spring+ehcache 实现原理

package com.my.cache.ehcache; 

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; 

/** 
* ehCache 查询缓存处理 
* @author lyon.yao 
* 
*/ 
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(); 
} 

/* (non-Javadoc) 
* 检测cache对象是否为空 
* @see org.springframework.beans.factory.InitializingBean#afterPropertiesSet() 
*/ 
@Override 
public void afterPropertiesSet() throws Exception { 
Assert.notNull(cache, "cache is null,please set a new cache"); 
} 

/* (non-Javadoc) 
* 过滤service/dao 方法如果缓存中存在直接返回 否则从数据库中查找结果返回并放入缓存 
* @see org.aopalliance.intercept.MethodInterceptor#invoke(org.aopalliance.intercept.MethodInvocation) 
*/ 
@Override 
public Object invoke(MethodInvocation invocation) throws Throwable { 
Object result=null; 
String targetName = invocation.getThis().getClass().getName(); 
String methodName = invocation.getMethod().getName(); 
Object[] arguments = invocation.getArguments(); 
String cacheKey = getCacheKey(targetName, methodName, arguments); 
Element element = cache.get(cacheKey); 
if (element == null) { 
logger.debug("Hold up method , Get method result and create cache........!"); 
result = invocation.proceed(); 
element = new Element(cacheKey, (Serializable) result); 
cache.put(element); 
} 
return element.getValue(); 
} 
/** 
* 获得 cache key 的方法，cache key 是 Cache 中一个 Element 的唯一标识 
* cache key 包括　包名+类名+方法名，如 com.co.cache.service.UserServiceImpl.getAllUser 
* @param targetName 
* @param methodName 
* @param arguments 
* @return 
*/ 
private String getCacheKey(String targetName,String methodName,Object[] arguments) { 
StringBuffer key = new StringBuffer(); 
key.append(targetName).append(".").append(methodName); 
if ((arguments != null) && (arguments.length != 0)) { 
for (int i = 0; i < arguments.length; i++) { 
key.append(".").append(arguments[i]); 
} 
} 
return key.toString(); 
} 
} 

package com.my.cache.ehcache; 

import java.lang.reflect.Method; 
import java.util.List; 

import net.sf.ehcache.Cache; 

import org.apache.commons.logging.Log; 
import org.apache.commons.logging.LogFactory; 
import org.springframework.aop.AfterReturningAdvice; 
import org.springframework.beans.factory.InitializingBean; 
import org.springframework.util.Assert; 

/** 
* 功能:进行插入、修改、删除对cache的清理 
* @author lyon.yao 
* 
*/ 
public class MethodCacheAfterAdvice implements AfterReturningAdvice, 
InitializingBean { 
private static final Log logger = LogFactory.getLog(MethodCacheAfterAdvice.class); 
private Cache cache; 
public void setCache(Cache cache) { 
this.cache = cache; 
} 
public MethodCacheAfterAdvice() { 
super(); 
} 
/* (non-Javadoc) 
* 检测cache对象是否为空 
* @see org.springframework.beans.factory.InitializingBean#afterPropertiesSet() 
*/ 
@Override 
public void afterPropertiesSet() throws Exception { 
Assert.notNull(cache, "cache is null,please set a new cache"); 
} 

/* (non-Javadoc) 
* 刷新cache 
* @see org.springframework.aop.AfterReturningAdvice#afterReturning(java.lang.Object, java.lang.reflect.Method, java.lang.Object[], java.lang.Object) 
*/ 
@Override 
public void afterReturning(Object arg0, Method arg1, Object[] arg2, 
Object arg3) throws Throwable { 
String className = arg3.getClass().getName(); 
List list = cache.getKeys(); 
for(int i = 0;i<list.size();i++){ 
String cacheKey = String.valueOf(list.get(i)); 
if(cacheKey.startsWith(className)){ 
cache.remove(cacheKey); 
} 
logger.debug("remove cache " + cacheKey); 
} 
} 

}

 

<?xml version="1.0" encoding="UTF-8"?> 
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" 
"http://www.springframework.org/dtd/spring-beans.dtd"> 
<beans> 
<!-- 缓存管理 --> 
<bean id="cacheManager" class="org.springframework.cache.ehcache.EhCacheManagerFactoryBean" > 
<property name="configLocation"> 
<value>classpath:ehcache.xml</value> 
</property> 
</bean> 
<!-- 信息缓存 --> 
<bean id="ehCache" class="org.springframework.cache.ehcache.EhCacheFactoryBean"> 
<property name="cacheName"> 
<value>DEFAULT_CACHE</value> 
</property> 
<property name="cacheManager" ref="cacheManager" /> 
</bean> 
<!-- find/create cache 拦截器 --> 
<bean id="methodCacheInterceptor" 
class="com.my.cache.ehcache.MethodCacheInterceptor"> 
<property name="cache"> 
<ref local="ehCache" /> 
</property> 
</bean> 
<!-- flush cache 拦截器 --> 
<bean id="methodCacheAfterAdvice" 
class="com.my.cache.ehcache.MethodCacheAfterAdvice"> 
<property name="cache"> 
<ref local="ehCache" /> 
</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> 
<value>.*list.*</value> 
<value>.*query.*</value> 
</list> 
</property> 
</bean> 
<bean id="methodCachePointCutAdvice" 
class="org.springframework.aop.support.RegexpMethodPointcutAdvisor"> 
<property name="advice"> 
<ref local="methodCacheAfterAdvice"/> 
</property> 
<property name="patterns"> 
<list> 
<value>.*add.*</value> 
<value>.*create.*</value> 
<value>.*update.*</value> 
<value>.*delete.*</value> 
<value>.*remove.*</value> 
</list> 
</property> 
</bean> 
</beans>

<?xml version="1.0" encoding="UTF-8"?> 
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" 
"http://www.springframework.org/dtd/spring-beans.dtd"> 
<beans> 
<import resource="cacheContext.xml"/> 
<bean id="testServiceTarget" class="com.co.cache.test.TestServiceImpl"/> 
<bean id="testService" class="org.springframework.aop.framework.ProxyFactoryBean"> 
<property name="target"> 
<ref local="testServiceTarget"/> 
</property> 
<property name="interceptorNames"> 
<list> 
<value>methodCachePointCut</value> 
<value>methodCachePointCutAdvice</value> 
</list> 
</property> 
</bean> 
</beans>