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。
首先来看一下目录结构,如下:
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。