关于线程轮流打印0-99

使用Reentrantlock实现

package com.wang;


import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.ReentrantLock;

public class Solution {
    public static int n=0;
    public static void main(String[] args) {
        ReentrantLock lock=new ReentrantLock();
        Condition conditionodd=lock.newCondition();
        Condition conditioneven=lock.newCondition();
        Thread threadeven = new Thread(()->{
            lock.lock();
            try{
                while(n<100){
                    System.out.println(n++);
                    conditioneven.signalAll();
                    conditionodd.await();
                }

            } catch (InterruptedException e) {
                e.printStackTrace();
            } finally {
               lock.unlock();
            }
        });

        Thread thread=new Thread(()->{
           lock.lock();
           try{
               while(n<100){
                   System.out.println(n++);
                   conditionodd.signalAll();
                   conditioneven.await();
               }

           }catch (Exception e){
               e.printStackTrace();
           }finally {
               lock.unlock();
           }
        });
        thread.start();
        threadeven.start();
    }
}

使用synchronized实现

public class test {
    public static int n = 0;
    public static Object object = new Object();
    public static boolean even = true;

    public static void main(String[] args) {
        Thread threadeven = new Thread(() -> {
            synchronized (object) {
                while (n < 100) {
                    if (even) {
                        System.out.println(n++);
                        even = false;
                        object.notify();
                    }
                    try {
                        object.wait();
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            }
        });
        Thread threadodd = new Thread(() -> {
            synchronized (object) {
                while (n < 100) {
                    if (!even) {
                        System.out.println(n++);
                        even = true;
                        object.notify();
                    }
                    try {
                        object.wait();
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            }
        });
        threadeven.start();
        threadodd.start();
    }
}

注意：wait() await() 这些方法必须在同步代码块使用