EHCache And Aspect Demo

EHCache配置文件ehcache.xml

<?xml version="1.0" encoding="UTF-8"?>
<ehcache>
	<defaultCache
			maxElementsInMemory="1000"
			eternal="false"
			timeToIdleSeconds="3600"
			timeToLiveSeconds="7200"
			memoryStoreEvictionPolicy="LFU">
	</defaultCache>
	<cache name="StuCache"
		maxElementsInMemory="200"
			eternal="false"
			timeToIdleSeconds="300"
			timeToLiveSeconds="600"
			memoryStoreEvictionPolicy="LFU">
	</cache>
</ehcache>

Spring相关配置

<?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:aop="http://www.springframework.org/schema/aop"  xmlns:tx="http://www.springframework.org/schema/tx" 
    xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans 
	http://www.springframework.org/schema/beans/spring-beans-2.5.xsd http://www.springframework.org/schema/aop 
	http://www.springframework.org/schema/aop/spring-aop-2.5.xsd http://www.springframework.org/schema/tx 
	http://www.springframework.org/schema/tx/spring-tx-2.5.xsd http://www.springframework.org/schema/context
	http://www.springframework.org/schema/context/spring-context-2.5.xsd" >  
	<!-- 启动@AspectJ支持 -->
	<aop:aspectj-autoproxy/> 
	<!-- 定义切面类 -->
	<bean class="zl.AspectDemo"/>
	
	<!-- 引用ehCache的配置和管理类 -->     
	<bean id="defaultCacheManager" class="org.springframework.cache.ehcache.EhCacheManagerFactoryBean">     
  		 <property name="configLocation">     
   			<value>classpath:ehcache.xml</value>     
  		 </property>     
	</bean>     
   
	<!-- 定义ehCacheBean，并设置所使用的缓存名字 -->     
	<bean id="ehCache" class="org.springframework.cache.ehcache.EhCacheFactoryBean">     
 		 <property name="cacheManager">     
  			 <ref local="defaultCacheManager"/>     
  		 </property>     
  	 	 <property name="cacheName">     
     		 <value>StuCache</value>    
   		 </property>     
	</bean>     
</beans>

以下为核心切面Bean代码

package zl.aop;

import javax.annotation.Resource;

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

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Pointcut;

//注解表示这个为切面Bean
@Aspect
public class AspectDemo {
	
	private static final Log logger = LogFactory.getLog(StudentAction.class);
	
	private Cache  cache;
	//注入缓存容器
	@Resource(name="ehCache")												
	public void setCache(Cache cache) {
		this.cache = cache;
	}

	//定义一个切入点：业务层中所有以Impl结尾的类的get方法 参数不限 返回值不限
	@Pointcut("execution(* zl.service.impl.*Impl.get*(..))")
	public void demoPointcut(){}	
	
	//环绕增强 切入段为demoPointcut
	@Around("demoPointcut()")
	public Object demo(ProceedingJoinPoint jp) throws Throwable{
		//得到 目标对象名
		String targetName = jp.getTarget().toString();
		//得到 目标方法名
		String methodName = jp.getSignature().getName();
		//得到 目标方法参数个数
		int argLength = jp.getArgs().length;
		//拼接一个由以上3个组成的可以作为唯一键的字符串
		String cacheKey = getCacheKey(targetName, methodName, argLength);
		//在缓存中用key查找
		Element element = cache.get(cacheKey);
		if(element == null){
			//如果没有
			logger.debug("缓存中没有，执行数据访问读取数据...");
			// proceed(..)为执行目标方法   jp.getArgs()为方法的参数
			Object result = jp.proceed(jp.getArgs());
			//创建一个新的缓存对象
			element = new Element(cacheKey,result);
			//放入缓存容器
			cache.put(element);
		}
		//返回 缓存对象所封装的结果集
		return element.getObjectValue();
	}
	
	//拼接一个key
	private String getCacheKey(String targetName,String methodName,int argLength){
		StringBuffer sb = new StringBuffer();
		sb.append(targetName).append("_")
			.append(methodName).append("_")
			.append(argLength);
		return sb.toString();
	}
}

以下为ehcache的jar以及aspect支持所需jar