l  休眠唤醒方式：

Object的wait、notify、notifyAll

Condition的await、signal、signalAll

l  CountDownLatch：用于某个线程A等待若干个其他线程执行完之后，它才执行

l  CyclicBarrier：一组线程等待至某个状态之后再全部同时执行

l  Semaphore：用于控制对某组资源的访问权限

Object的wait、notify、notifyAll

public class WaitNotifyRunnable{

private Object obj = new Object();

private Integer i=0;

public void odd() {

while(i<10){

synchronized (obj){

if(i%2 == 1){

System.out.println("奇数："+i);

i++;

obj.notify();

} else {

try {

obj.wait();

} catch (InterruptedException e) {

e.printStackTrace();

}

}

}

}

}

public void even(){

while(i<10){

synchronized (obj){

if(i%2 == 0){

System.out.println("偶数："+i);

i++;

obj.notify();

} else {

try {

obj.wait();

} catch (InterruptedException e) {

e.printStackTrace();

}

}

}

}

}

public static void main(String[] args){

final WaitNotifyRunnable runnable = new WaitNotifyRunnable();

Thread t1 = new Thread(new Runnable() {

public void run() {

runnable.odd();

}

}, "偶数线程");

Thread t2 = new Thread(new Runnable() {

public void run() {

runnable.even();

}

}, "奇数线程");

t1.start();

t2.start();

}

}

Condition的await、signal、signalAll

import java.util.concurrent.locks.Condition;

import java.util.concurrent.locks.Lock;

import java.util.concurrent.locks.ReentrantLock;

public class WaitNotifyRunnable{

private Lock lock = new ReentrantLock();

private Condition condition = lock.newCondition();

private Integer i=0;

public void odd() {

while(i<10){

lock.lock();

try{

if(i%2 == 1){

System.out.println("奇数："+i);

i++;

condition.signal();

} else {

condition.await();

}

} catch (InterruptedException e) {

e.printStackTrace();

} finally {

lock.unlock();

}

}

}

public void even(){

while(i<10){

lock.lock();

try{

if(i%2 == 0){

System.out.println("偶数："+i);

i++;

condition.signal();

} else {

condition.await();

}

} catch (InterruptedException e) {

e.printStackTrace();

} finally {

lock.unlock();

}

}

}

public static void main(String[] args){

final WaitNotifyRunnable runnable = new WaitNotifyRunnable();

Thread t1 = new Thread(new Runnable() {

public void run() {

runnable.odd();

}

}, "偶数线程");

Thread t2 = new Thread(new Runnable() {

public void run() {

runnable.even();

}

}, "奇数线程");

t1.start();

t2.start();

}

}

Object和Condition休眠唤醒区别

l  object wait()必须在synchronized(同步锁)下使用，

l  object wait()必须要通过Nodify()方法进行唤醒

l  condition await() 必须和Lock(互斥锁/共享锁)配合使用

l  condition await() 必须通过 signal() 方法进行唤醒

CountDownLatch方式

CountDownLatch这个类能够使一个线程等待其他线程完成各自的工作后再执行。

CountDownLatch是通过一个计数器来实现的，计数器的初始值为线程的数量

每当一个线程完成了自己的任务后，计数器的值就会减1。当计数器值到达0时，它表示所有的线程已经完成了任务，然后在闭锁上等待的线程就可以恢复执行任务

import java.util.concurrent.CountDownLatch;

public class CoachRecerDemo {

private CountDownLatch countDownLatch=new CountDownLatch(3); //设置要等待的运动员

//运动员方法

public void racer(){

//获取线程名

String name=Thread.currentThread().getName();

System.out.println(name+"正在准备....");

try {

Thread.sleep(1000);

} catch (InterruptedException e) {

e.printStackTrace();

}

System.out.println(name+"准备完毕");

countDownLatch.countDown();//-1

}

//教练方法

public void coach(){

String name=Thread.currentThread().getName();

System.out.println(name+"等待运动员准备...");

try {

countDownLatch.await();

} catch (InterruptedException e) {

e.printStackTrace();

}

System.out.println("所有运动员就绪，"+name+"开始训练");

}

public static void main(String[] args) {

//1.创建CoachRecerDemo 实例

CoachRecerDemo coachRecerDemo=new CoachRecerDemo();

//2.创建三个线程对象

Thread thread1=new Thread(new Runnable(){

public void run() {

coachRecerDemo.racer();

}

},"运动员1");

Thread thread2=new Thread(new Runnable() {

public void run() {

coachRecerDemo.racer();

}

},"运动员2");

Thread thread3=new Thread(new Runnable() {

public void run() {

coachRecerDemo.racer();

}

},"运动员3");

//3.教练

Thread thread4=new Thread(new Runnable() {

public void run() {

coachRecerDemo.coach();

}

},"教练");

thread4.start();

thread1.start();

thread2.start();

thread3.start();

}

}

CyclicBarrier方式

CyclicBarrier是在java1.5被引入的，存在于java.util.concurrent包下。

CyclicBarrier实现让一组线程等待至某个状态之后再全部同时执行。

CyclicBarrier底层是三个线程同时启动

import java.util.Date;

import java.util.concurrent.BrokenBarrierException;

import java.util.concurrent.CyclicBarrier;

public class ThreeThreadStartDemo {

private CyclicBarrier cyclicBarrier = new CyclicBarrier(3);// 所有参与启动的线程数

public void startThread() {

// 打印线程准备启动

String name = Thread.currentThread().getName();

System.out.println(name + "正在准备...");

// 2.调用CyclicBarriar的await方法等待线程准备完毕

try {

cyclicBarrier.await();

} catch (InterruptedException | BrokenBarrierException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

// 3.打印线程启动信息

System.out.println(name + "已经启动完毕" + new Date().getTime());

}

public static void main(String[] args) {

final ThreeThreadStartDemo threadStartDemo = new ThreeThreadStartDemo();

Thread thread1 = new Thread(new Runnable() {

public void run() {

threadStartDemo.startThread();

}

});

Thread thread2 = new Thread(new Runnable() {

public void run() {

threadStartDemo.startThread();

}

});

Thread thread3 = new Thread(new Runnable() {

public void run() {

threadStartDemo.startThread();

}

});

thread1.start();

thread2.start();

thread3.start();

}

}

Semaphore方式

Semaphore是在java1.5被引入的，存在于java.util.concurrent包下。

Semaphore用于控制对某组资源的访问权限。

import java.util.concurrent.Semaphore;

public class WorkerMachineDemo {

static class Work implements Runnable {

private int workerNum;

private Semaphore semaphore;

public Work(int workerNum, Semaphore semaphore) {

this.workerNum = workerNum;

this.semaphore = semaphore;

}

public void run() {

// 1.获取机器

// 2.打印工人获取到机器，开始工作

// 3.线程睡眠1000毫秒

// 4.使用完毕

try {

semaphore.acquire();

String name = Thread.currentThread().getName();

System.out.println(name + "获取到机器，开始工作");

Thread.sleep(1000);

semaphore.release();

System.out.println(name + "使用完毕，释放机器！");

} catch (Exception e) {

// TODO: handle exception

}

}

}

public static void main(String[] args) {

int works = 8;

Semaphore semaphore = new Semaphore(3);// 机器数

for (int i = 0; i < works; i++) {

new Thread(new Work(i, semaphore)).start();

}

}

}

sleep和wait区别：

wait和notify区别

wait和notify都是Object中的方法

wait和notify执行前线程都必须获得对象锁

wait的作用是使当前线程进行等待

notify的作用是通知其他等待当前线程的对象锁的线程