package org.time; 
 
import java.util.TimerTask; 
 
public class MainTask extends TimerTask{ 
 
 @Override 
 public void run() { 
  System.out.println("检测用户是否掉线"); 
 } 
 
} 

<?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" 
 xsi:schemaLocation="http://www.springframework.org/schema/beans 
 http://www.springframework.org/schema/beans/spring-beans-3.0.xsd"> 
  
 <bean id="mainTask" class="org.time.MainTask"></bean> 
 
 <!-- 注册定时器信息 --> 
 <bean id="springTask" class="org.springframework.scheduling.timer.ScheduledTimerTask"> 
  <!-- 延迟1秒执行首次任务 --> 
  <property name="delay" value="1000"></property> 
  <!-- 每隔2秒执行一次任务 --> 
  <property name="period" value="2000"></property> 
  <!-- 具体执行的任务 --> 
  <property name="timerTask" ref="mainTask"></property> 
 </bean> 
 <!-- 配置任务调度器工厂 --> 
 <bean id="timerFactory" class="org.springframework.scheduling.timer.TimerFactoryBean"> 
  <property name="scheduledTimerTasks"> 
   <list> 
    <ref bean="springTask"/> 
   </list> 
  </property> 
 </bean> 
</beans> 

<?xml version="1.0" encoding="UTF-8"?> 
<web-app version="2.5" 
 xmlns="http://java.sun.com/xml/ns/javaee" 
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
 xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
 http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"> 
 <display-name></display-name> 
 <welcome-file-list> 
 <welcome-file>index.jsp</welcome-file> 
 </welcome-file-list> 
 <listener> 
 <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> 
 </listener> 
 <context-param> 
 <param-name>contextConfigLocation</param-name> 
 <param-value>/WEB-INF/applicationContext.xml</param-value> 
 </context-param> 
</web-app>

package org.time; 
 
import org.springframework.scheduling.annotation.Scheduled; 
import org.springframework.stereotype.Component; 
 
@Component 
public class MainTask01{ 
 @Scheduled(cron = "0/3 * * * * ?") 
 public void run() { 
  System.out.println("推送消息来了"); 
 } 
 
} 

<?xml version="1.0" encoding="UTF-8"?> 
<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
 xmlns:tx="http://www.springframework.org/schema/tx" 
 xmlns:aop="http://www.springframework.org/schema/aop" 
 xmlns:context="http://www.springframework.org/schema/context" 
 xmlns:task="http://www.springframework.org/schema/task" 
 xmlns="http://www.springframework.org/schema/beans" 
 xsi:schemaLocation="http://www.springframework.org/schema/beans 
  http://www.springframework.org/schema/beans/spring-beans.xsd 
  http://www.springframework.org/schema/tx 
  http://www.springframework.org/schema/tx/spring-tx.xsd 
  http://www.springframework.org/schema/aop 
  http://www.springframework.org/schema/aop/spring-aop.xsd 
  http://www.springframework.org/schema/context 
  http://www.springframework.org/schema/context/spring-context.xsd 
  http://www.springframework.org/schema/task 
  http://www.springframework.org/schema/task/spring-task.xsd"> 
 
 <context:annotation-config /> 
 <!-- spring扫描注解的配置 --> 
 <context:component-scan base-package="org.time" /> 
  
 <task:annotation-driven scheduler="qbScheduler" mode="proxy"/> 
 <task:scheduler id="qbScheduler" pool-size="10"/> 
 
</beans>

xmlns:task="http://www.springframework.org/schema/task" 
http://www.springframework.org/schema/task 
http://www.springframework.org/schema/task/spring-task.xsd