成都心情

<ehcache>

??? <!—設置緩存文件 .data 的創建路徑。

???????? 如果該路徑是 Java 系統參數，當前虛擬機會重新賦值。

???????? 下面的參數這樣解釋：
???????? user.home – 用戶主目錄
???????? user.dir????? – 用戶當前工作目錄
???????? java.io.tmpdir – 默認臨時文件路徑 -->
??? <diskStore path="java.io.tmpdir"/>

??? <!—缺省緩存配置。CacheManager 會把這些配置應用到程序中。

??????? 下列屬性是 defaultCache 必須的：

??????? maxInMemory?????????? - 設定內存中創建對象的最大值。
??????? eternal??????????????????????? - 設置元素（譯注：內存中對象）是否永久駐留。如果是，將忽略超
??????????????????????????????????????????????時限制且元素永不消亡。
??????? timeToIdleSeconds? - 設置某個元素消亡前的停頓時間。
????????????????????????????????????????????? 也就是在一個元素消亡之前，兩次訪問時間的最大時間間隔值。
????????????????????????????????????????????? 這只能在元素不是永久駐留時有效（譯注：如果對象永恒不滅，則
????????????????????????????????????????????? 設置該屬性也無用）。
????????????????????????????????????????????? 如果該值是 0 就意味著元素可以停頓無窮長的時間。
??????? timeToLiveSeconds?- 為元素設置消亡前的生存時間。
?????????????????????????????????????????????? 也就是一個元素從構建到消亡的最大時間間隔值。
?????????????????????????????????????????????? 這只能在元素不是永久駐留時有效。
??????? overflowToDisk??????? - 設置當內存中緩存達到 maxInMemory 限制時元素是否可寫到磁盤
???????????????????????????????????????????????上。
??????? -->

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

<!-- ======================?? 緩存?? ======================= -->

<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>

/*
?* Copyright 2002-2004 the original author or authors.
?*
?* Licensed under the Apache License, Version 2.0 (the "License");
?* you may not use this file except in compliance with the License.
?* You may obtain a copy of the License at
?*
?*????? http://www.apache.org/licenses/LICENSE-2.0
?*
?* Unless required by applicable law or agreed to in writing, software
?* distributed under the License is distributed on an "AS IS" BASIS,
?* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
?* See the License for the specific language governing permissions and
?* limitations under the License.
?*/

package org.taha.interceptor;

import java.io.Serializable;

import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;

import org.apache.commons.logging.LogFactory;
import org.apache.commons.logging.Log;

import org.springframework.beans.factory.InitializingBean;
import org.springframework.util.Assert;

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

/**
?* @author <a href=" mailto:irbouh@gmail.com">Omar Irbouh</a>
?* @since 2004.10.07
?*/
public class MethodCacheInterceptor implements MethodInterceptor, InitializingBean {
? private static final Log logger = LogFactory.getLog(MethodCacheInterceptor.class);

? private Cache cache;

? /**
?? * 設置緩存名
?? */
? public void setCache(Cache cache) {
??? this.cache = cache;
? }

? /**
?? * 檢查是否提供必要參數。
?? */
? public void afterPropertiesSet() throws Exception {
??? Assert.notNull(cache, "A cache is required. Use setCache(Cache) to provide one.");
? }

? /**
?? * 主方法
?? * 如果某方法可被緩存就緩存其結果
?? * 方法結果必須是可序列化的(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("looking for method result in cache");
??? String cacheKey = getCacheKey(targetName, methodName, arguments);
??? Element element = cache.get(cacheKey);
??? if (element == null) {
????? //call target/sub-interceptor
????? logger.debug("calling intercepted method");
????? result = invocation.proceed();

????? //cache method result
????? logger.debug("caching result");
????? element = new Element(cacheKey, (Serializable) result);
????? cache.put(element);
??? }
??? return element.getValue();
? }

? /**
?? * creates cache key: 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();
? }
}

<bean id="methodCacheInterceptor" class="org.taha.interceptor.MethodCacheInterceptor">
? <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>.*methodOne</value>
????? <value>.*methodTwo</value>
??? </list>
? </property>
</bean>

<bean id="myBean" class="org.springframework.aop.framework.ProxyFactoryBean">
? <property name="target">
?? <bean class="org.taha.beans.MyBean"/>
? </property>
? <property name="interceptorNames">
??? <list>
????? <value>methodCachePointCut</value>
??? </list>
? </property>
</bean>