Spring集成Ehcache[整理]

http://blog.csdn.net/upyaya/archive/2007/05/21/1619411.aspx

原文地址：
http://opensource.atlassian.com/confluence/spring/display/DISC/Caching+the+result+of+methods+using+Spring+and+EHCache导言从 Spring 1.1.1 开始，EHCache 就作为一种通用缓存解决方案集成进 Spring。我将示范拦截器的例子，它能把方法返回的结果缓存起来。?利用 Spring IoC 配置 EHCache在 Spring 里配置 EHCache 很简单。你只需一个 ehcache.xml 文件，该文件用于配置 EHCache：<ehcache>

????<!—设置缓存文件?.data?的创建路径。

?????????如果该路径是?Java?系统参数，当前虚拟机会重新赋值。

?????????下面的参数这样解释：
?????????user.home??用户主目录
?????????user.dir???????用户当前工作目录
?????????java.io.tmpdir??默认临时文件路径?-->
????<diskStore?path="java.io.tmpdir"/>


????<!—缺省缓存配置。CacheManager?会把这些配置应用到程序中。

????????下列属性是?defaultCache?必须的：

????????maxInMemory???????????-?设定内存中创建对象的最大值。
????????eternal????????????????????????-?设置元素（译注：内存中对象）是否永久驻留。如果是，将忽略超
??????????????????????????????????????????????时限制且元素永不消亡。
????????timeToIdleSeconds??-?设置某个元素消亡前的停顿时间。
??????????????????????????????????????????????也就是在一个元素消亡之前，两次访问时间的最大时间间隔值。
??????????????????????????????????????????????这只能在元素不是永久驻留时有效（译注：如果对象永恒不灭，则
??????????????????????????????????????????????设置该属性也无用）。
??????????????????????????????????????????????如果该值是?0?就意味着元素可以停顿无穷长的时间。
????????timeToLiveSeconds?-?为元素设置消亡前的生存时间。
???????????????????????????????????????????????也就是一个元素从构建到消亡的最大时间间隔值。
???????????????????????????????????????????????这只能在元素不是永久驻留时有效。
????????overflowToDisk????????-?设置当内存中缓存达到?maxInMemory?限制时元素是否可写到磁盘
???????????????????????????????????????????????上。
????????-->

????<cache?name="org.taha.cache.METHOD_CACHE"
????????maxElementsInMemory="300"
????????eternal="false"
????????timeToIdleSeconds="500"
????????timeToLiveSeconds="500"
????????overflowToDisk="true"
????????/>
</ehcache>

拦截器将使用 ”org.taha.cache.METHOD_CACHE” 区域缓存方法返回结果。下面利用 Spring IoC 让 bean 来访问这一区域。

<!--?======================???缓存???=======================?-->

<bean?id="cacheManager"?class="org.springframework.cache.ehcache.EhCacheManagerFactoryBean">
??<property?name="configLocation">
????<value>classpath:ehcache.xml</value>
??</property>
</bean>

<bean?id="methodCache"?class="org.springframework.cache.ehcache.EhCacheFactoryBean">
??<property?name="cacheManager">
????<ref?local="cacheManager"/>
??</property>
??<property?name="cacheName">
????<value>org.taha.cache.METHOD_CACHE</value>
??</property>
</bean>

?

构建我们的 MethodCacheInterceptor该拦截器实现org.aopalliance.intercept.MethodInterceptor接口。一旦运行起来(kicks-in)，它首先检查被拦截方法是否被配置为可缓存的。这将可选择性的配置想要缓存的 bean 方法。只要调用的方法配置为可缓存，拦截器将为该方法生成 cache key 并检查该方法返回的结果是否已缓存。如果已缓存，就返回缓存的结果，否则再次调用被拦截方法，并缓存结果供下次调用。?com.ph.serviceportal.infoboard.util.MethodCacheInterceptor?package?com.ph.serviceportal.infoboard.util;

import?java.io.Serializable;

import?net.sf.ehcache.Cache;
import?net.sf.ehcache.Element;

import?org.aopalliance.intercept.MethodInterceptor;
import?org.aopalliance.intercept.MethodInvocation;
import?org.apache.commons.logging.Log;
import?org.apache.commons.logging.LogFactory;
import?org.springframework.beans.factory.InitializingBean;
import?org.springframework.util.Assert;

public?class?MethodCacheInterceptor?implements?MethodInterceptor,
????????InitializingBean?...{
????private?static?final?Log?logger?=?LogFactory
????????????.getLog(MethodCacheInterceptor.class);

????private?Cache?cache;

????public?void?setCache(Cache?cache)?...{
????????this.cache?=?cache;
????}

????/**?*//**?
?????*??
?????*/
????public?MethodCacheInterceptor()?...{
????????super();
????????//?TODO?自动生成构造函数存根??
????}

????/**?*//**?
?????*?主方法?
?????*?如果某方法可被缓存就缓存其结果?
?????*?方法结果必须是可序列化的(serializable)?
?????*/
????public?Object?invoke(MethodInvocation?invocation)?throws?Throwable?...{
????????String?targetName?=?invocation.getThis().getClass().getName();
????????String?methodName?=?invocation.getMethod().getName();
????????Object[]?arguments?=?invocation.getArguments();
????????Object?result;

????????logger.debug("在缓存中查找方法返回的对象!");
????????String?cacheKey?=?getCacheKey(targetName,?methodName,?arguments);
????????Element?element?=?cache.get(cacheKey);
????????if?(element?==?null)?...{
????????????logger.debug("正在拦截方法!");
????????????result?=?invocation.proceed();

????????????logger.debug("正在缓存对象!");
????????????element?=?new?Element(cacheKey,?(Serializable)result);
????????????cache.put(element);
????????}
????????return?element.getValue();
????}

????/**?*//**?
?????*创建一个缓存对象的标识:?targetName.methodName.argument0.argument1...?
?????*/
????private?String?getCacheKey(String?targetName,?String?methodName,
????????????Object[]?arguments)?...{
????????StringBuffer?sb?=?new?StringBuffer();
????????sb.append(targetName).append(".").append(methodName);
????????if?((arguments?!=?null)?&&?(arguments.length?!=?0))?...{
????????????for?(int?i?=?0;?i?<?arguments.length;?i++)?...{
????????????????sb.append(".").append(arguments[i]);
????????????}
????????}

????????return?sb.toString();
????}

????/**//*?（非?Javadoc）?
?????*?@see?org.springframework.beans.factory.InitializingBeanafterPropertiesSet()?
?????*/
????public?void?afterPropertiesSet()?throws?Exception?...{
????????Assert.notNull(cache,?"需要一个缓存.?使用setCache(Cache)分配一个.");

????}
}

? com.ph.serviceportal.infoboard.util.MethodCacheAfterAdvice?

?package?com.ph.serviceportal.infoboard.util;

import?java.lang.reflect.Method;

import?net.sf.ehcache.Cache;

import?org.springframework.aop.AfterReturningAdvice;
import?org.springframework.beans.factory.InitializingBean;
import?org.springframework.util.Assert;

public?class?MethodCacheAfterAdvice?implements?AfterReturningAdvice,
????????InitializingBean?...{

????private?Cache?cache;

????public?void?setCache(Cache?cache)?...{
????????this.cache?=?cache;
????}

????/**?*//**
?????*?
?????*/
????public?MethodCacheAfterAdvice()?...{
????????super();
????}

????/**//*
?????*?（非?Javadoc）
?????*?
?????*?@see?org.springframework.aop.AfterReturningAdviceafterReturning(java.lang.Object,
?????*??????java.lang.reflect.Method,?java.lang.Object[],?java.lang.Object)
?????*/
????public?void?afterReturning(Object?arg0,?Method?arg1,?Object[]?arg2,
????????????Object?arg3)?throws?Throwable?...{
????????StringBuffer?buffer?=?new?StringBuffer();
????????buffer.append(arg3.getClass().getName()).append(".").append(
????????????????arg1.getName());
????????if?(arg2?!=?null?&&?arg2.length?!=?0)?...{
????????????for?(int?i?=?0;?i?<?arg2.length;?i++)?...{
????????????????buffer.append(".").append(arg2[i]);
????????????}

????????}
????????cache.remove(buffer);
????}

????/**//*
?????*?（非?Javadoc）
?????*?
?????*?@see?org.springframework.beans.factory.InitializingBeanafterPropertiesSet()
?????*/
????public?void?afterPropertiesSet()?throws?Exception?...{
????????Assert.notNull(cache,?"需要一个缓存.?使用setCache(Cache)分配一个.");
????}
}
MethodCacheInterceptor 代码说明了：

默认条件下，所有方法返回结果都被缓存了（methodNames 是 null） 缓存区利用 IoC 形成 cacheKey 的生成还包括方法参数的因素（译注：参数的改变会影响 cacheKey） 使用 MethodCacheInterceptor下面摘录了怎样配置 MethodCacheInterceptor and MethodCacheAfterAdvice：<bean?id="methodCacheInterceptor"
????????class="com.ph.serviceportal.infoboard.util.MethodCacheInterceptor">
????????<property?name="cache">
????????????<ref?local="methodCache"?/>
????????</property>
????</bean>
????<bean?id="methodCacheAfterAdvice"
????????class="com.ph.serviceportal.infoboard.util.MethodCacheAfterAdvice">
????????<property?name="cache">
????????????<ref?local="methodCache"?/>
????????</property>
????</bean>
????<bean?id="methodCachePointCut"
????????class="org.springframework.aop.support.RegexpMethodPointcutAdvisor">
????????<property?name="advice">
????????????<ref?local="methodCacheInterceptor"?/>
????????</property>
????????<property?name="patterns">
????????????<list>
????????????????<value>.*find.*</value>
????????????????<value>.*get.*</value>
????????????</list>
????????</property>
????</bean>
????<bean?id="methodCacheAdvicePointCut"
????????class="org.springframework.aop.support.RegexpMethodPointcutAdvisor">
????????<property?name="advice">
????????????<ref?local="methodCacheAfterAdvice"?/>
????????</property>
????????<property?name="patterns">
????????????<list>
????????????????<value>.*upd.*</value>
????????????????<value>.*save.*</value>
????????????????<value>.*delete.*</value>
????????????</list>
????????</property>
????</bean>结合上一篇文章，我们有如下配置：?spring+JAX-RPC(Axis) 构建webservice????<bean?name="infoboardService"
????????class="com.ph.serviceportal.infoboard.service.InfoBoardServiceImpl">
????????<property?name="dataRetriever"?ref="infoboardDAO"?/>
????</bean>

????<bean?name="infoboardDAO"
????????class="com.ph.serviceportal.infoboard.dao.InfoboardDAOImpl">
????????<property?name="infoboardDAO">
????????????<ref?local="infoboardServiceRpcProxy"?/>
????????</property>
????</bean>

????<bean?id="infoboardServiceRpcProxy"
????????class="org.springframework.remoting.jaxrpc.JaxRpcPortProxyFactoryBean">
????????<property?name="serviceInterface">
????????????<value>
????????????????com.hp.serviceportal.infoboard.dao.IInfoboardDAO
????????????</value>
????????</property>
????????<property?name="wsdlDocumentUrl">
????????????<value>
????????????????http://qatest17.mro.cpqcorp.net/infoboard_ws_1100/infoboard.asmx?wsdl
????????????</value>
????????</property>
????????<property?name="namespaceUri">
????????????<value>http://tempuri.org/InfoBoard_WS/Service1</value>
????????</property>
????????<property?name="serviceName">
????????????<value>Service1</value>
????????</property>
????????<property?name="portName">
????????????<value>Service1Soap</value>
????????</property>
????????<property?name="portInterface">
????????????<value>
????????????????org.tempuri.InfoBoard_WS.Service1.Service1Soap
????????????</value>
????????</property>
????</bean>对infoboardservice进行增强:????<bean?id="infoboardServiceCacheProxy"
????????class="org.springframework.aop.framework.ProxyFactoryBean">
????????<property?name="proxyInterfaces">
????????????<value>com.ph.serviceportal.infoboard.service.IInfoBoardService</value>
????????</property>
????????<property?name="target">
????????????<ref?local="infoboardService"?/>
????????</property>
????????<property?name="interceptorNames">
????????????<list>
????????????????<value>methodCachePointCut</value>
????????????????<value>methodCacheAfterAdvice</value>
????????????</list>
????????</property>
????</bean>

<完>

?