paulwong

SPRING CACHE之ConcurrentMapCacheManager改造

1. pom.xml中加入依赖包
   
           <dependency>
               <groupId>com.google.guava</groupId>
               <artifactId>guava</artifactId>
               <version>18.0</version>
           </dependency>
   
   
2. 改造CacheManager，MyConcurrentMapCacheManager
   
   package com.paul.common.cache;
   /*
    * Copyright 2002-2014 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.
    */
   
   import java.util.Collection;
   import java.util.Collections;
   import java.util.Map;
   import java.util.concurrent.ConcurrentHashMap;
   import java.util.concurrent.ConcurrentMap;
   import java.util.concurrent.TimeUnit;
   
   import org.springframework.cache.Cache;
   import org.springframework.cache.CacheManager;
   import org.springframework.cache.concurrent.ConcurrentMapCache;
   
   import com.google.common.cache.CacheBuilder;
   
   /**
    * {@link CacheManager} implementation that lazily builds {@link ConcurrentMapCache}
    * instances for each {@link #getCache} request. Also supports a 'static' mode where
    * the set of cache names is pre-defined through {@link #setCacheNames}, with no
    * dynamic creation of further cache regions at runtime.
    *
    * <p>Note: This is by no means a sophisticated CacheManager; it comes with no
    * cache configuration options. However, it may be useful for testing or simple
    * caching scenarios. For advanced local caching needs, consider
    * {@link org.springframework.cache.guava.GuavaCacheManager} or
    * {@link org.springframework.cache.ehcache.EhCacheCacheManager}.
    *
    * @author Juergen Hoeller
    * @since 3.1
    * @see ConcurrentMapCache
    */
   public class MyConcurrentMapCacheManager implements CacheManager {
   
       private final ConcurrentMap<String, Cache> cacheMap = new ConcurrentHashMap<String, Cache>(16);
   
       private boolean dynamic = true;
   
       private boolean allowNullValues = true;
       
       private long expireTime = 30;
       
       private long maximumSize = 100;
   
   
       /**
        * Construct a dynamic ConcurrentMapCacheManager,
        * lazily creating cache instances as they are being requested.
        */
       public MyConcurrentMapCacheManager() {
       }
   
       /**
        * Construct a static ConcurrentMapCacheManager,
        * managing caches for the specified cache names only.
        */
       public MyConcurrentMapCacheManager(long expireTime, long maximumSize) {
           if(expireTime > 0)
               this.expireTime = expireTime;
           if(maximumSize > 0)
               this.maximumSize = maximumSize;
       }
   
   
       /**
        * Specify the set of cache names for this CacheManager's 'static' mode.
        * <p>The number of caches and their names will be fixed after a call to this method,
        * with no creation of further cache regions at runtime.
        * <p>Calling this with a {@code null} collection argument resets the
        * mode to 'dynamic', allowing for further creation of caches again.
        */
       public void setCacheNames(Collection<String> cacheNames) {
           if (cacheNames != null) {
               for (String name : cacheNames) {
                   this.cacheMap.put(name, createConcurrentMapCache(name));
               }
               this.dynamic = false;
           }
           else {
               this.dynamic = true;
           }
       }
   
       /**
        * Specify whether to accept and convert {@code null} values for all caches
        * in this cache manager.
        * <p>Default is "true", despite ConcurrentHashMap itself not supporting {@code null}
        * values. An internal holder object will be used to store user-level {@code null}s.
        * <p>Note: A change of the null-value setting will reset all existing caches,
        * if any, to reconfigure them with the new null-value requirement.
        */
       public void setAllowNullValues(boolean allowNullValues) {
           if (allowNullValues != this.allowNullValues) {
               this.allowNullValues = allowNullValues;
               // Need to recreate all Cache instances with the new null-value configuration
               for (Map.Entry<String, Cache> entry : this.cacheMap.entrySet()) {
                   entry.setValue(createConcurrentMapCache(entry.getKey()));
               }
           }
       }
   
       /**
        * Return whether this cache manager accepts and converts {@code null} values
        * for all of its caches.
        */
       public boolean isAllowNullValues() {
           return this.allowNullValues;
       }
   
   
       @Override
       public Collection<String> getCacheNames() {
           return Collections.unmodifiableSet(this.cacheMap.keySet());
       }
   
       @Override
       public Cache getCache(String name) {
           Cache cache = this.cacheMap.get(name);
           if (cache == null && this.dynamic) {
               synchronized (this.cacheMap) {
                   cache = this.cacheMap.get(name);
                   if (cache == null) {
                       cache = createConcurrentMapCache(name);
                       this.cacheMap.put(name, cache);
                   }
               }
           }
           return cache;
       }
   
       /**
        * Create a new ConcurrentMapCache instance for the specified cache name.
        * @param name the name of the cache
        * @return the ConcurrentMapCache (or a decorator thereof)
        */
       protected Cache createConcurrentMapCache(String name) {
           //return new ConcurrentMapCache(name, isAllowNullValues());
           //此处改用GOOGLE GUAVA的构造MANAGER方式
           return new ConcurrentMapCache(name,
                                           CacheBuilder.newBuilder()
                                                       .expireAfterWrite(this.expireTime, TimeUnit.MINUTES)
                                                       .maximumSize(this.maximumSize)
                                                       .build()
                                                       .asMap(), 
                                           isAllowNullValues());
       }
   
   }
   
   
   
3. 配置想着bean, cache-concurrentmap-applicationcontext.xml
   
   <?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:context="http://www.springframework.org/schema/context"
       xmlns:cache="http://www.springframework.org/schema/cache"
       xmlns:p="http://www.springframework.org/schema/p"
       xmlns:c="http://www.springframework.org/schema/c"
       xmlns:jee="http://www.springframework.org/schema/jee"
       xmlns:util="http://www.springframework.org/schema/util"
       xsi:schemaLocation="http://www.springframework.org/schema/context
             http://www.springframework.org/schema/context/spring-context-3.0.xsd
             http://www.springframework.org/schema/beans
             http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
             http://www.springframework.org/schema/cache
             http://www.springframework.org/schema/cache/spring-cache.xsd
             http://www.springframework.org/schema/jee 
             http://www.springframework.org/schema/jee/spring-jee.xsd
             http://www.springframework.org/schema/util
             http://www.springframework.org/schema/util/spring-util.xsd">
   
       <cache:annotation-driven />
   
       <!-- <bean id="cacheManager"
           class="org.springframework.cache.concurrent.ConcurrentMapCacheManager" >
           <property name="cacheNames">
               <list>
                   <value>my-local-cache</value>
               </list>
           </property>
       </bean> -->
       
       <bean id="cacheManager"
           class="com.paul.common.cache.MyConcurrentMapCacheManager">
           <constructor-arg index="0" value="1" />
           <constructor-arg index="1" value="5000" />
       </bean>    
       
   </beans>
   
   
   
4. 通过注释进行使用
   
   /*
    * JBoss, Home of Professional Open Source
    * Copyright 2014, Red Hat, Inc. and/or its affiliates, and individual
    * contributors by the @authors tag. See the copyright.txt in the
    * distribution for a full listing of individual contributors.
    *
    * 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 com.paul.springmvc.data;
   
   import java.util.List;
   
   import javax.persistence.EntityManager;
   import javax.persistence.criteria.CriteriaBuilder;
   import javax.persistence.criteria.CriteriaQuery;
   import javax.persistence.criteria.Root;
   
   import org.springframework.beans.factory.annotation.Autowired;
   import org.springframework.cache.annotation.CacheEvict;
   import org.springframework.cache.annotation.Cacheable;
   import org.springframework.stereotype.Repository;
   import org.springframework.transaction.annotation.Transactional;
   
   import com.paul.springmvc.model.Member;
   
   @Repository
   @Transactional
   public class MemberDaoImpl implements MemberDao {
       @Autowired
       private EntityManager em;
   
       @Cacheable(value = "my-local-cache", key = "#id")
       public Member findById(Long id) {
           System.out.println("MemberDaoImpl NO CACHE");
           return em.find(Member.class, id);
       }
   
       public Member findByEmail(String email) {
           CriteriaBuilder cb = em.getCriteriaBuilder();
           CriteriaQuery<Member> criteria = cb.createQuery(Member.class);
           Root<Member> member = criteria.from(Member.class);
   
           /*
            * Swap criteria statements if you would like to try out type-safe criteria queries, a new
            * feature in JPA 2.0 criteria.select(member).orderBy(cb.asc(member.get(Member_.name)));
            */
   
           criteria.select(member).where(cb.equal(member.get("email"), email));
           return em.createQuery(criteria).getSingleResult();
       }
   
       public List<Member> findAllOrderedByName() {
           CriteriaBuilder cb = em.getCriteriaBuilder();
           CriteriaQuery<Member> criteria = cb.createQuery(Member.class);
           Root<Member> member = criteria.from(Member.class);
   
           /*
            * Swap criteria statements if you would like to try out type-safe criteria queries, a new
            * feature in JPA 2.0 criteria.select(member).orderBy(cb.asc(member.get(Member_.name)));
            */
   
           criteria.select(member).orderBy(cb.asc(member.get("name")));
           return em.createQuery(criteria).getResultList();
       }
   
       @CacheEvict(value="my-local-cache",allEntries=true,beforeInvocation=true)//清空所有缓存
       public void register(Member member) {
           em.persist(member);
           return;
       }
   }

posted on 2015-02-25 16:34 paulwong 阅读(2638) 评论(0)  编辑  收藏 所属分类: SPRING 、性能优化 、缓存