Sprng ecache

Ehcache是一种广泛使用的开源java分布式缓存,它具有内存和磁盘存储，缓存加载器,缓存扩展,缓存异常处理程序,一个gzip缓存servlet过滤器,支持REST和SOAP api等特点。

主要的特性有：

1. 快速

2. 简单

3. 多种缓存策略

4. 缓存数据有两级：内存和磁盘，因此无需担心容量问题

5. 缓存数据会在虚拟机重启的过程中写入磁盘

6. 可以通过RMI、可插入API等方式进行分布式缓存

7. 具有缓存和缓存管理器的侦听接口

8. 支持多缓存管理器实例，以及一个实例的多个缓存区域

9. 提供Hibernate的缓存实现

1. 依赖

<dependency>
           <groupId>net.sf.ehcache</groupId>
           <artifactId>ehcache</artifactId>
           <version>2.7.4</version>
       </dependency>
       <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context-support</artifactId>
            <version>${spring.version}</version>
       </dependency>

2. xml文件中增加命名空间

xmlns:p="http://www.springframework.org/schema/p"

xmlns:cache="http://www.springframework.org/schema/cache"

http://www.springframework.org/schema/cache
http://www.springframework.org/schema/cache/spring-cache.xsd

3. 添加如下声明

<cache:annotation-driven cache-manager="cacheManager" />
   
   <bean id="ehcache" class="org.springframework.cache.ehcache.EhCacheManagerFactoryBean"
       p:config-location="classpath:ehcache.xml"
       p:shared="true"
       />
   
   <bean id="cacheManager" class="org.springframework.cache.ehcache.EhCacheCacheManager"
       p:cache-manager-ref="ehcache" />

4. ehcache.xml

<?xml version="1.0" encoding="UTF-8"?>

<ehcache name="functionRestCache" updateCheck="false">
   
   <cache name="cache5s" eternal="false" maxElementsInMemory="9999"
       overflowToDisk="false" diskPersistent="false" timeToIdleSeconds="0"
       timeToLiveSeconds="5" memoryStoreEvictionPolicy="LFU" />

   <cache name="cache1m" eternal="false" maxElementsInMemory="9999"
       overflowToDisk="false" diskPersistent="false" timeToIdleSeconds="0"
       timeToLiveSeconds="60" memoryStoreEvictionPolicy="LFU" />

   <cache name="cache5m" eternal="false" maxElementsInMemory="19999"
       overflowToDisk="false" diskPersistent="false" timeToIdleSeconds="0"
       timeToLiveSeconds="300" memoryStoreEvictionPolicy="LFU" />

   <cache name="cache30m" eternal="false" maxElementsInMemory="19999"
       overflowToDisk="false" diskPersistent="false" timeToIdleSeconds="0"
       timeToLiveSeconds="1800" memoryStoreEvictionPolicy="LFU" />

</ehcache>

5. 常见异常

spring错误-在spring里面找不到org.springframework.cache.ehcache.EhCacheManagerFactoryBean

缺少spring-context-support-3.2.0.jar这个jar包

Caused by: net.sf.ehcache.CacheException: Another CacheManager with same name '' already exists in the same VM. Please provide unique names for each CacheManager in the config or do one of following:
1. Use one of the CacheManager.create() static factory methods to reuse same CacheManager with same name or create one if necessary
2. Shutdown the earlier cacheManager before creating new one with same name.
The source of the existing CacheManager is: DefaultConfigurationSource [ ehcache.xml or ehcache-failsafe.xml ]