paulwong

FutureTask and ThreadPoolExecutor

用ThreadPoolExecutor的时候，又想知道被执行的任务的执行情况，这时就可以用FutureTask。

ThreadPoolTask
package com.paul.threadPool;

import java.io.Serializable;
import java.util.concurrent.Callable;

public class ThreadPoolTask implements Callable<String>, Serializable {

    private static final long serialVersionUID = 0;
    
    // 保存任务所需要的数据
    private Object threadPoolTaskData;

    private static int consumeTaskSleepTime = 2000;

    public ThreadPoolTask(Object tasks) {
        this.threadPoolTaskData = tasks;
    }

    public synchronized String call() throws Exception {
        // 处理一个任务，这里的处理方式太简单了，仅仅是一个打印语句
        System.out.println("开始执行任务：" + threadPoolTaskData);
        String result = "";
        // //便于观察，等待一段时间
        try {
//            long r = 5/0;
            for ( int  i= 0 ; i< 100000000 ; i++){   
                
            } 
            result = "OK";
        } catch (Exception e) {
            e.printStackTrace();
            result = "ERROR";
        }
        threadPoolTaskData = null;
        return result;
    }
}

模拟客户端提交的线程
package com.paul.threadPool;

import java.util.concurrent.ExecutionException;
import java.util.concurrent.FutureTask;

import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;

public class StartTaskThread implements Runnable{

private ThreadPoolTaskExecutor threadPoolTaskExecutor;
private int i;

public StartTaskThread(ThreadPoolTaskExecutor threadPoolTaskExecutor,int i)
{
this.threadPoolTaskExecutor = threadPoolTaskExecutor;
this.i = i;
}

@Override
public synchronized void run() {
String task = "task@ " + i;
System.out.println("创建任务并提交到线程池中：" + task);
FutureTask<String> futureTask = new FutureTask<String>(
new ThreadPoolTask(task));
threadPoolTaskExecutor.execute(futureTask);
// 在这里可以做别的任何事情
 String result = null;
try {
// 取得结果，同时设置超时执行时间为0.1秒。同样可以用future.get()，不设置执行超时时间取得结果
 result = futureTask.get();

} catch (InterruptedException e) {
futureTask.cancel(true);
} catch (ExecutionException e) {
futureTask.cancel(true);
} catch (Exception e) {
futureTask.cancel(true);
// 超时后，进行相应处理
 } finally {
 System.out.println("task@" + i + ":result=" + result);
}

}


SPRING配置文件
<?xml version="1.0" encoding="UTF-8" ?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:p="http://www.springframework.org/schema/p"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsd">



<!-- 配置数据源 -->
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"
destroy-method="close" p:driverClassName="com.mysql.jdbc.Driver"
p:url="jdbc:mysql://localhost:3306/mb_main?useUnicode=true&amp;characterEncoding=UTF-8&amp;useServerPrepStmts=true" p:username="root" p:password="1234" />

<!-- 配置Jdbc模板 -->
<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate"
p:dataSource-ref="dataSource" />

<!-- 事务管理器 -->
<bean id="transactionManager"
class="org.springframework.jdbc.datasource.DataSourceTransactionManager"
p:dataSource-ref="dataSource" />

<tx:advice id="jdbcTxAdvice" transaction-manager="transactionManager">
<tx:attributes>
<tx:method name="*" />
</tx:attributes>
</tx:advice>

<!-- 使用aop/tx命名空间配置事务管理,这里对service包下的服务类方法提供事务 -->
<aop:config>
<aop:pointcut id="jdbcServiceMethod" expression="within(com.baobaotao.service..*)" />
<aop:advisor pointcut-ref="jdbcServiceMethod" advice-ref="jdbcTxAdvice" />
</aop:config>

<!-- 配置dao
<bean id="loginLogDao" class="com.baobaotao.dao.LoginLogDao"
p:jdbcTemplate-ref="jdbcTemplate" />
<bean id="userDao" class="com.baobaotao.dao.UserDao"
p:jdbcTemplate-ref="jdbcTemplate" />


<bean id="userService" class="com.baobaotao.service.UserService"
p:userDao-ref="userDao" p:loginLogDao-ref="loginLogDao" />
-->

<bean id="threadPoolTaskExecutor" class="org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor">

<!-- 核心线程数，默认为1 -->
<property name="corePoolSize" value="10" />

<!-- 最大线程数，默认为Integer.MAX_VALUE -->
<property name="maxPoolSize" value="50" />

<!-- 队列最大长度，一般需要设置值>=notifyScheduledMainExecutor.maxNum；默认为Integer.MAX_VALUE
<property name="queueCapacity" value="1000" />
-->

<!-- 线程池维护线程所允许的空闲时间，默认为60s -->
<property name="keepAliveSeconds" value="300" />

<!-- 线程池对拒绝任务（无线程可用）的处理策略，目前只支持AbortPolicy、CallerRunsPolicy；默认为后者 -->
<property name="rejectedExecutionHandler">
<!-- AbortPolicy:直接抛出java.util.concurrent.RejectedExecutionException异常 -->
<!-- CallerRunsPolicy:主线程直接执行该任务，执行完之后尝试添加下一个任务到线程池中，可以有效降低向线程池内添加任务的速度 -->
<!-- DiscardOldestPolicy:抛弃旧的任务、暂不支持；会导致被丢弃的任务无法再次被执行 -->
<!-- DiscardPolicy:抛弃当前任务、暂不支持；会导致被丢弃的任务无法再次被执行 -->
<bean class="java.util.concurrent.ThreadPoolExecutor$CallerRunsPolicy" />
</property>

</bean>


</beans>


测试类
package com.paul.threadPool;

import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;

import org.junit.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.AbstractJUnit4SpringContextTests;

@ContextConfiguration
public class TestThreadPool extends AbstractJUnit4SpringContextTests{

private static int produceTaskSleepTime = 10;

private static int produceTaskMaxNumber = 1000;

@Autowired
private ThreadPoolTaskExecutor threadPoolTaskExecutor;

public ThreadPoolTaskExecutor getThreadPoolTaskExecutor() {
return threadPoolTaskExecutor;
}

public void setThreadPoolTaskExecutor(
ThreadPoolTaskExecutor threadPoolTaskExecutor) {
this.threadPoolTaskExecutor = threadPoolTaskExecutor;
}

@Test
public void testThreadPoolExecutor()
{
// 构造一个线程池
 final ThreadPoolExecutor threadPool = new ThreadPoolExecutor(2, 4, 600,
TimeUnit.SECONDS, new ArrayBlockingQueue<Runnable>(3),
new ThreadPoolExecutor.CallerRunsPolicy());

for (int i = 1; i <= produceTaskMaxNumber; i++) {

try {
Thread.sleep(produceTaskSleepTime);
} catch (InterruptedException e1) {
e1.printStackTrace();
}
new Thread(new StartTaskThread(threadPoolTaskExecutor,i)).start();
}

}

}

posted on 2011-12-07 15:48 paulwong 阅读(2693) 评论(1)  编辑  收藏 所属分类: 性能优化

Feedback

# re: FutureTask and ThreadPoolExecutor 2014-03-11 23:41 最代码

你好，我根据你的博客整理了分享了一份代码：http://www.zuidaima.com/share/1724478138158080.htm
并且发现你代码中有些纰漏都修改过来了。  回复  更多评论   



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