JAVA Java多线程与并发库
2024-06-06 15:29:15
Java多线程与并发库
同步方式
import javax.xml.stream.events.StartDocument;public class TestSynchronized {public static void main(String[] args) {// TODO Auto-generated method stubTestSynchronized test = new TestSynchronized();test.init();}void init() {final Outputer outputer = new Outputer();new Thread(new Runnable(){@Overridepublic void run() {// TODO Auto-generated method stubwhile(true){try {Thread.sleep(10);} catch (Exception e) {// TODO: handle exceptione.printStackTrace();}outputer.Output("wangyuyuyuyuyuyuyuyu");}}}){}.start();new Thread(new Runnable() {@Overridepublic void run() {// TODO Auto-generated method stubwhile(true){try {Thread.sleep(10);} catch (Exception e) {// TODO: handle exceptione.printStackTrace();}outputer.Output("zhouzhanzhaozhaozhaozhao");}}}){}.start();}class Outputer{final static String lockKey = "lock";//定义输出函数//第一种方式，提供某个锁public void Output(String name){int len = name.length();synchronized (lockKey) {for (int i = 0; i < len; i++){System.out.print(name.charAt(i));}System.out.println();}}//第二种方式，锁住自己public void Output1(String name){int len = name.length();synchronized (this) { //也可以用Outputer.classfor (int i = 0; i < len; i++){System.out.print(name.charAt(i));}System.out.println();}}//第三种方式，函数前面加关键字synchronizedpublic synchronized void Output2(String name){int len = name.length();for (int i = 0; i < len; i++){System.out.print(name.charAt(i));}System.out.println();}}}
定时器Timer
import java.util.Timer;
import java.util.TimerTask;public class TimerTest {public static void main(String[] args){new Timer().schedule(new TimerTask(){@Overridepublic void run() {// TODO Auto-generated method stubSystem.out.println("boom");}}, 3000);}
}
HashMap存储线程
import java.util.HashMap;
import java.util.Map;
import java.util.Random;public class TestThreadMap {private static HashMap<Thread, Integer> map = new HashMap<Thread, Integer>();public static void main(String[] args) {//TestThreadMap testThreadMap = new TestThreadMap();for (int i = 0; i < 2; i++) {new Thread(new Runnable() {@Overridepublic void run() {// TODO Auto-generated method stubint data = new Random().nextInt();map.put(Thread.currentThread(), data);new A().Get();new B().Get();}}){}.start();}}static class A{public void Get(){int data = map.get(Thread.currentThread());System.out.println("A from " + Thread.currentThread().getName() + " get data " + data);}}static class B{public void Get(){int data = map.get(Thread.currentThread());System.out.println("B from " + Thread.currentThread().getName() + " get data " + data);}}
}
ThreadLocal类似HashMap存储线程
import java.util.HashMap;
import java.util.Map;
import java.util.Random;public class TestThreadMap {private static HashMap<Thread, Integer> map = new HashMap<Thread, Integer>();public static void main(String[] args) {//TestThreadMap testThreadMap = new TestThreadMap();for (int i = 0; i < 2; i++) {new Thread(new Runnable() {@Overridepublic void run() {// TODO Auto-generated method stubint data = new Random().nextInt();map.put(Thread.currentThread(), data);new A().Get();new B().Get();}}){}.start();}}static class A{public void Get(){int data = map.get(Thread.currentThread());System.out.println("A from " + Thread.currentThread().getName() + " get data " + data);}}static class B{public void Get(){int data = map.get(Thread.currentThread());System.out.println("B from " + Thread.currentThread().getName() + " get data " + data);}}
}
import java.util.Random;public class TestThreadlocal_2 {public static void main(String[] args) {// TODO Auto-generated method stubfor (int i = 0; i < 2; i++){new Thread(new Runnable() {@Overridepublic void run() {// TODO Auto-generated method stubint data = new Random().nextInt();MyData.getInstance().setName("myData" + data);MyData.getInstance().setAge(data);new A().Get();new B().Get();}}){}.start();}}static class A{public void Get(){MyData data = MyData.getInstance();System.out.println("A from " + Thread.currentThread().getName() + " get data " + data.getName() + ", " + data.getAge());}}static class B{public void Get(){MyData data = MyData.getInstance();System.out.println("B from " + Thread.currentThread().getName() + " get data " + data.getName() + ", " + data.getAge());}}}class MyData{String name;int age;public static /*synchronized*/ MyData getInstance(){MyData instance = threadLocal.get();if (instance == null){ //不存在就创建一个与本线程有关的实例对象instance = new MyData();threadLocal.set(instance);}return instance;}//private static MyData instance = null;private static ThreadLocal<MyData> threadLocal = new ThreadLocal<MyData>();public String getName() {return name;}public void setName(String name) {this.name = name;}public int getAge() {return age;}public void setAge(int age) {this.age = age;}}
线程池
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;public class TestThreadPool {public static void main(String[] args){//固定大小的线程池ExecutorService threadPool = Executors.newFixedThreadPool(3);//缓存线程池，当线程不够用时会自动增加，多了会自动减少//ExecutorService threadPool = Executors.newCachedThreadPool();//单一线程池，线程死了可以重新启动//ExecutorService threadPool = Executors.newSingleThreadExecutor();for (int i = 1; i <= 10; i++){final int taskid = i;threadPool.execute(new Runnable() {@Overridepublic void run() {// TODO Auto-generated method stubfor (int j = 1; j <= 10; j++) {System.out.println(Thread.currentThread().getName() + " is loop of " + j + " for task of " + taskid);}}});}System.out.println("all have finished");threadPool.shutdown(); //线程池里没有任务了，线程池才关闭，等10个任务都完成后才关闭//threadPool.shutdownNow(); //一个线程完成之后立马关闭，此时只完成了3个任务/*//定时器线程池Executors.newScheduledThreadPool(3).schedule(new Runnable() {@Overridepublic void run() {// TODO Auto-generated method stubSystem.out.println("booming");}}, 6,TimeUnit.SECONDS); //多长时间后执行任务
*/ Executors.newScheduledThreadPool(3).scheduleAtFixedRate( //以固定频率执行任务new Runnable() {@Overridepublic void run() {// TODO Auto-generated method stubSystem.out.println("booming");}}, 6, //初始时间2, //间隔时间TimeUnit.SECONDS);}
}
锁Lock
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;import javax.xml.stream.events.StartDocument;public class TestLock {public static void main(String[] args) {// TODO Auto-generated method stubTestLock test = new TestLock();test.init();}void init() {final Outputer outputer = new Outputer();new Thread(new Runnable(){@Overridepublic void run() {// TODO Auto-generated method stubwhile(true){try {Thread.sleep(10);} catch (Exception e) {// TODO: handle exceptione.printStackTrace();}outputer.Output("wangyuyuyuyuyuyuyuyu");}}}){}.start();new Thread(new Runnable() {@Overridepublic void run() {// TODO Auto-generated method stubwhile(true){try {Thread.sleep(10);} catch (Exception e) {// TODO: handle exceptione.printStackTrace();}outputer.Output("zhouzhanzhaozhaozhaozhao");}}}){}.start();}class Outputer{Lock lock = new ReentrantLock(); //锁public void Output(String name){int len = name.length();lock.lock();try {for (int i = 0; i < len; i++){System.out.print(name.charAt(i));}System.out.println("");} finally{// TODO: handle exceptionlock.unlock();}}}}
读写锁ReadWriterLock
import java.util.HashMap;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;public class TestReadWriterLock {HashMap<String, Object> mp = new HashMap<String, Object>();private ReadWriteLock rwl = new ReentrantReadWriteLock();public Object Get(String key){rwl.readLock().lock();Object value = null;try {value = mp.get(key);if (value == null) {rwl.readLock().unlock();rwl.writeLock().lock();try {if (value == null){value = "aaa";}} finally {// TODO: handle finally clauserwl.writeLock().unlock();}rwl.readLock().lock();}} finally {rwl.readLock().unlock();}return value;}
}
信号灯Semaphere(控制当前运行的线程个数)
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Semaphore;
import java.util.function.IntToDoubleFunction;public class TestSemaphere {public static void main(String[] args) {// TODO Auto-generated method stub/*1.创建线程池*2.创建信号灯，大小为3 *3.循环10次，Runnable里设置信号灯acqure*/ExecutorService es = Executors.newCachedThreadPool();Semaphore semaphore = new Semaphore(3);for(int i = 0; i < 10; i++){es.execute(new Runnable() {@Overridepublic void run() {// TODO Auto-generated method stubtry {semaphore.acquire();} catch (Exception e) {// TODO: handle exceptione.printStackTrace();}System.out.println("线程" + Thread.currentThread().getName() + "进入");try {Thread.sleep((int)Math.random() * 10000);} catch (Exception e) {// TODO: handle exceptione.printStackTrace();}System.out.println("线程" + Thread.currentThread().getName() + "即将结束");semaphore.release();System.out.println("线程" + Thread.currentThread().getName() + "已结束");es.shutdown();}});}}}
数据交换Exchanger(当两个数据都到达后才能进行交换，否则阻塞)
import java.util.concurrent.Exchanger;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;public class TestExchanger {public static void main(String[] args) {// TODO Auto-generated method stubExecutorService es = Executors.newCachedThreadPool();Exchanger<String> exchanger = new Exchanger<String>();es.execute(new Runnable() {@Overridepublic void run() {// TODO Auto-generated method stubtry {String data1 = "x";System.out.println("线程" + Thread.currentThread().getName() + "正在把数据" + data1 + "发送出去");Thread.sleep((int)(Math.random() * 5000));String getData = exchanger.exchange(data1);System.out.println("线程" + Thread.currentThread().getName() + "接受到的数据为: " + getData);} catch (Exception e) {// TODO: handle exceptione.printStackTrace();}}});es.execute(new Runnable() {@Overridepublic void run() {// TODO Auto-generated method stubtry {String data1 = "y";System.out.println("线程" + Thread.currentThread().getName() + "正在把数据" + data1 + "发送出去");Thread.sleep((int)(Math.random() * 5000));String getData = exchanger.exchange(data1);System.out.println("线程" + Thread.currentThread().getName() + "接受到的数据为: " + getData);} catch (Exception e) {// TODO: handle exceptione.printStackTrace();}}});}}
同步屏障CyclicBarrier(多个线程彼此等待，集合后再往后运行)
import java.util.concurrent.CyclicBarrier;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;public class TestCyclicBarrier {//多个线程彼此等待，集合后再运行public static void main(String[] args) {// TODO Auto-generated method stub//创建线程池和CyclicBarrier,同时运行多个线程，调用awaitExecutorService es = Executors.newCachedThreadPool();final CyclicBarrier cb = new CyclicBarrier(3);for (int i = 0; i < 3; i++){es.execute(new Runnable() {@Overridepublic void run() {// TODO Auto-generated method stubtry {Thread.sleep((int)(Math.random() * 1000));System.out.println("线程" + Thread.currentThread().getName() + "到达集合点1");System.out.println("当前有" + (cb.getNumberWaiting()+1) + "人在等待");cb.await();Thread.sleep((int)(Math.random() * 1000));System.out.println("线程" + Thread.currentThread().getName() + "到达集合点2");System.out.println("当前有" + (cb.getNumberWaiting()+1) + "人在等待");cb.await();Thread.sleep((int)(Math.random() * 1000));System.out.println("线程" + Thread.currentThread().getName() + "到达集合点3");System.out.println("当前有" + (cb.getNumberWaiting()+1) + "人在等待");cb.await();} catch (Exception e) {// TODO: handle exceptione.printStackTrace();}}});}es.shutdown();}}
CountDownLatch(类似倒计时计数器，当计数减为0时，所有等待者才开始执行)
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;public class TestCountDownLatch {//类似倒计时计数器，当计数减为0的时候，所有等待者才开始执行public static void main(String[] args) {// TODO Auto-generated method stub//创建两个计数器，一个为1，一个为3，代表一个裁判员，三个运动员，裁判员在未下达命令前运动员等待，下达命令后才执行//等三个运动员都到达终点后，裁判员才公布成绩ExecutorService es = Executors.newCachedThreadPool();CountDownLatch cdOrder = new CountDownLatch(1);CountDownLatch cdAnswer = new CountDownLatch(3);for (int i = 0; i < 3; i++) {final int id = i;es.execute(new Runnable() {@Overridepublic void run() {// TODO Auto-generated method stubtry {System.out.println("运动员" + id + "正准备接受命令");cdOrder.await();System.out.println("运动员"+ id + "接受到命令");Thread.sleep((int)(Math.random() * 5000));System.out.println("运动员" + id + "到达终点");cdAnswer.countDown();} catch (Exception e) {// TODO: handle exceptione.printStackTrace();}}});}try {Thread.sleep(1000);System.out.println("裁判员发出指令");cdOrder.countDown();System.out.println("裁判员等待所有运动员到达终点");cdAnswer.await();System.out.println("裁判员公布成绩");} catch (Exception e) {// TODO: handle exception}}}
Callable和Future
import java.util.Random;
import java.util.concurrent.Callable;
import java.util.concurrent.CompletionService;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorCompletionService;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;public class TestCallableAndFuture {public static void main(String[] args) throws InterruptedException, ExecutionException, TimeoutException{ExecutorService threadPool = Executors.newSingleThreadExecutor();Future future =threadPool.submit(new Callable<String>() {@Overridepublic String call() throws Exception {// TODO Auto-generated method stubThread.sleep(2000);return "hello";}});System.out.println("得到结果: " + future.get()); //callable完成任务返回结果，由future去拿，需要等待一段时间//System.out.println("得到结果: " + future.get(1, TimeUnit.SECONDS)); //要在规定的时间内得到结果，如果得不到就抛出异常//CompletionService 用于提交一组callable任务，并用take方法得到一个已完成任务的future对象ExecutorService threadPool2 = Executors.newFixedThreadPool(10);CompletionService<Integer> completionService = new ExecutorCompletionService<Integer>(threadPool2);for (int i = 1; i <= 10; i++){final int taskid = i;completionService.submit(new Callable<Integer>() {@Overridepublic Integer call() throws Exception {// TODO Auto-generated method stubtry {Thread.sleep(new Random().nextInt(5000));} catch (Exception e) {// TODO: handle exception}return taskid;}});}for (int i = 1; i <= 10; i++){System.out.println(completionService.take().get());}}}
阻塞队列ArrayBlockingQueue
import java.util.concurrent.ArrayBlockingQueue;public class TestArrayBlockingQueue {//阻塞队列当队列为空时take会阻塞，当队列满时put会阻塞//用两个阻塞队列模拟两个线程交替运行//两个阻塞队列大小均设置为1，其中一个放一个数据public static void main(String[] args) {// TODO Auto-generated method stubBusiness business = new Business();new Thread(new Runnable() {@Overridepublic void run() {// TODO Auto-generated method stubfor (int j = 1; j <= 10; j++) {business.Sub(j);}}}){}.start();for (int j = 1; j <= 10; j++) {business.Main(j);}}static class Business{ArrayBlockingQueue abq1 = new ArrayBlockingQueue(1);ArrayBlockingQueue abq2 = new ArrayBlockingQueue(1);public Business() {try {abq2.put(1);} catch (Exception e) {// TODO: handle exceptione.printStackTrace();}}public void Sub(int j){try {abq1.put(1);for (int i = 1; i <= 10; i++){System.out.println("sub thread " + i + " of loop " + j);}abq2.take();} catch (Exception e) {// TODO: handle exceptione.printStackTrace();}}public void Main(int j){try {abq2.put(1);for (int i = 1; i <= 10; i++){System.out.println("main thread " + i + " of loop " + j);}abq1.take();} catch (Exception e) {// TODO: handle exceptione.printStackTrace();}}}}
练习: 子线程运行10次，主线程运行20次，交替运行
public class prictice_1 {//子线程运行10次，主线程运行20次public static void main(String[] args) {// TODO Auto-generated method stubBusiness business = new Business();new Thread(new Runnable() {@Overridepublic void run() {// TODO Auto-generated method stubfor (int j = 1; j <= 10; j++) {business.Sub(j);}}}){}.start();for (int j = 1; j <= 10; j++) {business.Main(j);}}}
class Business{private boolean isSub = true;public synchronized void Sub(int j){while (!isSub) {try {this.wait();} catch (Exception e) {// TODO: handle exceptione.printStackTrace();}}for (int i = 1; i <= 10; i++){System.out.println("sub thread " + i + " of loop " + j);}isSub = false;this.notify();}public synchronized void Main(int j){while (isSub){try {this.wait();} catch (Exception e) {// TODO: handle exceptione.printStackTrace();}}for (int i = 1; i <= 20; i++){System.out.println("main thread " + i + " of loop " + j);}isSub = true;this.notify();}
}
JAVA Java多线程与并发库相关推荐
- Java多线程与并发库高级应用--18_传智播客_张孝祥_java5阻塞队列的应用
Java多线程与并发库高级应用--18_传智播客_张孝祥_java5阻塞队列的应用 原创:徐工 2018-5- 5 17.10 package cn.itcast.heima2; import jav ...
- Java多线程与并发库高级应用架构
张孝祥_Java多线程与并发库高级应用 [视频介绍:] Java线程是一项非常基本和重要的技术,在偏底层和偏技术的Java程序中不可避免地要使用到Java线程技术,特别是android手机程序和游戏开 ...
- Java 从多线程到并发编程（五）—— 线程调度 优先级倒置（反转） 阻塞 死锁 suspend
文章目录 前言 ´･ᴗ･` 线程调度策略 优先级倒置问题 优先级倒置解决方案 死锁 dead lock suspend 被阻塞的同时持有资源不放 是上述问题的诱因 总结 ´◡` 前言 ´･ᴗ･` 这一 ...
- Java多线程与并发库高级应用 学习笔记 1-9课
来源XXX,免得打广告嫌疑. http://www.cnblogs.com/whgw/archive/2011/10/03/2198506.html 今天看了文章才发现创建线程最佳方式为实现Runna ...
- java定时器 并发_【java多线程与并发库】— 定时器的应用 | 学步园
定时器的应用 1. 定时器主要涉及到两个类(java.util包中) @->public class Timer extendsObject (一种工具,线程用其安排以后在后台线程中执行的任务 ...
- Java面试——多线程高并发
1.什么是线程?线程和进程有什么区别? 答:线程是程序执行的最小执行单位,进程是资源分配的最小单位:一个进程就是一个应用程序,系统会为该进程分配资源空间,当多用户并发请求的时候,为每个用户创建一个进程 ...
- java 多进程多线程_Java并发编程原理与实战三：多线程与多进程的联系以及上下文切换所导致资源浪费问题...
一.进程 考虑一个场景:浏览器,网易云音乐以及notepad++ 三个软件只能顺序执行是怎样一种场景呢?另外,假如有两个程序A和B,程序A在执行到一半的过程中,需要读取大量的数据输入(I/O操作),而 ...
- 共同学习Java源代码-多线程与并发-FutureTask类(三)
static final class WaitNode { volatile Thread thread; volatile WaitNode next; ...
- Java多线程与线程并发库高级应用笔记
以下内容是学习张老师Java多线程与线程并发库高级应用时所做的笔记,很有用 网络编辑器直接复制Word文档排版有点乱,提供原始文件下载 先看源文件概貌 张孝祥_Java多线程与并发库高级应用 [视频介 ...
最新文章
- 金蝶应收应付模块流程_金蝶KIS专业版应收应付的系统亮点功能
- 如何成为一个卓越的程序员
- Linux 下监控系统几个重要组件
- 使用Template时 typename 关键字的用法
- 简而言之，JUnit：测试结构
- php链接数据库实行增删查改_最方便最简单的php操作mysql的增删改查方法
- swagger访问开关配置
- 控制流图｜圈复杂度｜基本复杂度
- POJ2403 Hay Points
- tp5之允许跨域请求
- 论文笔记_S2D.73_ICCV2021_单目深度估计的可解释深度网络研究
- PHP操作文件的常用函数
- 电脑小技巧：怎么取消电脑开机密码
- 前端开发中spa的优缺点_使用单Spa开发和部署微前端
- JavaScript:实现PigeonHoleSort鸽巢排序算法（附完整源码）
- 第二章 从优化业务流程谈信息集成的必要性
- [小技巧] git: Your branch and 'origin/master' have diverged
- 鲁大师发布2022半年报手机UI排行榜,vivo OriginOS成为最流畅UI
- 精仿互站模板 友价源码商城T5内核二次开发运营版
- 测试 必用 工具（测试工具知多少）