- <diskStore>: 指定一个目录：当 EHCache 把数据写到硬盘上时, 将把数据写到这个目录下.
- <defaultCache>: 设置缓存的默认数据过期策略
- <cache> 设定具体的命名缓存的数据过期策略。每个命名缓存代表一个缓存区域
- 缓存区域(region)：一个具有名称的缓存块，可以给每一个缓存块设置不同的缓存策略。如果没有设置任何的缓存区域，则所有被缓存的对象，都将使用默认的缓存策略。即：<defaultCache.../>
- Hibernate在不同的缓存区域保存不同的类/集合。
--对于类而言，区域的名称是类名。如:com.atguigu.domain.Customer
--对于集合而言，区域的名称是类名加属性名。如com.atguigu.domain.Customer.orders
- cache 元素的属性
- name:设置缓存的名字,它的取值为类的全限定名或类的集合的名字
- maxInMemory:设置基于内存的缓存中可存放的对象最大数目
- eternal:设置对象是否为永久的,true表示永不过期,此时将忽略timeToIdleSeconds 和 timeToLiveSeconds属性; 默认值是false
- timeToIdleSeconds:设置对象空闲最长时间,以秒为单位, 超过这个时间,对象过期。当对象过期时,EHCache会把它从缓存中清除。如果此值为0,表示对象可以无限期地处于空闲状态。
- timeToLiveSeconds:设置对象生存最长时间,超过这个时间,对象过期。 如果此值为0,表示对象可以无限期地存在于缓存中. 该属性值必须大于或等于
- timeToIdleSeconds 属性值
- overflowToDisk:设置基于内存的缓存中的对象数目达到上限后,是否把溢出的对象写到基于硬盘的缓存中
下面是具体的配置文件：
<ehcache><!-- Sets the path to the directory where cache .data files are created.If the path is a Java System Property it is replaced byits value in the running VM.The following properties are translated:user.home - User's home directoryuser.dir - User's current working directoryjava.io.tmpdir - Default temp file path --><!--指定一个目录：当 EHCache 把数据写到硬盘上时, 将把数据写到这个目录下.--><diskStore path="java.io.tmpdir"/><!--Default Cache configuration. These will applied to caches programmatically created throughthe CacheManager.The following attributes are required for defaultCache:maxInMemory - Sets the maximum number of objects that will be created in memoryeternal - Sets whether elements are eternal. If eternal, timeouts are ignored and the elementis never expired.timeToIdleSeconds - Sets the time to idle for an element before it expires. Is only usedif the element is not eternal. Idle time is now - last accessed timetimeToLiveSeconds - Sets the time to live for an element before it expires. Is only usedif the element is not eternal. TTL is now - creation timeoverflowToDisk - Sets whether elements can overflow to disk when the in-memory cachehas reached the maxInMemory limit.--><!--设置缓存的默认数据过期策略 --><defaultCachemaxElementsInMemory="10000"eternal="false"timeToIdleSeconds="120"timeToLiveSeconds="120"overflowToDisk="true"/><!--Predefined caches. Add your cache configuration settings here.If you do not have a configuration for your cache a WARNING will be issued when theCacheManager startsThe following attributes are required for defaultCache:name - Sets the name of the cache. This is used to identify the cache. It must be unique.maxInMemory - Sets the maximum number of objects that will be created in memoryeternal - Sets whether elements are eternal. If eternal, timeouts are ignored and the elementis never expired.timeToIdleSeconds - Sets the time to idle for an element before it expires. Is only usedif the element is not eternal. Idle time is now - last accessed timetimeToLiveSeconds - Sets the time to live for an element before it expires. Is only usedif the element is not eternal. TTL is now - creation timeoverflowToDisk - Sets whether elements can overflow to disk when the in-memory cachehas reached the maxInMemory limit.--><!-- Sample cache named sampleCache1This cache contains a maximum in memory of 10000 elements, and will expirean element if it is idle for more than 5 minutes and lives for more than10 minutes.If there are more than 10000 elements it will overflow to thedisk cache, which in this configuration will go to wherever java.io.tmp isdefined on your system. On a standard Linux system this will be /tmp"--><!--具体类或集合缓存配置--><!--name:缓存的名字，取值为全类名或者集合的名字name="com.cache.entities.Department" 类级别缓存name="com.cache.entities.Department.emps" 集合级别缓存--><cache name="com.cache.entities.Department"maxElementsInMemory="10000"eternal="false"timeToIdleSeconds="300"timeToLiveSeconds="600"overflowToDisk="true"/><!-- Sample cache named sampleCache2This cache contains 1000 elements. Elements will always be held in memory.They are not expired. --><cache name="com.cache.entities.Department.emps"maxElementsInMemory="1000"eternal="true"timeToIdleSeconds="0"timeToLiveSeconds="0"overflowToDisk="false"/> --><!-- Place configuration for your caches following --></ehcache>