缓存初解（五）---SpringMVC基于注解的缓存配置--web应用实例

之前为大家介绍了如何使用spring注解来进行缓存配置 （EHCache 和 OSCache）的简单的例子，详见

Spring基于注解的缓存配置--EHCache AND OSCache

现在介绍一下如何在基于注解springMVC的web应用中使用注解缓存，其实很简单，就是将springMVC配置文件与缓存注解文件一起声明到context中就OK了。

下面我就来构建一个基于spring注解小型的web应用,这里我使用EHCache来作为缓存方案

jar依赖：

ehcache-core-1.7.2.jar
jakarta-oro-2.0.8.jar
slf4j-api-1.5.8.jar
slf4j-jdk14-1.5.8.jar 
cglib-nodep-2.1_3.jar
commons-logging.jar
log4j-1.2.15.jar
spring-modules-cache.jar
spring.jar 
jstl.jar

standard.jar

接着我们来编写web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	id="WebApp_ID" version="2.4"
	xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
	<display-name>SpringCacheWeb</display-name>

	<!-- 由spring加载log4j -->
	<context-param>
		<param-name>log4jConfigLocation</param-name>
		<param-value>classpath:log4j.properties</param-value>
	</context-param>

	<!-- 声明spring配置文件 -->
	<context-param>
		<param-name>contextConfigLocation</param-name>
		<param-value>
			/WEB-INF/spring-servlet.xml
		</param-value>
	</context-param>

	<!-- 使用UTF-8编码 -->
	<filter>
		<filter-name>Set Character Encoding</filter-name>
		<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
		<init-param>
			<param-name>encoding</param-name>
			<param-value>UTF-8</param-value>
		</init-param>
	</filter>
	<filter-mapping>
		<filter-name>Set Character Encoding</filter-name>
		<url-pattern>*.do</url-pattern>
	</filter-mapping>

	<!-- 负责初始化log4j-->
	<listener>
		<listener-class>org.springframework.web.util.Log4jConfigListener</listener-class>
	</listener>

	<!-- 负责初始化spring上下文-->
	<listener>
		<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
	</listener>

	<!-- springMVC控制器-->
	<servlet>
		<servlet-name>spring</servlet-name>
		<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
		<load-on-startup>1</load-on-startup>
	</servlet>

	<servlet-mapping>
		<servlet-name>spring</servlet-name>
		<url-pattern>*.do</url-pattern>
	</servlet-mapping>

	<session-config>
		<session-timeout>10</session-timeout>
	</session-config>

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

接着我们来编写spring-servlet.xml

<?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:context="http://www.springframework.org/schema/context"
	xmlns:ehcache="http://www.springmodules.org/schema/ehcache"
	xsi:schemaLocation="
			http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
			http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd
			http://www.springmodules.org/schema/ehcache http://www.springmodules.org/schema/cache/springmodules-ehcache.xsd"
			default-lazy-init="true">

	<!--启用注解   定义组件查找规则 -->
	<context:component-scan base-package="com.netqin">
		<context:include-filter type="annotation"
			expression="org.springframework.stereotype.Controller" />
		<context:include-filter type="annotation"
			expression="org.springframework.stereotype.Service" />
		<context:include-filter type="annotation"
			expression="org.springframework.stereotype.Repository" />
	</context:component-scan>

	<!-- 视图查找器 -->
	<bean id="viewResolver"
		class="org.springframework.web.servlet.view.InternalResourceViewResolver">
		<property name="viewClass"
			value="org.springframework.web.servlet.view.JstlView">
		</property>
		<property name="prefix" value="/WEB-INF/jsp/"></property>
		<property name="suffix" value=".jsp"></property>
	</bean>

	<!-- 加载ehcache缓存配置文件 

	说明：在这里我遇到了这样一个问题，当使用@Service等注解的方式将类声明到配置文件中时，
	就需要将缓存配置import到主配置文件中，否则缓存会不起作用
	如果是通过<bean>声明到配置文件中时，
	则只需要在web.xml的contextConfigLocation中加入applicationContext-ehcache.xml即可，
	不过还是推荐使用如下方式吧，因为这样不会有任何问题
	-->
	<import resource="classpath:applicationContext-ehcache.xml"/>
</beans>

ok，我们接着编写applicationContext-ehcache.xml，还记得之前介绍的基于命名空间的配置吗，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:ehcache="http://www.springmodules.org/schema/ehcache"
	xsi:schemaLocation="
			http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
			http://www.springmodules.org/schema/ehcache http://www.springmodules.org/schema/cache/springmodules-ehcache.xsd">

	<ehcache:config configLocation="classpath:ehcache.xml"
		id="cacheProvider" />
	<ehcache:annotations providerId="cacheProvider">
		<ehcache:caching cacheName="testCache" id="testCaching" />
		<ehcache:flushing cacheNames="testCache" id="testFlushing" />
	</ehcache:annotations>

</beans>

ehcache.xml如下

<?xml version="1.0" encoding="UTF-8"?>
<ehcache xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:noNamespaceSchemaLocation="ehcache.xsd" updateCheck="true"
	monitoring="autodetect">
	<diskStore path="java.io.tmpdir"/>
    <defaultCache
            maxElementsInMemory="10000"
            eternal="false"
            timeToIdleSeconds="120"
            timeToLiveSeconds="120"
            overflowToDisk="true"
            maxElementsOnDisk="10000000"
            diskPersistent="false"
            diskExpiryThreadIntervalSeconds="120"
            memoryStoreEvictionPolicy="LRU"
            />
	 <cache name="testCache"
           maxElementsInMemory="10000"
           maxElementsOnDisk="1000"
           eternal="false"
           overflowToDisk="true"
           diskSpoolBufferSizeMB="20"
           timeToIdleSeconds="300"
           timeToLiveSeconds="600"
           memoryStoreEvictionPolicy="LFU"
            />
</ehcache>

ok，配置文件都完成了，接着我们来编写controller、service和dao

1.CacheDemoController：

package com.netqin.function.cacheDemo;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
public class CacheDemoController {
	@Autowired
	private CacheDemoService service;

	@RequestMapping("/demo.do")
	public String handleIndex(Model model) {

		System.out.println(service.getName(0));
		model.addAttribute("name", service.getName(0));

		return "cacheDemo";
	}
	@RequestMapping("/demoFulsh.do")
 	public String handleFulsh(Model model) {
  		service.flush();
  		return "cacheDemo";
	 }
}

2.CacheDemoService ：

package com.netqin.function.cacheDemo;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springmodules.cache.annotations.CacheFlush;
import org.springmodules.cache.annotations.Cacheable;

@Service
public class CacheDemoService {
	@Autowired
	private CacheDemoDao dao;

	@Cacheable(modelId = "testCaching")
	public String getName(int id){
		System.out.println("Processing testCaching");
		return dao.getName(id);
	}

	@CacheFlush(modelId = "testFlushing")
	public void flush(){
		System.out.println("Processing testFlushing");
	}

}

我们只对service层加入了注解缓存配置。

接着我们来写一个简单的页面，cacheDemo.jsp：

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
CacheDemo:${name}
</body>
</html>

ok，一切就绪，我们启动服务器，并访问http://localhost:8080/cache/demo.do

多请求几次，请求两次的输出结果：

Processing testCaching
NameId:0
NameId:0

说明缓存起作用了，ok！

接着我们刷新该缓存，访问http://localhost:8080/cache/demoFulsh.do

再请求http://localhost:8080/cache/demo.do

输出结果：

Processing testCaching
NameId:0
NameId:0
Processing testFlushing
Processing testCaching
NameId:0

缓存刷新成功。