = 5 线程停止..");
                            throw new RuntimeException();
                        }
                    }
                }
            }, "t2");
    
            t1.start();
            t2.start();
        }
    
    }

运行  
![这里写图片描述][70]  
线程t1，向list添加元素  
线程t2，轮询检查list元素个数

当list中有5个元素的时候，执行相应代码

[70]: /images/20220514/1c7cfc3216a6414894b2dbeb3f9f4a81.png