JavaWeb三种常用的定时任务简单示例

一、JavaWeb项目中java自带的定时器Timer

(1)、代码如下：package com.sundy.task;import java.util.Timer;import java.util.TimerTask;import javax.servlet.ServletContextEvent;import javax.servlet.ServletContextListener;public class MyTimerTask implements ServletContextListener{private Timer timer;@Overridepublic void contextDestroyed(ServletContextEvent arg0) {if(timer!=null) timer.cancel();}@Overridepublic void contextInitialized(ServletContextEvent arg0) {timer = new Timer();timer.schedule(new TimerTask() {@Overridepublic void run() {work();}}, 1000, 15*1000);// 一秒后执行，间隔十五秒执行一次。}private void work() {System.out.println("定时任务....");}}(2)、需要在web.xml中增加<listener><listener-class>com.sundy.task.MyTimerTask</listener-class></listener>

二、JavaWeb项目中Spring自带的定时任务的使用简介

1)、非注解的开发1.1、普通的JavaBeanpackage com.sundy.task;public class MyTask {public void task(){System.out.println("定时任务...");}}1.2、在applicationContext.xml中的配置如下。<?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:task="http://www.springframework.org/schema/task"xmlns:context="http://www.springframework.org/schema/context"xsi:schemaLocation="http://www.springframework.org/schema/beanshttp://www.springframework.org/schema/beans/spring-beans.xsdhttp://www.springframework.org/schema/contexthttp://www.springframework.org/schema/context/spring-context.xsdhttp://www.springframework.org/schema/taskhttp://www.springframework.org/schema/task/spring-task-4.2.xsd"><bean id="myTask" class="com.sundy.task.MyTask"></bean> <task:scheduled-tasks> <!-- cron的表达式可参考《http://blog.csdn.net/evilcry2012/article/details/51991791》 --><task:scheduled ref="myTask" method="task" cron="*/5 * * * * ?"/> <!-- 每隔五秒执行一次com.sundy.task.MyTask类中的task()方法 --></task:scheduled-tasks> </beans>1.3、在web中记得增加：<!-- 加载spring容器 --><context-param><param-name>contextConfigLocation</param-name><param-value>classpath:applicationContext.xml</param-value></context-param><listener><listener-class>org.springframework.web.context.ContextLoaderListener</listener-class></listener>(2)、注解的开发2.1、普通的JavaBeanpackage com.sundy.task;import org.springframework.scheduling.annotation.Scheduled;import org.springframework.stereotype.Component;@Componentpublic class MyTask {@Scheduled(cron="*/5 * * * * ?")public void task1(){System.out.println("定时任务...");}}2.2、在applicationContext.xml中的配置<context:component-scan base-package="com.sundy.task"/><!-- 配置任务线性池 -->      <task:executor id="executor" pool-size="10" />      <task:scheduler id="scheduler" pool-size="10" />  <task:annotation-driven scheduler="scheduler" executor="executor" proxy-target-class="true"/>

三、定时任务quartz的简单使用

(1)、官网下载地址：http://www.quartz-scheduler.org/downloads/任务调度开源框架Quartz动态添加、修改和删除定时任务 地址：http://blog.csdn.net/luo201227/article/details/37511137(2)、非注解的简单示例(参考：http://veiking.iteye.com/blog/2371511)1.1、普通的JavaBeanpackage com.sundy.quartz;public class SimpleJob {public void runTask() {System.out.println("runTask()....");}}1.2、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:task="http://www.springframework.org/schema/task"xmlns:context="http://www.springframework.org/schema/context"xsi:schemaLocation="http://www.springframework.org/schema/beanshttp://www.springframework.org/schema/beans/spring-beans.xsdhttp://www.springframework.org/schema/contexthttp://www.springframework.org/schema/context/spring-context.xsdhttp://www.springframework.org/schema/taskhttp://www.springframework.org/schema/task/spring-task-4.2.xsd"><bean id="simpleJob" class="com.sundy.quartz.SimpleJob"></bean>   <bean id="simpleJobDetail" class="org.springframework.scheduling.quartz.MethodInvokingJobDetailFactoryBean"><property name="targetObject" ref="simpleJob"/>    <property name="targetMethod" value="runTask"/>    <property name="concurrent" value="false"/>    <!-- concurrent : false表示等上一个任务执行完后再开启新的任务 -->    </bean>   <!-- 配置任务调度的时间/周期、延时 -->    <bean id="simpleJobDetailTrigger" class="org.springframework.scheduling.quartz.CronTriggerFactoryBean">    <property name="jobDetail" ref="simpleJobDetail"/>  <property name="cronExpression" value="*/10 * * * * ?"/>    <property name="startDelay" value="3000"/>  </bean> <!-- 配置任务调度中心 -->  <bean id="schedulerFactoryBean"  class="org.springframework.scheduling.quartz.SchedulerFactoryBean">    <property name="triggers">    <list>     <ref bean="simpleJobDetailTrigger"/>  </list>  </property>    </bean>  </beans>