Spring线程池开发实战

作者：chszs，转载需注明。

作者博客主页：http://blog.csdn.net/chszs

本文提供了三个Spring多线程开发的例子，由浅入深，由于例子一目了然，所以并未做过多的解释。诸位一看便知。

前提条件：

1）在Eclipse创建一个Java项目，我取名为SpringThreadDemo。
2）项目所需的JAR包如图所示：

下面开始。

注：项目源码已经托管到GitHub，地址：https://github.com/chszs/SpringThreadDemo

例子1：Spring结合Java线程。

通过继承Thread创建一个简单的Java线程，然后使用@Component让Spring容器管理此线程，Bean的范围必须是prototype，因此每个请求都会返回一个新实例，运行每个单独的线程。

PrintThread.java

package com.chszs.thread;

import org.springframework.stereotype.Component;
import org.springframework.context.annotation.Scope;

@Component
@Scope("prototype")
public class PrintThread extends Thread{
        @Override
        public void run(){
                System.out.println(getName() + " is running.");
                try{
                        Thread.sleep(5000);
                }catch(InterruptedException e){
                        e.printStackTrace();
                }
                System.out.println(getName() + " is running again.");
        }
}

AppConfig.java

package com.chszs.config;

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;

@Configuration
@ComponentScan(basePackages="com.chszs.thread")
public class AppConfig {
}

App.java

package com.chszs;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;

import com.chszs.config.AppConfig;
import com.chszs.thread.PrintThread;

public class App {
        public static void main(String[] args){
                ApplicationContext ctx = 
            new AnnotationConfigApplicationContext(AppConfig.class);
                PrintThread printThread1 = (PrintThread)ctx.getBean("printThread");
                printThread1.setName("Thread 1");
                
                PrintThread printThread2 = (PrintThread)ctx.getBean("printThread");
                printThread2.setName("Thread 2");
                
                PrintThread printThread3 = (PrintThread)ctx.getBean("printThread");
                printThread3.setName("Thread 3");
                
                PrintThread printThread4 = (PrintThread)ctx.getBean("printThread");
                printThread4.setName("Thread 4");
                
                PrintThread printThread5 = (PrintThread)ctx.getBean("printThread");
                printThread5.setName("Thread 5");
                
                printThread1.start();
                printThread2.start();
                printThread3.start();
                printThread4.start();
                printThread5.start();
        }
}

输出：

Thread 1 is running.
Thread 2 is running.
Thread 4 is running.
Thread 5 is running.
Thread 3 is running.
Thread 2 is running again.
Thread 1 is running again.
Thread 5 is running again.
Thread 4 is running again.
Thread 3 is running again.

例子2：Spring线程池结合非Spring托管Bean。

使用Spring的ThreadPoolTaskExecutor类创建一个线程池。执行线程无需受Spring容器的管理。

PrintTask.java

package com.chszs.thread;

public class PrintTask implements Runnable{
        String name;
        public PrintTask(String name){
                this.name = name;
        }
        @Override
        public void run() {
                System.out.println(name + " is running.");
                try{
                        Thread.sleep(5000);
                }catch(InterruptedException e){
                        e.printStackTrace();
                }
                System.out.println(name + " is running again.");
        }
        
}

Spring-Config.xml

<beans xmlns="http://www.springframework.org/schema/beans"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
        xmlns:context="http://www.springframework.org/schema/context"
        xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context-3.1.xsd">
        
        <bean id="taskExecutor" 
        class="org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor">
                <property name="corePoolSize" value="5" />
                <property name="maxPoolSize" value="10" />
                <property name="WaitForTasksToCompleteOnShutdown" value="true" />
        </bean>
</beans>

注意这个Spring配置文件的位置，如图所示：

App1.java

package com.chszs;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;

import com.chszs.thread.PrintTask;

public class App1 {

        public static void main(String[] args) {
                ApplicationContext ctx = 
            new ClassPathXmlApplicationContext("resources/Spring-Config.xml");
                ThreadPoolTaskExecutor taskExecutor =
            (ThreadPoolTaskExecutor)ctx.getBean("taskExecutor");
                taskExecutor.execute(new PrintTask("Thread 1"));
                taskExecutor.execute(new PrintTask("Thread 2"));
                taskExecutor.execute(new PrintTask("Thread 3"));
                taskExecutor.execute(new PrintTask("Thread 4"));
                taskExecutor.execute(new PrintTask("Thread 5"));
                // 检查活动的线程，如果活动线程数为0则关闭线程池
                for(;;){
                        int count = taskExecutor.getActiveCount();
                        System.out.println("Active Threads : " + count);
                        try{
                                Thread.sleep(1000);
                        }catch(InterruptedException e){
                                e.printStackTrace();
                        }
                        if(count==0){
                                taskExecutor.shutdown();
                                break;
                        }
                }
        }

}

输出：

Thread 1 is running.
Thread 2 is running.
Thread 3 is running.
Thread 4 is running.
Active Threads : 4
Thread 5 is running.
Active Threads : 5
Active Threads : 5
Active Threads : 5
Active Threads : 5
Active Threads : 5
Thread 4 is running again.
Thread 2 is running again.
Thread 3 is running again.
Thread 1 is running again.
Thread 5 is running again.
Active Threads : 0

作者：chszs，转载需注明。博客主页：http://blog.csdn.net/chszs

例子3：Spring线程池结合Spring托管Bean。

本例仍然使用ThreadPoolTaskExecutor类，并使用@Component注释声明Spring的托管Bean。
下面的例子PrintTask2是Spring的托管Bean，使用@Autowired注释简化代码。

PrintTask2.java

package com.chszs.thread;

import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Component;

@Component
@Scope("prototype")
public class PrintTask2 implements Runnable {
        String name;

        public void setName(String name) {
                this.name = name;
        }
        
        @Override
        public void run(){
                System.out.println(name + " is running.");
                try{
                        Thread.sleep(5000);
                }catch(InterruptedException e){
                        e.printStackTrace();
                }
                System.out.println(name + " is running again.");
        }
}

AppConfig.java

package com.chszs.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;

@Configuration
@ComponentScan(basePackages="com.chszs.thread")
public class AppConfig {
        @Bean
        public ThreadPoolTaskExecutor taskExecutor(){
                ThreadPoolTaskExecutor pool = new ThreadPoolTaskExecutor();
                pool.setCorePoolSize(5);
                pool.setMaxPoolSize(10);
                pool.setWaitForTasksToCompleteOnShutdown(true);
                return pool;
        }
}

App2.java

package com.chszs;

import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;

import com.chszs.config.AppConfig;
import com.chszs.thread.PrintTask2;

public class App2 {
        public static void main(String[] args) {
                ApplicationContext ctx = 
            new AnnotationConfigApplicationContext(AppConfig.class);
                ThreadPoolTaskExecutor taskExecutor =
            (ThreadPoolTaskExecutor)ctx.getBean("taskExecutor");
                
                PrintTask2 printTask1 = (PrintTask2)ctx.getBean("printTask2");
                printTask1.setName("Thread 1");
                taskExecutor.execute(printTask1);
                
                PrintTask2 printTask2 = (PrintTask2)ctx.getBean("printTask2");
                printTask2.setName("Thread 2");
                taskExecutor.execute(printTask2);
                
                PrintTask2 printTask3 = (PrintTask2)ctx.getBean("printTask2");
                printTask3.setName("Thread 3");
                taskExecutor.execute(printTask3);
                
                for(;;){
                        int count = taskExecutor.getActiveCount();
                        System.out.println("Active Threads : " + count);
                        try{
                                Thread.sleep(1000);
                        }catch(InterruptedException e){
                                e.printStackTrace();
                        }
                        if(count==0){
                                taskExecutor.shutdown();
                                break;
                        }
                }
        }

}

输出：

Thread 1 is running.
Thread 2 is running.
Active Threads : 2
Thread 3 is running.
Active Threads : 3
Active Threads : 3
Active Threads : 3
Active Threads : 3
Thread 1 is running again.
Thread 2 is running again.
Thread 3 is running again.
Active Threads : 1
Active Threads : 0

从这三个简单的实例中，你是不是发现了Spring框架在多线程方面的强大之处！！