Phaser的简单使用

标签：Phaser 简单 boot springframework phaser 使用 println org

Phaser属于jdk1.7新增的同步工具类

使用CountDownLatch,主线程执行的任务要等副线程执行完毕才可执行

Phaser达到同等的效果

package com.java.test.phaser;

import org.junit.Test;

import java.util.Random;
import java.util.concurrent.Phaser;

/**
 * @Description:
 * @Author: Yourheart
 * @Create: 2023/1/4 23:45
 */
public class PhaserTest {

    @Test
    public void test(){

        Phaser phaser = new Phaser(5);

        for (int i = 0; i < 5; i++) {
            new Thread("线程-" + (i + 1)) {
                private final Random random = new Random();
                @Override
                public void run() {
                    System.out.println(getName() + " - 开始运行");
                    try {
                        Thread.sleep(random.nextInt(1000));
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                    System.out.println(getName() + " - 运行结束");
                    phaser.arrive();
                }
            }.start();
        }
        System.out.println("线程启动完毕");
        phaser.awaitAdvance(phaser.getPhase());
        //用Phaser替代CyclicBarrier考虑前面讲CyclicBarrier时，10个工程师去公司应聘的例子，也可以用Phaser实现，代码基本类似。
        System.out.println("线程运行结束");


    }
}

　　pom文件

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.java</groupId>
    <artifactId>test-study</artifactId>
    <version>1.0-SNAPSHOT</version>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.1.RELEASE</version>
        <relativePath/>
    </parent>

    <dependencies>
        <!--tomcat容器-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <!--lombok依赖-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.16</version>
        </dependency>
        <!--引入junit单元测试依赖-->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>
        <!--判断空的用法  -->
        <dependency>
            <groupId>commons-lang</groupId>
            <artifactId>commons-lang</artifactId>
            <version>2.6</version>
        </dependency>

        <!-- https://mvnrepository.com/artifact/com.oracle.database.jdbc/ojdbc8 -->
        <dependency>
            <groupId>com.oracle.database.jdbc</groupId>
            <artifactId>ojdbc8</artifactId>
            <version>12.2.0.1</version>
        </dependency>
        <!--springboot整合mybatis-->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.1.2</version>
        </dependency>

        <!--添加fastjson依赖-->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.70</version>
        </dependency>
        <!-- 热部署模块 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <optional>true</optional> <!-- 这个需要为 true 热部署才有效 -->
        </dependency>
        <!--ThreadFactoryBuilder的依赖包,多线程使用-->
        <dependency>
            <groupId>com.google.guava</groupId>
            <artifactId>guava</artifactId>
            <version>30.1-jre</version>
        </dependency>

        <!--Lists.partition要用的依赖-->
        <dependency>
            <groupId>com.google.guava</groupId>
            <artifactId>guava</artifactId>
            <version>21.0</version>
        </dependency>
       <!--ListUtils.partition使用的依赖-->
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-collections4</artifactId>
            <version>4.4</version>
        </dependency>
        <!--操作redis的依赖-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-pool2</artifactId>
        </dependency>
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
            <version>3.9</version>
        </dependency>


    </dependencies>


    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
        <finalName>study</finalName>
    </build>


</project>

View Code

实现一起去食堂吃饭，吃饭完在一起去上课

单纯的使用测试注解，会没法执行完成，使用了定时任务实现

package com.java.test.phaser;

import java.util.Random;
import java.util.concurrent.Phaser;

/**
 * @Description
 * @Author qiuxie
 * @Date 2023/1/5 22:08
 */
public class PhaserThread extends Thread{

    private final Phaser phaser;
    private final Random random = new Random();

    public PhaserThread(String name, Phaser phaser) {
        super(name);
        this.phaser = phaser;
    }


    @Override
    public void run() {
        System.out.println(getName() + " - 起床");
        slowly();
        System.out.println(getName() + " - 洗漱完毕");
        // 到达同步点，等待其他线程
        phaser.arriveAndAwaitAdvance();

        System.out.println(getName() + " - 食堂打完菜开始吃饭");
        slowly();
        System.out.println(getName() + " - 吃饭结束");
        // 到达同步点，等待其他线程
        phaser.arriveAndAwaitAdvance();

        System.out.println(getName() + " - 准备出发去教室");
        slowly();
        System.out.println(getName() + " - 全部到达教室");
    }

    private void slowly() {
        try {
            Thread.sleep(random.nextInt(6000));
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
}

package com.java.test.phaser;

import org.springframework.context.annotation.Configuration;
import org.springframework.scheduling.annotation.Async;
import org.springframework.scheduling.annotation.EnableScheduling;
import org.springframework.scheduling.annotation.Scheduled;

import java.util.concurrent.Phaser;

/**
 * @Description
 * @Author qiuxie
 * @Date 2023/1/5 22:08
 */
@Configuration      //1.主要用于标记配置类，兼备Component的效果。
@EnableScheduling   // 2.开启定时任务
public class PhaserThreadTest {

    /**
     * 当天的17点31分0秒执行
     */
    @Scheduled(cron = "0 31 17 * * *")
    @Async
    public void test(){

        Phaser phaser = new Phaser(5);
        for (int i = 0; i <5 ; i++) {
            new PhaserThread("线程-"+(i+1),phaser).start();
        }
        phaser.awaitAdvance(phaser.getPhase());

    }
}

　特性1 动态调整线程个数