springmvc之定时器

一、通过注解方式实现定时器

1、工程结构

2、所需jar包

3、spring-config.xml，springmvc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:oxm="http://www.springframework.org/schema/oxm"
    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:task="http://www.springframework.org/schema/task"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
       http://www.springframework.org/schema/oxm
       http://www.springframework.org/schema/oxm/spring-oxm-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/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/task
       http://www.springframework.org/schema/task/spring-task-3.2.xsd">

    <!--  通知spring容器通过注解的方式装配bean -->
      <context:annotation-config />
    <!--  通知spring容器采用自动扫描机制查找注解的bean -->
      <context:component-scan base-package="com.*" /> 

      <task:annotation-driven /> <!-- 定时器开关-->  

     <!--  配置返回页面过滤 --> 
    <bean id="viewResolver" class="org.springframework.web.servlet.view.UrlBasedViewResolver">
        <property name="viewClass"
            value="org.springframework.web.servlet.view.JstlView" />
        <property name="prefix" value="/" />
        <property name="suffix" value=".jsp" />
    </bean>
</beans>

注：下面是需要引入头路径：

xmlns:task="http://www.springframework.org/schema/task"
xsi:schemaLocation="http://www.springframework.org/schema/task
http://www.springframework.org/schema/task/spring-task-3.2.xsd"

下面是定时器开关配置：

<task:annotation-driven/>

4、web.xml，加载springmvc配置

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://java.sun.com/xml/ns/javaee"
    xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
    http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
      <display-name>spring</display-name>    

    <!-- springmvc配置 -->
      <servlet>
        <servlet-name>springMVC</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>/WEB-INF/spring-config.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>springMVC</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
</web-app>

5、TimerController.java

package com.timer;

import java.text.SimpleDateFormat;
import java.util.Date;

import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;

@Component
public class TimerController { 

    /**
     * 每隔20秒执行一次
     */
    @Scheduled(fixedRate = 1000*20)
    public void print(){
        SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd H:m:s");
        System.out.println("timer : "+format.format(new Date()));
    }  

}

注：使用注解类前必须有@Component

二、通过配置xml文件实现定时器

1、spring-config.xml，springmvc配置

<?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:oxm="http://www.springframework.org/schema/oxm"
    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:task="http://www.springframework.org/schema/task"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
       http://www.springframework.org/schema/oxm
       http://www.springframework.org/schema/oxm/spring-oxm-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/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/task
       http://www.springframework.org/schema/task/spring-task-3.2.xsd">

    <!--  通知spring容器通过注解的方式装配bean -->
      <context:annotation-config />
    <!--  通知spring容器采用自动扫描机制查找注解的bean -->
      <context:component-scan base-package="com.*" /> 

      <task:annotation-driven /> <!-- 定时器开关-->

      <bean id="agentExcelTask" class="com.timer.TimerController1"/>
    <task:scheduled-tasks>
        <task:scheduled ref="agentExcelTask" method="print" cron="0/5 * * * * ?"/>
    </task:scheduled-tasks>  

    <!--  配置返回页面过滤 -->
    <bean id="viewResolver" class="org.springframework.web.servlet.view.UrlBasedViewResolver">
        <property name="viewClass"
            value="org.springframework.web.servlet.view.JstlView" />
        <property name="prefix" value="/" />
        <property name="suffix" value=".jsp" />
    </bean>
</beans>

注： 多了创建bean和时间配置，每隔5秒触发一次，代码如下：

<bean id="agentExcelTask" class="com.timer.TimerController1"/>
    <task:scheduled-tasks>
        <task:scheduled ref="agentExcelTask" method="print" cron="0/5 * * * * ?"/>
    </task:scheduled-tasks> 

注：method="print"指明触发的为TimerController1类中的print方法。

2、TimerController1.java

package com.timer;

import java.text.SimpleDateFormat;
import java.util.Date;

public class TimerController1 {

    public void print(){
        SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd H:m:s");
        System.out.println("timer1 : "+format.format(new Date()));
    } 

}

注：时间格式参考