Spring线程池由浅入深的3个示例

作者博客主页：http://blog.****.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

1. package com.chszs.thread;
2. import org.springframework.stereotype.Component;
3. import org.springframework.context.annotation.Scope;
4. @Component
5. @Scope("prototype")
6. public class PrintThread extends Thread{
7. @Override
8. public void run(){
9. System.out.println(getName() + " is running.");
10. try{
11. Thread.sleep(5000);
12. }catch(InterruptedException e){
13. e.printStackTrace();
14. }
15. System.out.println(getName() + " is running again.");
16. }
17. }

AppConfig.java

1. package com.chszs.config;
2. import org.springframework.context.annotation.ComponentScan;
3. import org.springframework.context.annotation.Configuration;
4. @Configuration
5. @ComponentScan(basePackages="com.chszs.thread")
6. public class AppConfig {
7. }

App.java

1. package com.chszs;
2. import org.springframework.context.ApplicationContext;
3. import org.springframework.context.annotation.AnnotationConfigApplicationContext;
4. import com.chszs.config.AppConfig;
5. import com.chszs.thread.PrintThread;
6. public class App {
7. public static void main(String[] args){
8. ApplicationContext ctx =
9. new AnnotationConfigApplicationContext(AppConfig.class);
10. PrintThread printThread1 = (PrintThread)ctx.getBean("printThread");
11. printThread1.setName("Thread 1");
12. PrintThread printThread2 = (PrintThread)ctx.getBean("printThread");
13. printThread2.setName("Thread 2");
14. PrintThread printThread3 = (PrintThread)ctx.getBean("printThread");
15. printThread3.setName("Thread 3");
16. PrintThread printThread4 = (PrintThread)ctx.getBean("printThread");
17. printThread4.setName("Thread 4");
18. PrintThread printThread5 = (PrintThread)ctx.getBean("printThread");
19. printThread5.setName("Thread 5");
20. printThread1.start();
21. printThread2.start();
22. printThread3.start();
23. printThread4.start();
24. printThread5.start();
25. }
26. }

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

1. package com.chszs.thread;
2. public class PrintTask implements Runnable{
3. String name;
4. public PrintTask(String name){
5. this.name = name;
6. }
7. @Override
8. public void run() {
9. System.out.println(name + " is running.");
10. try{
11. Thread.sleep(5000);
12. }catch(InterruptedException e){
13. e.printStackTrace();
14. }
15. System.out.println(name + " is running again.");
16. }
17. }

Spring-Config.xml

1. <beans xmlns="http://www.springframework.org/schema/beans"
2. xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
3. xmlns:context="http://www.springframework.org/schema/context"
4. xsi:schemaLocation="http://www.springframework.org/schema/beans
5. http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
6. http://www.springframework.org/schema/context
7. http://www.springframework.org/schema/context/spring-context-3.1.xsd">
8. <bean id="taskExecutor"
9. class="org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor">
10. <property name="corePoolSize" value="5" />
11. <property name="maxPoolSize" value="10" />
12. <property name="WaitForTasksToCompleteOnShutdown" value="true" />
13. </bean>
14. </beans>

注意这个Spring配置文件的位置，如图所示：

App1.java

1. package com.chszs;
2. import org.springframework.context.ApplicationContext;
3. import org.springframework.context.support.ClassPathXmlApplicationContext;
4. import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
5. import com.chszs.thread.PrintTask;
6. public class App1 {
7. public static void main(String[] args) {
8. ApplicationContext ctx =
9. new ClassPathXmlApplicationContext("resources/Spring-Config.xml");
10. ThreadPoolTaskExecutor taskExecutor =
11. (ThreadPoolTaskExecutor)ctx.getBean("taskExecutor");
12. taskExecutor.execute(new PrintTask("Thread 1"));
13. taskExecutor.execute(new PrintTask("Thread 2"));
14. taskExecutor.execute(new PrintTask("Thread 3"));
15. taskExecutor.execute(new PrintTask("Thread 4"));
16. taskExecutor.execute(new PrintTask("Thread 5"));
17. // 检查活动的线程，如果活动线程数为0则关闭线程池
18. for(;;){
19. int count = taskExecutor.getActiveCount();
20. System.out.println("Active Threads : " + count);
21. try{
22. Thread.sleep(1000);
23. }catch(InterruptedException e){
24. e.printStackTrace();
25. }
26. if(count==0){
27. taskExecutor.shutdown();
28. break;
29. }
30. }
31. }
32. }

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.****.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

1. package com.chszs.thread;
2. import org.springframework.context.annotation.Scope;
3. import org.springframework.stereotype.Component;
4. @Component
5. @Scope("prototype")
6. public class PrintTask2 implements Runnable {
7. String name;
8. public void setName(String name) {
9. this.name = name;
10. }
11. @Override
12. public void run(){
13. System.out.println(name + " is running.");
14. try{
15. Thread.sleep(5000);
16. }catch(InterruptedException e){
17. e.printStackTrace();
18. }
19. System.out.println(name + " is running again.");
20. }
21. }

AppConfig.java

1. package com.chszs.config;
2. import org.springframework.context.annotation.Bean;
3. import org.springframework.context.annotation.ComponentScan;
4. import org.springframework.context.annotation.Configuration;
5. import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
6. @Configuration
7. @ComponentScan(basePackages="com.chszs.thread")
8. public class AppConfig {
9. @Bean
10. public ThreadPoolTaskExecutor taskExecutor(){
11. ThreadPoolTaskExecutor pool = new ThreadPoolTaskExecutor();
12. pool.setCorePoolSize(5);
13. pool.setMaxPoolSize(10);
14. pool.setWaitForTasksToCompleteOnShutdown(true);
15. return pool;
16. }
17. }

App2.java

1. package com.chszs;
2. import org.springframework.context.ApplicationContext;
3. import org.springframework.context.annotation.AnnotationConfigApplicationContext;
4. import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
5. import com.chszs.config.AppConfig;
6. import com.chszs.thread.PrintTask2;
7. public class App2 {
8. public static void main(String[] args) {
9. ApplicationContext ctx =
10. new AnnotationConfigApplicationContext(AppConfig.class);
11. ThreadPoolTaskExecutor taskExecutor =
12. (ThreadPoolTaskExecutor)ctx.getBean("taskExecutor");
13. PrintTask2 printTask1 = (PrintTask2)ctx.getBean("printTask2");
14. printTask1.setName("Thread 1");
15. taskExecutor.execute(printTask1);
16. PrintTask2 printTask2 = (PrintTask2)ctx.getBean("printTask2");
17. printTask2.setName("Thread 2");
18. taskExecutor.execute(printTask2);
19. PrintTask2 printTask3 = (PrintTask2)ctx.getBean("printTask2");
20. printTask3.setName("Thread 3");
21. taskExecutor.execute(printTask3);
22. for(;;){
23. int count = taskExecutor.getActiveCount();
24. System.out.println("Active Threads : " + count);
25. try{
26. Thread.sleep(1000);
27. }catch(InterruptedException e){
28. e.printStackTrace();
29. }
30. if(count==0){
31. taskExecutor.shutdown();
32. break;
33. }
34. }
35. }
36. }

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！！