线程池对于执行同步和异步过程非常重要。 本文介绍如何使用Spring开发和监视线程池服务。 创建线程池已通过两种替代方法进行了说明。

二手技术 ：

JDK 1.6.0_21
Spring3.0.5
Maven的3.0.2

步骤1：建立已完成的专案

创建一个Maven项目，如下所示。 （可以使用Maven或IDE插件来创建它）。

步骤2：图书馆

Spring依赖项已添加到Maven的pom.xml中。

<!-- Spring 3 dependencies -->
<dependency><groupId>org.springframework</groupId><artifactId>spring-core</artifactId><version>${spring.version}</version>
</dependency>
<dependency><groupId>org.springframework</groupId><artifactId>spring-context</artifactId><version>${spring.version}</version>
</dependency>

为了创建runnable-jar，可以使用以下插件。

<plugin><groupId>org.apache.maven.plugins</groupId><artifactId>maven-shade-plugin</artifactId><version>1.3.1</version><executions><execution><phase>package</phase><goals><goal>shade</goal></goals><configuration><transformers><transformerimplementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer"><mainClass>com.otv.exe.Application</mainClass></transformer><transformerimplementation="org.apache.maven.plugins.shade.resource.AppendingTransformer"><resource>META-INF/spring.handlers</resource></transformer><transformerimplementation="org.apache.maven.plugins.shade.resource.AppendingTransformer"><resource>META-INF/spring.schemas</resource></transformer></transformers></configuration></execution></executions>
</plugin>

第3步：创建任务班

通过实现Runnable接口可以创建一个新的TestTask类。 此类显示要执行的任务。

package com.otv.task;import org.apache.log4j.Logger;/*** @author onlinetechvision.com* @since 17 Oct 2011* @version 1.0.0**/
public class TestTask implements Runnable {private static Logger log = Logger.getLogger(TestTask.class);String taskName;public TestTask() {}public TestTask(String taskName) {this.taskName = taskName;}public void run() {try {log.debug(this.taskName + " : is started.");Thread.sleep(10000);log.debug(this.taskName + " : is completed.");} catch (InterruptedException e) {log.error(this.taskName + " : is not completed!");e.printStackTrace();}}@Overridepublic String toString() {return (getTaskName());}public String getTaskName() {return taskName;}public void setTaskName(String taskName) {this.taskName = taskName;}
}

步骤4：建立TestRejectedExecutionHandler类别

通过实现RejectedExecutionHandler接口来创建TestRejectedExecutionHandler类。 如果没有空闲线程并且队列溢出，任务将被拒绝。 此类处理被拒绝的任务。

package com.otv.handler;import java.util.concurrent.RejectedExecutionHandler;
import java.util.concurrent.ThreadPoolExecutor;import org.apache.log4j.Logger;/*** @author onlinetechvision.com* @since 17 Oct 2011* @version 1.0.0**/
public class TestRejectedExecutionHandler implements RejectedExecutionHandler {private static Logger log = Logger.getLogger(TestRejectedExecutionHandler.class);public void rejectedExecution(Runnable runnable, ThreadPoolExecutor executor) {log.debug(runnable.toString() + " : has been rejected");}
}

步骤5：建立ITestThreadPoolExecutorService接口

ITestThreadPoolExecutorService接口已创建。

package com.otv.srv;import java.util.concurrent.ThreadPoolExecutor;import com.otv.handler.TestRejectedExecutionHandler;/*** @author onlinetechvision.com* @since 17 Oct 2011* @version 1.0.0**/
public interface ITestThreadPoolExecutorService {public ThreadPoolExecutor createNewThreadPool();public int getCorePoolSize();public void setCorePoolSize(int corePoolSize);public int getMaxPoolSize();public void setMaxPoolSize(int maximumPoolSize);public long getKeepAliveTime();public void setKeepAliveTime(long keepAliveTime);public int getQueueCapacity();public void setQueueCapacity(int queueCapacity);public TestRejectedExecutionHandler getTestRejectedExecutionHandler();public void setTestRejectedExecutionHandler(TestRejectedExecutionHandler testRejectedExecutionHandler);}

步骤6：建立TestThreadPoolExecutorService类别

通过实现ITestThreadPoolExecutorService接口来创建TestThreadPoolExecutorService类。 此类创建一个新的线程池。

package com.otv.srv;import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;import com.otv.handler.TestRejectedExecutionHandler;/*** @author onlinetechvision.com* @since 17 Oct 2011* @version 1.0.0**/
public class TestThreadPoolExecutorService implements ITestThreadPoolExecutorService {private int  corePoolSize;private int  maxPoolSize;private long keepAliveTime;private int  queueCapacity;TestRejectedExecutionHandler testRejectedExecutionHandler;public ThreadPoolExecutor createNewThreadPool() {ThreadPoolExecutor executor = new ThreadPoolExecutor(getCorePoolSize(),getMaxPoolSize(),getKeepAliveTime(),TimeUnit.SECONDS,new ArrayBlockingQueue(getQueueCapacity()),getTestRejectedExecutionHandler());return executor;}public int getCorePoolSize() {return corePoolSize;}public void setCorePoolSize(int corePoolSize) {this.corePoolSize = corePoolSize;}public int getMaxPoolSize() {return maxPoolSize;}public void setMaxPoolSize(int maxPoolSize) {this.maxPoolSize = maxPoolSize;}public long getKeepAliveTime() {return keepAliveTime;}public void setKeepAliveTime(long keepAliveTime) {this.keepAliveTime = keepAliveTime;}public int getQueueCapacity() {return queueCapacity;}public void setQueueCapacity(int queueCapacity) {this.queueCapacity = queueCapacity;}public TestRejectedExecutionHandler getTestRejectedExecutionHandler() {return testRejectedExecutionHandler;}public void setTestRejectedExecutionHandler(TestRejectedExecutionHandler testRejectedExecutionHandler) {this.testRejectedExecutionHandler = testRejectedExecutionHandler;}
}

步骤7：创建IThreadPoolMonitorService接口

IThreadPoolMonitorService接口已创建。

package com.otv.monitor.srv;import java.util.concurrent.ThreadPoolExecutor;public interface IThreadPoolMonitorService extends Runnable {public void monitorThreadPool();public ThreadPoolExecutor getExecutor();public void setExecutor(ThreadPoolExecutor executor);}

步骤8：创建ThreadPoolMonitorService类

ThreadPoolMonitorService类是通过实现IThreadPoolMonitorService接口创建的。 此类监视创建的线程池。

package com.otv.monitor.srv;import java.util.concurrent.ThreadPoolExecutor;
import org.apache.log4j.Logger;/*** @author onlinetechvision.com* @since 17 Oct 2011* @version 1.0.0**/
public class ThreadPoolMonitorService implements IThreadPoolMonitorService {private static Logger log = Logger.getLogger(ThreadPoolMonitorService.class);ThreadPoolExecutor executor;private long monitoringPeriod; public void run() {try {while (true){monitorThreadPool();Thread.sleep(monitoringPeriod*1000);}} catch (Exception e) {log.error(e.getMessage());}}public void monitorThreadPool() {StringBuffer strBuff = new StringBuffer();strBuff.append("CurrentPoolSize : ").append(executor.getPoolSize());strBuff.append(" - CorePoolSize : ").append(executor.getCorePoolSize());strBuff.append(" - MaximumPoolSize : ").append(executor.getMaximumPoolSize());strBuff.append(" - ActiveTaskCount : ").append(executor.getActiveCount());strBuff.append(" - CompletedTaskCount : ").append(executor.getCompletedTaskCount());strBuff.append(" - TotalTaskCount : ").append(executor.getTaskCount());strBuff.append(" - isTerminated : ").append(executor.isTerminated());log.debug(strBuff.toString());}public ThreadPoolExecutor getExecutor() {return executor;}public void setExecutor(ThreadPoolExecutor executor) {this.executor = executor;}   public long getMonitoringPeriod() {return monitoringPeriod;}public void setMonitoringPeriod(long monitoringPeriod) {this.monitoringPeriod = monitoringPeriod;}
}

第9步：创建入门类

启动器类已创建。

package com.otv.start;import java.util.concurrent.ThreadPoolExecutor;import org.apache.log4j.Logger;import com.otv.handler.TestRejectedExecutionHandler;
import com.otv.monitor.srv.IThreadPoolMonitorService;
import com.otv.monitor.srv.ThreadPoolMonitorService;
import com.otv.srv.ITestThreadPoolExecutorService;
import com.otv.srv.TestThreadPoolExecutorService;
import com.otv.task.TestTask;/*** @author onlinetechvision.com* @since 17 Oct 2011* @version 1.0.0**/
public class Starter {private static Logger log = Logger.getLogger(TestRejectedExecutionHandler.class);IThreadPoolMonitorService threadPoolMonitorService;ITestThreadPoolExecutorService testThreadPoolExecutorService;public void start() {// A new thread pool is created...ThreadPoolExecutor executor = testThreadPoolExecutorService.createNewThreadPool();executor.allowCoreThreadTimeOut(true);// Created executor is set to ThreadPoolMonitorService...threadPoolMonitorService.setExecutor(executor);// ThreadPoolMonitorService is started...Thread monitor = new Thread(threadPoolMonitorService);monitor.start();// New tasks are executed...for(int i=1;i<10;i++) {executor.execute(new TestTask("Task"+i));}try {Thread.sleep(40000);} catch (Exception e)   {log.error(e.getMessage());}for(int i=10;i<19;i++) {executor.execute(new TestTask("Task"+i));}// executor is shutdown...executor.shutdown();}   public IThreadPoolMonitorService getThreadPoolMonitorService() {return threadPoolMonitorService;}public void setThreadPoolMonitorService(IThreadPoolMonitorService threadPoolMonitorService) {this.threadPoolMonitorService = threadPoolMonitorService;}public ITestThreadPoolExecutorService getTestThreadPoolExecutorService() {return testThreadPoolExecutorService;}public void setTestThreadPoolExecutorService(ITestThreadPoolExecutorService testThreadPoolExecutorService) {this.testThreadPoolExecutorService = testThreadPoolExecutorService;}
}

步骤10：创建应用程序类

应用程序类已创建。 此类运行应用程序。

package com.otv.start;import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;/*** @author onlinetechvision.com* @since 17 Oct 2011* @version 1.0.0**/
public class Application {public static void main(String[] args) {ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");Starter starter = (Starter) context.getBean("Starter");starter.start();}}

步骤11：创建applicationContext.xml

applicationContext.xml已创建。

<beans xmlns="http://www.springframework.org/schema/beans"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://www.springframework.org/schema/beanshttp://www.springframework.org/schema/beans/spring-beans-3.0.xsd"><!-- Beans Declaration --><bean id="TestTask" class="com.otv.task.TestTask"></bean><bean id="ThreadPoolMonitorService" class="com.otv.monitor.srv.ThreadPoolMonitorService"><property name="monitoringPeriod"  value="5" /></bean><bean id="TestRejectedExecutionHandler" class="com.otv.handler.TestRejectedExecutionHandler"></bean><bean id="TestThreadPoolExecutorService" class="com.otv.srv.TestThreadPoolExecutorService"><property name="corePoolSize"  value="1" /><property name="maxPoolSize"   value="3" /><property name="keepAliveTime" value="10" /><property name="queueCapacity" value="3" /><property name="testRejectedExecutionHandler" ref="TestRejectedExecutionHandler" /></bean><bean id="Starter" class="com.otv.start.Starter"><property name="threadPoolMonitorService" ref="ThreadPoolMonitorService" /><property name="testThreadPoolExecutorService" ref="TestThreadPoolExecutorService" /></bean>
</beans>

步骤12：创建线程池的替代方法

Spring提供的ThreadPoolTask​​Executor类也可以用于创建线程池。

<bean id="threadPoolTaskExecutor" class="org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor"><property name="corePoolSize"  value="1" /><property name="maxPoolSize"   value="3" /><property name="queueCapacity" value="3" />
</bean><bean id="testTaskExecutor" class="TestTaskExecutor"><constructor-arg ref="threadPoolTaskExecutor" />
</bean>

步骤13：建立专案

生成OTV_Spring_ThreadPool项目后，将创建OTV_Spring_ThreadPool-0.0.1-SNAPSHOT.jar 。

步骤14：运行项目

运行创建的OTV_Spring_ThreadPool-0.0.1-SNAPSHOT.jar文件后，将在下面显示输出日志：

18.10.2011 20:08:48 DEBUG (TestRejectedExecutionHandler.java:19) - Task7 : has been rejected
18.10.2011 20:08:48 DEBUG (TestRejectedExecutionHandler.java:19) - Task8 : has been rejected
18.10.2011 20:08:48 DEBUG (TestRejectedExecutionHandler.java:19) - Task9 : has been rejected
18.10.2011 20:08:48 DEBUG (TestTask.java:25) - Task1 : is started.
18.10.2011 20:08:48 DEBUG (TestTask.java:25) - Task6 : is started.
18.10.2011 20:08:48 DEBUG (ThreadPoolMonitorService.java:39) - CurrentPoolSize : 3 - CorePoolSize : 1 - MaximumPoolSize : 3 - ActiveTaskCount : 2 - CompletedTaskCount : 0 - TotalTaskCount : 5 - isTerminated : false
18.10.2011 20:08:48 DEBUG (TestTask.java:25) - Task5 : is started.
18.10.2011 20:08:53 DEBUG (ThreadPoolMonitorService.java:39) - CurrentPoolSize : 3 - CorePoolSize : 1 - MaximumPoolSize : 3 - ActiveTaskCount : 3 - CompletedTaskCount : 0 - TotalTaskCount : 6 - isTerminated : false
18.10.2011 20:08:58 DEBUG (TestTask.java:27) - Task6 : is completed.
18.10.2011 20:08:58 DEBUG (TestTask.java:27) - Task1 : is completed.
18.10.2011 20:08:58 DEBUG (TestTask.java:25) - Task3 : is started.
18.10.2011 20:08:58 DEBUG (TestTask.java:25) - Task2 : is started.
18.10.2011 20:08:58 DEBUG (ThreadPoolMonitorService.java:39) - CurrentPoolSize : 3 - CorePoolSize : 1 - MaximumPoolSize : 3 - ActiveTaskCount : 3 - CompletedTaskCount : 2 - TotalTaskCount : 6 - isTerminated : false
18.10.2011 20:08:58 DEBUG (TestTask.java:27) - Task5 : is completed.
18.10.2011 20:08:58 DEBUG (TestTask.java:25) - Task4 : is started.
18.10.2011 20:09:03 DEBUG (ThreadPoolMonitorService.java:39) - CurrentPoolSize : 3 - CorePoolSize : 1 - MaximumPoolSize : 3 - ActiveTaskCount : 3 - CompletedTaskCount : 3 - TotalTaskCount : 6 - isTerminated : false
18.10.2011 20:09:08 DEBUG (TestTask.java:27) - Task2 : is completed.
18.10.2011 20:09:08 DEBUG (TestTask.java:27) - Task3 : is completed.
18.10.2011 20:09:08 DEBUG (TestTask.java:27) - Task4 : is completed.
18.10.2011 20:09:08 DEBUG (ThreadPoolMonitorService.java:39) - CurrentPoolSize : 3 - CorePoolSize : 1 - MaximumPoolSize : 3 - ActiveTaskCount : 0 - CompletedTaskCount : 6 - TotalTaskCount : 6 - isTerminated : false
18.10.2011 20:09:13 DEBUG (ThreadPoolMonitorService.java:39) - CurrentPoolSize : 3 - CorePoolSize : 1 - MaximumPoolSize : 3 - ActiveTaskCount : 0 - CompletedTaskCount : 6 - TotalTaskCount : 6 - isTerminated : false
18.10.2011 20:09:18 DEBUG (ThreadPoolMonitorService.java:39) - CurrentPoolSize : 0 - CorePoolSize : 1 - MaximumPoolSize : 3 - ActiveTaskCount : 0 - CompletedTaskCount : 6 - TotalTaskCount : 6 - isTerminated : false
18.10.2011 20:09:23 DEBUG (ThreadPoolMonitorService.java:39) - CurrentPoolSize : 0 - CorePoolSize : 1 - MaximumPoolSize : 3 - ActiveTaskCount : 0 - CompletedTaskCount : 6 - TotalTaskCount : 6 - isTerminated : false
18.10.2011 20:09:28 DEBUG (TestTask.java:25) - Task10 : is started.
18.10.2011 20:09:28 DEBUG (TestRejectedExecutionHandler.java:19) - Task16 : has been rejected
18.10.2011 20:09:28 DEBUG (TestRejectedExecutionHandler.java:19) - Task17 : has been rejected
18.10.2011 20:09:28 DEBUG (TestRejectedExecutionHandler.java:19) - Task18 : has been rejected
18.10.2011 20:09:28 DEBUG (TestTask.java:25) - Task14 : is started.
18.10.2011 20:09:28 DEBUG (TestTask.java:25) - Task15 : is started.
18.10.2011 20:09:28 DEBUG (ThreadPoolMonitorService.java:39) - CurrentPoolSize : 3 - CorePoolSize : 1 - MaximumPoolSize : 3 - ActiveTaskCount : 3 - CompletedTaskCount : 6 - TotalTaskCount : 12 - isTerminated : false
18.10.2011 20:09:33 DEBUG (ThreadPoolMonitorService.java:39) - CurrentPoolSize : 3 - CorePoolSize : 1 - MaximumPoolSize : 3 - ActiveTaskCount : 3 - CompletedTaskCount : 6 - TotalTaskCount : 12 - isTerminated : false
18.10.2011 20:09:38 DEBUG (TestTask.java:27) - Task10 : is completed.
18.10.2011 20:09:38 DEBUG (TestTask.java:25) - Task11 : is started.
18.10.2011 20:09:38 DEBUG (TestTask.java:27) - Task14 : is completed.
18.10.2011 20:09:38 DEBUG (TestTask.java:27) - Task15 : is completed.
18.10.2011 20:09:38 DEBUG (TestTask.java:25) - Task12 : is started.
18.10.2011 20:09:38 DEBUG (TestTask.java:25) - Task13 : is started.
18.10.2011 20:09:38 DEBUG (ThreadPoolMonitorService.java:39) - CurrentPoolSize : 3 - CorePoolSize : 1 - MaximumPoolSize : 3 - ActiveTaskCount : 3 - CompletedTaskCount : 9 - TotalTaskCount : 12 - isTerminated : false
18.10.2011 20:09:43 DEBUG (ThreadPoolMonitorService.java:39) - CurrentPoolSize : 3 - CorePoolSize : 1 - MaximumPoolSize : 3 - ActiveTaskCount : 3 - CompletedTaskCount : 9 - TotalTaskCount : 12 - isTerminated : false
18.10.2011 20:09:48 DEBUG (TestTask.java:27) - Task11 : is completed.
18.10.2011 20:09:48 DEBUG (TestTask.java:27) - Task13 : is completed.
18.10.2011 20:09:48 DEBUG (TestTask.java:27) - Task12 : is completed.
18.10.2011 20:09:48 DEBUG (ThreadPoolMonitorService.java:39) - CurrentPoolSize : 0 - CorePoolSize : 1 - MaximumPoolSize : 3 - ActiveTaskCount : 0 - CompletedTaskCount : 12 - TotalTaskCount : 12 - isTerminated : true
18.10.2011 20:09:53 DEBUG (ThreadPoolMonitorService.java:39) - CurrentPoolSize : 0 - CorePoolSize : 1 - MaximumPoolSize : 3 - ActiveTaskCount : 0 - CompletedTaskCount : 12 - TotalTaskCount : 12 - isTerminated : true

步骤15：下载

OTV_Spring_ThreadPool

参考： 如何使用我们JCG合作伙伴提供的 Spring开发和监视线程池服务   在线技术愿景博客上的Eren Avsarogullari。