ehcache

package com.ge.energy.confirm.cache;

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;

public class EhCacheAfterAdvice implements AfterReturningAdvice,
  InitializingBean {
 private static final Log logger = LogFactory
   .getLog(EhCacheAfterAdvice.class);

 private Cache cache;

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

 public EhCacheAfterAdvice() {
  super();
 }

 public void afterReturning(Object arg0, Method arg1, Object[] arg2,
   Object arg3) throws Throwable {
  String className = arg3.getClass().getName();
  @SuppressWarnings("rawtypes")
  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);
   }
  }
 }

 public void afterPropertiesSet() throws Exception {
  Assert.notNull(cache,
    "Need a cache. Please use setCache(Cache) create it.");
 }

}
-------------------------------------------------------------------

package com.ge.energy.confirm.cache;

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

 private Cache cache;

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

 public EhCacheInterceptor() {
  super();
 }

 /**
  * Interceptor service .*find*.*，the result is or not exit，
  * if it is exitting return the cache result， otherwire，connect db ,
  * get dataset，& put the dataset into cache
  */
 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("Find object from cache is " + cache.getName());

  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();
 }

 /**
  * get cache key method，cache key is the one Cache of Element unqire id, cache key is
  * package+className+methodName，eg:com.ge.energy.confirm.service.BucketizationService.findModelsBySSOID(str)
  */
 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();
 }

 /**
  * implement InitializingBean，check cache or not null
  */
 public void afterPropertiesSet() throws Exception {
  Assert.notNull(cache,
    "Need a cache. Please use setCache(Cache) create it.");
 }

}
--------------------------------------------------------------------------

ehcache.xml

 

<?xml version="1.0" encoding="UTF-8"?>
<ehcache>
    <!-- <diskStore path="${jboss-home}\\server\\default\\deploy\\pgs.war\\cache"/>  -->
    <defaultCache
        maxElementsInMemory="10000"
        eternal="false"
        timeToIdleSeconds="120"
        timeToLiveSeconds="120"
        overflowToDisk="true"
        />
  <cache name="pgs_cache"
        maxElementsInMemory="100000"
        eternal="false"
        timeToIdleSeconds="300000"
        timeToLiveSeconds="600000"
        overflowToDisk="true"
        />
</ehcache>
-----------------------------------------------------

 <!-- the below that is passable annotation use spring spring aop -->
 <!-- get ehCache configuration file  -->
 <bean id="defaultCacheManager"
  class="org.springframework.cache.ehcache.EhCacheManagerFactoryBean">
  <property name="configLocation">
   <value>classpath:ehcache.xml</value>
  </property>
 </bean>

 <!-- definition ehCache factory，and set usefull Cache name -->
 <bean id="ehCache" class="org.springframework.cache.ehcache.EhCacheFactoryBean">
  <property name="cacheManager">
   <ref bean="defaultCacheManager" />
  </property>
  <property name="cacheName">
   <value>pgs_cache</value>
  </property>
 </bean>

 <!-- find/create cache interceptor -->
 <bean id="ehCacheInterceptor" class="com.ge.energy.confirm.cache.EhCacheInterceptor">
  <property name="cache">
   <ref bean="ehCache" />
  </property>
 </bean>

 <!-- flush cache interceptor -->
 <bean id="ehCacheAfterAdvice" class="com.ge.energy.confirm.cache.EhCacheAfterAdvice">
  <property name="cache">
   <ref bean="ehCache" />
  </property>
 </bean>

 <!-- Point -->
 <bean id="ehCachePointCut"
  class="org.springframework.aop.support.RegexpMethodPointcutAdvisor">
  <property name="advice">
   <ref bean="ehCacheInterceptor" />
  </property>
  <property name="patterns">
   <list>
    <value>.*find*.*</value>
   </list>
  </property>
 </bean>

 <!-- Point Advice -->
 <bean id="ehCachePointCutAdvice"
  class="org.springframework.aop.support.RegexpMethodPointcutAdvisor">
  <property name="advice">
   <ref bean="ehCacheAfterAdvice" />
  </property>
  <property name="patterns">
   <list>
    <value>.*save*.*</value>
    <value>.*update*.*</value>
    <value>.*delete*.*</value>
   </list>
  </property>
 </bean>

 <bean id="bucketizationServiceCache" class="org.springframework.aop.framework.ProxyFactoryBean">
  <property name="target">
   <ref bean="bucketizationService"></ref>
  </property>
  
  <property name="interceptorNames">
   <list>
     <value>ehCachePointCut</value>
           <value>ehCachePointCutAdvice</value>
   </list>
  </property>
 </bean>

 

/////////////////////////////////////////////////

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>