spring的多线程配置

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本文介绍了如何在Spring框架中配置和使用多线程。通过查看executor.xml的配置，我们可以了解到具体的线程池设置，这有助于提高应用程序的并发性能。在实际运行中，这些配置将影响到日志打印的输出和线程调度策略。

API:

Method Summary

void afterPropertiesSet()
Calls initialize() after the container applied all property values.

protected edu.emory.mathcs.backport.java.util.concurrent.BlockingQueue createQueue(int queueCapacity)
Create the BlockingQueue to use for the ThreadPoolExecutor.

void destroy()
Calls shutdown when the BeanFactory destroys the task executor instance.

void execute(Runnable task)
Implementation of both the JSR-166 backport Executor interface and the Spring TaskExecutor interface, delegating to the ThreadPoolExecutor instance.

void execute(Runnable task, long startTimeout)
Execute the given task.

int getActiveCount()
Return the number of currently active threads.

int getCorePoolSize()
Return the ThreadPoolExecutor's core pool size.

int getKeepAliveSeconds()
Return the ThreadPoolExecutor's keep-alive seconds.

int getMaxPoolSize()
Return the ThreadPoolExecutor's maximum pool size.

int getPoolSize()
Return the current pool size.

edu.emory.mathcs.backport.java.util.concurrent.ThreadPoolExecutor getThreadPoolExecutor()
Return the underlying ThreadPoolExecutor for native access.

void initialize()
Creates the BlockingQueue and the ThreadPoolExecutor.

boolean prefersShortLivedTasks()
This task executor prefers short-lived work units.

void setAllowCoreThreadTimeOut(boolean allowCoreThreadTimeOut)
Specify whether to allow core threads to time out.

void setBeanName(String name)
Set the name of the bean in the bean factory that created this bean.

void setCorePoolSize(int corePoolSize)
Set the ThreadPoolExecutor's core pool size.

void setKeepAliveSeconds(int keepAliveSeconds)
Set the ThreadPoolExecutor's keep-alive seconds.

void setMaxPoolSize(int maxPoolSize)
Set the ThreadPoolExecutor's maximum pool size.

void setQueueCapacity(int queueCapacity)
Set the capacity for the ThreadPoolExecutor's BlockingQueue.

void setRejectedExecutionHandler(edu.emory.mathcs.backport.java.util.concurrent.RejectedExecutionHandler rejectedExecutionHandler)
Set the RejectedExecutionHandler to use for the ThreadPoolExecutor.

void setThreadFactory(edu.emory.mathcs.backport.java.util.concurrent.ThreadFactory threadFactory)
Set the ThreadFactory to use for the ThreadPoolExecutor's thread pool.

void setThreadNamePrefix(String threadNamePrefix)
Specify the prefix to use for the names of newly created threads.

void setWaitForTasksToCompleteOnShutdown(boolean waitForJobsToCompleteOnShutdown)
Set whether to wait for scheduled tasks to complete on shutdown.

void shutdown()
Perform a shutdown on the ThreadPoolExecutor.

<T> Future<T>

submit(Callable<T> task)
Submit a Callable task for execution, receiving a Future representing that task.

Future<?> submit(Runnable task)
Submit a Runnable task for execution, receiving a Future representing that task.

executor.xml的配置如下：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:task="http://www.springframework.org/schema/task" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns:context="http://www.springframework.org/schema/context"
	xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
	xmlns:jee="http://www.springframework.org/schema/jee"
	xsi:schemaLocation="http://www.springframework.org/schema/beans   
       http://www.springframework.org/schema/beans/spring-beans-3.0.xsd    
       http://www.springframework.org/schema/tx   
       http://www.springframework.org/schema/tx/spring-tx-3.0.xsd    
       http://www.springframework.org/schema/aop   
       http://www.springframework.org/schema/aop/spring-aop-3.0.xsd    
       http://www.springframework.org/schema/context   
       http://www.springframework.org/schema/context/spring-context-3.0.xsd  
       http://www.springframework.org/schema/task  
       http://www.springframework.org/schema/task/spring-task-3.0.xsd  
       http://www.springframework.org/schema/jee       
       http://www.springframework.org/schema/jee/spring-jee-3.0.xsd">

	<!-- 如上添加 相关task标签 /|\ -->


	<!-- <dependency>
		<groupId>org.springframework</groupId>
		<artifactId>spring-context-support</artifactId>
		<version>4.3.10.RELEASE</version>
	</dependency> -->

	<!-- spring线程池 -->
	<bean id="taskExecutor"
		class="org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor">
		<!-- 线程池维护线程的最少数量 -->
		<property name="corePoolSize" value="5" />
		<!-- 线程池维护线程所允许的空闲时间，默认为60s -->
		<property name="keepAliveSeconds" value="200" />
		<!-- 线程池维护线程的最大数量 -->
		<property name="maxPoolSize" value="20" />
		<!-- 缓存队列最大长度 -->
		<property name="queueCapacity" value="20" />
		<!-- 对拒绝task的处理策略 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>
		<property name="waitForTasksToCompleteOnShutdown" value="true" />
	</bean>

</beans>

测试类ExecutorTest1.java的代码：

package com.soecode.lyf.web.test;

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

public class ExecutorTest1 {


	@Test
	public void test() {

		try {

			ApplicationContext context1  = new ClassPathXmlApplicationContext("executor.xml"); 
			ThreadPoolTaskExecutor taskExecutor = (ThreadPoolTaskExecutor)context1.getBean("taskExecutor");
			for(int i=0;i<10;i++){
				taskExecutor.execute(new Runnable(){
					@Override
					public void run() {
						System.out.println(Thread.currentThread());
					}
				});
			}
			System.out.println("main方法结束");
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

}

打印的日志：

[org.springframework.context.support.ClassPathXmlApplicationContext] - Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@55816088: startup date [Thu Feb 08 15:16:54 CST 2018]; root of context hierarchy
  [org.springframework.beans.factory.xml.XmlBeanDefinitionReader] - Loading XML bean definitions from class path resource [executor.xml]
  [org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor] - Initializing ExecutorService  'taskExecutor'
  Thread[taskExecutor-1,5,main]
Thread[taskExecutor-3,5,main]
Thread[taskExecutor-4,5,main]
Thread[taskExecutor-2,5,main]
main方法结束
Thread[taskExecutor-1,5,main]
Thread[taskExecutor-1,5,main]
Thread[taskExecutor-1,5,main]
Thread[taskExecutor-1,5,main]
Thread[taskExecutor-2,5,main]
Thread[taskExecutor-5,5,main]