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。