Ehcache 页面缓存
Posted 崔耀强
tags:
篇首语：本文由小常识网(cha138.com)小编为大家整理，主要介绍了Ehcache 页面缓存相关的知识，希望对你有一定的参考价值。
页面缓存，毫无疑问，几乎所有的网站的首页都是访问率最高的，而首页上的数据来源又是非常广泛的，大多数来自不同的对象，而且有可能来自不同的db ，所以给首页做缓存是一个不错的主意，那么主页的缓存策略是什么样子的呢，我认为应该是某个固定时间之内不变的，比如说2 分钟更新一次。那么这个缓存应该做在什么地方呢，让我们来看一下，假设您的应用的结构是page-filter-action-service-dao-db ，这个过程中的- 的地方都是可以做缓存的地方，根据页面缓存的特征，应该把页面缓存做到尽量靠近客户的地方，就是在page 和filter 之间，这样的优点就是第一个用户请求之后，页面被缓存，第二个用户再来请求的时候，走到filter 这个请求就结束了，无需再走后面的action-service-dao-db 。带来的好处是服务器压力的减低和客户段页面响应速度的加快。
页面缓存主要用Filter过滤器对请求的url进行过滤，如果该url在缓存中出现。那么页面数据就从缓存对象中获取，并以gzip压缩后返回。其速度是没有压缩缓存时速度的3-5倍，效率相当之高！
其中页面缓存的过滤器有CachingFilter，一般要扩展filter或是自定义Filter都继承该CachingFilter。
编写页面缓存的步骤如下：
项目结构：
1）添加相应的jar，
，这里使用的是2.5的jar。
2）在web.xml中添加缓存过滤器配置。
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
<display-name>20160623PageCache</display-name>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>index.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.jsp</welcome-file>
</welcome-file-list>
<!-- 配置缓存并gzip压缩页面数据的核心过滤器 -->
<filter>
<filter-name>PageEhCacheFilter</filter-name>
<filter-class>com.ghj.packageoffilter.PageEhCacheFilter</filter-class>
<!-- 需要缓存的页面url -->
<init-param>
<param-name>patterns</param-name>
<param-value>/index.jsp</param-value>
</init-param>
<!-- 配置该过滤器所使用的ehcache,值得注意的是：也可以不配置cacheName属性，
但这时“ehcache.xml”文件中第44行代码的name属性必须为SimplePageCachingFilter，
因为PageEhCacheFilter类继承的SimplePageCachingFilter类中设定了cacheName的值为“SimplePageCachingFilter”；
如果在这里指定了cacheName属性，那么“ehcache.xml”文件中第44行代码的name属性的属性值必须和所配置的一致
-->
<init-param>
<param-name>cacheName</param-name>
<param-value>PageEhCacheFilter</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>PageEhCacheFilter</filter-name>
<url-pattern>*.action</url-pattern>
</filter-mapping>
<filter-mapping>
<filter-name>PageEhCacheFilter</filter-name>
<url-pattern>*.jsp</url-pattern>
</filter-mapping>
</web-app>
3）添加Ehcache的相关配置文件。
ehcache.xml
<?xml version="1.0" encoding="UTF-8"?>
<ehcache xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:noNamespaceSchemaLocation="ehcache.xsd" updateCheck="true"
monitoring="autodetect" dynamicConfig="true">
<!--
diskStore ：指定数据存储位置，可指定磁盘中的文件夹位置
-->
<diskStore path="java.io.tmpdir/ehcache" />
<!--
defaultCache： 默认的管理策略
diskPersistent： 是否在磁盘上持久化。指重启jvm后，数据是否有效。默认为false。
diskExpiryThreadIntervalSeconds： 对象检测线程运行时间间隔。标识对象状态的线程多长时间运行一次。
这个Cache不能删除，否则会抛出No default cache is configured异常
-->
<defaultCache
maxEntriesLocalHeap="10000"
maxEntriesLocalDisk="10000000"
eternal="false"
timeToIdleSeconds="120"
timeToLiveSeconds="120"
overflowToDisk="true"
diskSpoolBufferSizeMB="30"
diskPersistent="false"
diskExpiryThreadIntervalSeconds="120"
memoryStoreEvictionPolicy="LRU" />
<!--配置自定义缓存：
name: Cache的名称，具有唯一性，Ehcache会把该cache放到HashMap里。
maxEntriesLocalHeap:堆内存中最大缓存对象数，0没有限制
maxEntriesLocalDisk:磁盘中的最大对象数，默认为0不限制
eternal:设定缓存中elements是否永久有效，如果为true，timeouts设置将被忽略，element将永不过期；如果为false，则需要根据timeToIdleSeconds和timeToLiveSeconds相关配置进行判断。
overflowToDisk：内存中数据超过设定的内存限制，造成内存不足时， 是否启用磁盘缓存以将数据缓存到磁盘上。。
diskSpoolBufferSizeMB:设置DiskStore（磁盘缓存）的缓存区大小。默认是30MB。每个cache使用各自的DiskStore。
timeToIdleSeconds：缓存数据的钝化时间，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（即将eternal设为false时）， 如果该值是 0 就意味着元素可以停顿无穷长的时间，单位是秒。
timeToLiveSeconds：缓存数据的生存时间，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（即将eternal设为false时），如果该值是0就意味着元素可以停顿无穷长的时间，单位是秒。
memoryStoreEvictionPolicy：内存中数据超过设定的内存限制，造成内存不足时，该Cache启用的内存回收策略，默认值为LRU，可选FIFO、LFU。
Ehcache三大内存回收策略：
FIFO：First In First Out (先进先出)。
LFU： Less Frequently Used (最少被使用的)——所缓存的元素有一个hit属性，hit值最小的将会被“优先”清出缓存。
LRU：Least Recently Used(最近最少使用)——缓存的元素有一个时间戳，当缓存容量满了而又需要腾出地方来缓存新的元素时，那么现有缓存元素中时间戳离当前时间最远的元素将被“优先”清出缓存。
-->
<cache
name="PageEhCacheFilter"
maxEntriesLocalHeap="10000"
maxEntriesLocalDisk="1000"
eternal="false"
overflowToDisk="true"
diskSpoolBufferSizeMB="20"
timeToIdleSeconds="5"
timeToLiveSeconds="10"
memoryStoreEvictionPolicy="LFU" />
</ehcache>
ehcache.xsd
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified" version="1.7">
<xs:element name="ehcache">
<xs:complexType>
<xs:sequence>
<xs:element maxOccurs="1" minOccurs="0" ref="diskStore"/>
<xs:element maxOccurs="1" minOccurs="0" ref="sizeOfPolicy"/>
<xs:element maxOccurs="1" minOccurs="0" ref="transactionManagerLookup"/>
<xs:element maxOccurs="1" minOccurs="0" ref="cacheManagerEventListenerFactory"/>
<xs:element maxOccurs="1" minOccurs="0" ref="managementRESTService"/>
<xs:element maxOccurs="unbounded" minOccurs="0" ref="cacheManagerPeerProviderFactory"/>
<xs:element maxOccurs="unbounded" minOccurs="0" ref="cacheManagerPeerListenerFactory"/>
<xs:element maxOccurs="1" minOccurs="0" ref="terracottaConfig"/>
<xs:element maxOccurs= "1" minOccurs="0" ref="defaultCache"/>
<xs:element maxOccurs="unbounded" minOccurs="0" ref="cache"/>
</xs:sequence>
<xs:attribute name="name" use="optional"/>
<xs:attribute default="true" name="updateCheck" type="xs:boolean" use="optional"/>
<xs:attribute default="autodetect" name="monitoring" type="monitoringType" use="optional"/>
<xs:attribute default="true" name="dynamicConfig" type="xs:boolean" use="optional"/>
<xs:attribute default="15" name="defaultTransactionTimeoutInSeconds" type="xs:integer" use="optional"/>
<xs:attribute default="0" name="maxBytesLocalHeap" type="memoryUnitOrPercentage" use="optional"/>
<xs:attribute default="0" name="maxBytesLocalOffHeap" type="memoryUnit" use="optional"/>
<xs:attribute default="0" name="maxBytesLocalDisk" type="memoryUnit" use="optional"/>
</xs:complexType>
</xs:element>
<xs:element name="managementRESTService">
<xs:complexType>
<xs:attribute name="enabled" type="xs:boolean" use="optional"/>
<xs:attribute name="bind" use="optional"/>
<xs:attribute name="securityServiceLocation" use="optional"/>
<xs:attribute name="securityServiceTimeout" use="optional" type="xs:integer"/>
<xs:attribute name="sslEnabled" use="optional" type="xs:boolean"/>
<xs:attribute name="needClientAuth" use="optional" type="xs:boolean"/>
<xs:attribute name="sampleHistorySize" use="optional" type="xs:integer"/>
<xs:attribute name="sampleIntervalSeconds" use="optional" type="xs:integer"/>
<xs:attribute name="sampleSearchIntervalSeconds" use="optional" type="xs:integer"/>
</xs:complexType>
</xs:element>
<xs:element name="diskStore">
<xs:complexType>
<xs:attribute name="path" use="optional"/>
</xs:complexType>
</xs:element>
<xs:element name="transactionManagerLookup">
<xs:complexType>
<xs:attribute name="class" use="required"/>
<xs:attribute name="properties" use="optional"/>
<xs:attribute name="propertySeparator" use="optional"/>
</xs:complexType>
</xs:element>
<xs:element name="cacheManagerEventListenerFactory">
<xs:complexType>
<xs:attribute name="class" use="required"/>
<xs:attribute name="properties" use="optional"/>
<xs:attribute name="propertySeparator" use="optional"/>
</xs:complexType>
</xs:element>
<xs:element name="cacheManagerPeerProviderFactory">
<xs:complexType>
<xs:attribute name="class" use="required"/>
<xs:attribute name="properties" use="optional"/>
<xs:attribute name="propertySeparator" use="optional"/>
</xs:complexType>
</xs:element>
<xs:element name="cacheManagerPeerListenerFactory">
<xs:complexType>
<xs:attribute name="class" use="required"/>
<xs:attribute name="properties" use="optional"/>
<xs:attribute name="propertySeparator" use="optional"/>
</xs:complexType>
</xs:element>
<xs:element name="terracottaConfig">
<xs:complexType>
<xs:sequence>
<xs:element maxOccurs="1" minOccurs="0" name="tc-config">
<xs:complexType>
<xs:sequence>
<xs:any maxOccurs="unbounded" minOccurs="0" processContents="skip"/>
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:sequence>
<xs:attribute default="localhost:9510" name="url" use="optional"/>
<xs:attribute name="rejoin" type="xs:boolean" use="optional" default="false"/>
<xs:attribute name="wanEnabledTSA" type="xs:boolean" use="optional" default="false"/>
</xs:complexType>
</xs:element>
<!-- add clone support for addition of cacheExceptionHandler. Important! -->
<xs:element name="defaultCache">
<xs:complexType>
<xs:sequence>
<xs:element minOccurs="0" maxOccurs="unbounded" ref="cacheEventListenerFactory"/>
<xs:element minOccurs="0" maxOccurs="unbounded" ref="cacheExtensionFactory"/>
<xs:element minOccurs="0" maxOccurs="unbounded" ref="cacheLoaderFactory"/>
<xs:element minOccurs="0" maxOccurs="unbounded" ref="cacheDecoratorFactory"/>
<xs:element minOccurs="0" maxOccurs="1" ref="bootstrapCacheLoaderFactory"/>
<xs:element minOccurs="0" maxOccurs="1" ref="cacheExceptionHandlerFactory"/>
<xs:element minOccurs="0" maxOccurs="1" ref="pinning"/>
<xs:element minOccurs="0" maxOccurs="1" ref="terracotta"/>
<xs:element minOccurs="0" maxOccurs="1" ref="cacheWriter"/>
<xs:element minOccurs="0" maxOccurs="1" ref="copyStrategy"/>
<xs:element minOccurs="0" maxOccurs="1" ref="elementValueComparator"/>
<xs:element minOccurs="0" maxOccurs="1" ref="sizeOfPolicy"/>
<xs:element minOccurs="0" maxOccurs="1" ref="persistence"/>
</xs:sequence>
<xs:attribute name="diskExpiryThreadIntervalSeconds" type="xs:integer" use="optional"/>
<xs:attribute name="diskSpoolBufferSizeMB" type="xs:integer" use="optional"/>
<xs:attribute name="diskPersistent" type="xs:boolean" use="optional"/>
<xs:attribute name="diskAccessStripes" type="xs:integer" use="optional" default="1"/>
<xs:attribute name="eternal" type="xs:boolean" use="optional" default="false"/>
<xs:attribute name="maxElementsInMemory" type="xs:nonNegativeInteger" use="optional"/>
<xs:attribute name="maxEntriesLocalHeap" type="xs:nonNegativeInteger" use="optional"/>
<xs:attribute name="clearOnFlush" type="xs:boolean" use="optional"/>
<xs:attribute name="memoryStoreEvictionPolicy" type="xs:string" use="optional"/>
<xs:attribute name="overflowToDisk" type="xs:boolean" use="optional"/>
<xs:attribute name="timeToIdleSeconds" type="xs:nonNegativeInteger" use="optional"/>
<xs:attribute name="timeToLiveSeconds" type="xs:nonNegativeInteger" use="optional"/>
<xs:attribute name="maxElementsOnDisk" type="xs:nonNegativeInteger" use="optional"/>
<xs:attribute name="maxEntriesLocalDisk" type="xs:nonNegativeInteger" use="optional"/>
<xs:attribute name="transactionalMode" type="transactionalMode" use="optional" default="off"/>
<xs:attribute name="statistics" type="xs:boolean" use="optional" default="false"/>
<xs:attribute name="copyOnRead" type="xs:boolean" use="optional" default="false"/>
<xs:attribute name="copyOnWrite" type="xs:boolean" use="optional" default="false"/>
<xs:attribute name="cacheLoaderTimeoutMillis" type="xs:integer" use="optional" default="0"/>
<xs:attribute name="overflowToOffHeap" type="xs:boolean" use="optional" default="false"/>
<xs:attribute name="maxMemoryOffHeap" type="xs:string" use="optional"/>
</xs:complexType>
</xs:element>
<xs:element name="cache">
<xs:complexType>
<xs:sequence>
<xs:element minOccurs="0" maxOccurs="unbounded" ref="cacheEventListenerFactory"/>
<xs:element minOccurs="0" maxOccurs="unbounded" ref="cacheExtensionFactory"/>
<xs:element minOccurs="0" maxOccurs="unbounded" ref="cacheLoaderFactory"/>
<xs:element minOccurs="0" maxOccurs="unbounded" ref="cacheDecoratorFactory"/>
<xs:element minOccurs="0" maxOccurs="1" ref="bootstrapCacheLoaderFactory"/>
<xs:element minOccurs="0" maxOccurs="1" ref="cacheExceptionHandlerFactory"/>
<xs:element minOccurs="0" maxOccurs="1" ref="pinning"/>
<xs:element minOccurs="0" maxOccurs="1" ref="terracotta"/>
<xs:element minOccurs="0" maxOccurs="1" ref="cacheWriter"/>
<xs:element minOccurs="0" maxOccurs="1" ref="copyStrategy"/>
<xs:element minOccurs="0" maxOccurs="1" ref="searchable"/>
<xs:element minOccurs="0" maxOccurs="1" ref="elementValueComparator"/>
<xs:element minOccurs="0" maxOccurs="1" ref="sizeOfPolicy"/>
<xs:element minOccurs="0" maxOccurs="1" ref="persistence"/>
</xs:sequence>
<xs:attribute name="diskExpiryThreadIntervalSeconds" type="xs:integer" use="optional"/>
<xs:attribute name="diskSpoolBufferSizeMB" type="xs:integer" use="optional"/>
<xs:attribute name="diskPersistent" type="xs:boolean" use="optional"/>
<xs:attribute name="diskAccessStripes" type="xs:integer" use="optional" default="1"/>
<xs:attribute name="eternal" type="xs:boolean" use="optional" default="false"/>
<xs:attribute name="maxElementsInMemory" type="xs:nonNegativeInteger" use="optional"/>
<xs:attribute name="maxEntriesLocalHeap" type="xs:nonNegativeInteger" use="optional"/>
<xs:attribute name="memoryStoreEvictionPolicy" type="xs:string" use="optional"/>
<xs:attribute name="clearOnFlush" type="xs:boolean" use="optional"/>
<xs:attribute name="name" type="xs:string" use="required"/>
<xs:attribute name="overflowToDisk" type="xs:boolean" use="optional"/>
<xs:attribute name="timeToIdleSeconds" type="xs:nonNegativeInteger" use="optional"/>
<xs:attribute name="timeToLiveSeconds" type="xs:nonNegativeInteger" use="optional"/>
<xs:attribute name="maxElementsOnDisk" type="xs:nonNegativeInteger" use="optional"/>
<xs:attribute name="maxEntriesLocalDisk" type="xs:nonNegativeInteger" use="optional"/>
<xs:attribute name="maxEntriesInCache" type="xs:nonNegativeInteger" use="optional"/>
<xs:attribute name="transactionalMode" type="transactionalMode" use="optional" default="off" />
<xs:attribute name="statistics" type="xs:boolean" use="optional" default="false"/>
<xs:attribute name="copyOnRead" type="xs:boolean" use="optional" default="false"/>
<xs:attribute name="copyOnWrite" type="xs:boolean" use="optional" default="false"/>
<xs:attribute name="logging" type="xs:boolean" use="optional" default="false"/>
<xs:attribute name="cacheLoaderTimeoutMillis" type="xs:integer" use="optional" default="0"/>
<xs:attribute name="overflowToOffHeap" type="xs:boolean" use="optional" default="false"/>
<xs:attribute name="maxMemoryOffHeap" type="xs:string" use="optional"/>
<xs:attribute default="0" name="maxBytesLocalHeap" type="memoryUnitOrPercentage" use="optional"/>
<xs:attribute default="0" name="maxBytesLocalOffHeap" type="memoryUnitOrPercentage" use="optional"/>
<xs:attribute default="0" name="maxBytesLocalDisk" type="memoryUnitOrPercentage" use="optional"/>
</xs:complexType>
</xs:element>
<xs:element name="cacheEventListenerFactory">
<xs:complexType>
<xs:attribute name="class" use="required"/>
<xs:attribute name="properties" use="optional"/>
<xs:attribute name="propertySeparator" use="optional"/>
<xs:attribute name="listenFor" use="optional" type="notificationScope" default="all"/>
</xs:complexType>
</xs:element>
<xs:element name="bootstrapCacheLoaderFactory">
<xs:complexType>
<xs:attribute name="class" use="required"/>
<xs:attribute name="properties" use="optional"/>
<xs:attribute name="propertySeparator" use="optional"/>
</xs:complexType>
</xs:element>
<xs:element name="cacheExtensionFactory">
<xs:complexType>
<xs:attribute name="class" use="required"/>
<xs:attribute name="properties" use="optional"/>
<xs:attribute name="propertySeparator" use="optional"/>
</xs:complexType>
</xs:element>
<xs:element name="cacheExceptionHandlerFactory">
<xs:complexType>
<xs:attribute name="class" use="required"/>
<xs:attribute name="properties" use="optional"/>
<xs:attribute name="propertySeparator" use="optional"/>
</xs:complexType>
</xs:element>
<xs:element name="cacheLoaderFactory">
<xs:complexType>
<xs:attribute name="class" use="required"/>
<xs:attribute name="properties" use="optional"/>
<xs:attribute name="propertySeparator" use="optional"/>
</xs:complexType>
</xs:element>
<xs:element name="cacheDecoratorFactory">
<xs:complexType>
<xs:attribute name="class" use="required"/>
<xs:attribute name="properties" use="optional"/>
<xs:attribute name="propertySeparator" use="optional"/>
</xs:complexType>
</xs:element>
<xs:element name="searchAttribute">
<xs:complexType>
<xs:attribute name="name" use="required" type="xs:string" />
<xs:attribute name="expression" type="xs:string" />
<xs:attribute name="class" type="xs:string" />
<xs:attribute name="type" type="xs:string" use="optional"/>
<xs:attribute name="properties" use="optional" />
<xs:attribute name="propertySeparator" use="optional" />
</xs:complexType>
</xs:element>
<xs:element name="searchable">
<xs:complexType>
<xs:sequence>
<xs:element minOccurs="0" maxOccurs="unbounded" ref="searchAttribute"/>
</xs:sequence>
<xs:attribute name="keys" use="optional" type="xs:boolean" default="true"/>
<xs:attribute name="values" use="optional" type="xs:boolean" default="true"/>
<xs:attribute name="allowDynamicIndexing" use="optional" type="xs:boolean" default="false"/>
</xs:complexType>
</xs:element>
<xs:element name="pinning">
<xs:complexType>
<xs:attribute name="store" use="required" type="pinningStoreType"/>
</xs:complexType>
</xs:element>
<xs:element name="terracotta">
<xs:complexType>
<xs:sequence>
<xs:element minOccurs="0" maxOccurs="1" ref="nonstop"/>
</xs:sequence>
<xs:attribute name="clustered" use="optional" type="xs:boolean" default="true"/>
<xs:attribute name="coherentReads" use="optional" type="xs:boolean" default="true"/>
<xs:attribute name="localKeyCache" use="optional" type="xs:boolean" default="false"/>
<xs:attribute name="localKeyCacheSize" use="optional" type="xs:positiveInteger" default="300000"/>
<xs:attribute name="orphanEviction" use="optional" type="xs:boolean" default="true"/>
<xs:attribute name="orphanEvictionPeriod" use="optional" type="xs:positiveInteger" default="4"/>
<xs:attribute name="copyOnRead" use="optional" type="xs:boolean" default="false"/>
<xs:attribute name="coherent" use="optional" type="xs:boolean" default="false"/>
<xs:attribute name="consistency" use="optional" type="consistencyType" default="eventual"/>
<xs:attribute name="synchronousWrites" use="optional" type="xs:boolean" default="false"/>
<xs:attribute name="concurrency" use="optional" type="xs:nonNegativeInteger" default="0"/>
<xs:attribute name="localCacheEnabled" use="optional" type="xs:boolean" default="true"/>
<xs:attribute name="compressionEnabled" use="optional" type="xs:boolean" default="false"/>
</xs:complexType>
</xs:element>
<xs:simpleType name="consistencyType">
<xs:restriction base="xs:string">
<xs:enumeration value="strong" />
<xs:enumeration value="eventual" />
</xs:restriction>
</xs:simpleType>
<xs:element name="nonstop">
<xs:complexType>
<xs:sequence>
<xs:element minOccurs="0" maxOccurs="1" ref="timeoutBehavior"/>
</xs:sequence>
<xs:attribute name="enabled" use="optional" type="xs:boolean" default="true"/>
<xs:attribute name="immediateTimeout" use="optional" type="xs:boolean" default="false"/>
<xs:attribute name="timeoutMillis" use="optional" type="xs:positiveInteger" default="30000"/>
<xs:attribute name="searchTimeoutMillis" use="optional" type="xs:positiveInteger" default="30000"/>
</xs:complexType>
</xs:element>
<xs:element name="timeoutBehavior">
<xs:complexType>
<xs:attribute name="type" use="optional" type="timeoutBehaviorType" default="exception"/>
<xs:attribute name="properties" use="optional" default=""/>
<xs:attribute name="propertySeparator" use="optional" default=","/>
</xs:complexType>
</xs:element>
<xs:simpleType name="timeoutBehaviorType">
<xs:restriction base="xs:string">
<xs:enumeration value="noop" />
<xs:enumeration value="exception" />
<xs:enumeration value="localReads" />
<xs:enumeration value="localReadsAndExceptionOnWrite" />
</xs:restriction>
</xs:simpleType>
<xs:simpleType name="monitoringType">
<xs:restriction base="xs:string">
<xs:enumeration value="autodetect"/>
<xs:enumeration value="on"/>
<xs:enumeration value="off"/>
</xs:restriction>
</xs:simpleType>
<xs:simpleType name="pinningStoreType">
<xs:restriction base="xs:string">
<xs:enumeration value="localMemory" />
<xs:enumeration value="inCache" />
</xs:restriction>
</xs:simpleType>
<xs:simpleType name="terracottaCacheValueType">
<xs:restriction base="xs:string">
<xs:enumeration value="serialization" />
<xs:enumeration value="identity" />
</xs:restriction>
</xs:simpleType>
<xs:simpleType name="transactionalMode">
<xs:restriction base="xs:string">
<xs:enumeration value="off"/>
<xs:enumeration value="xa_strict"/>
<xs:enumeration value="xa"/>
<xs:enumeration value="local"/>
</xs:restriction>
</xs:simpleType>
<xs:element name="cacheWriter">
<xs:complexType>
<xs:sequence >
<xs:element minOccurs="0" maxOccurs="1" ref="cacheWriterFactory"/>
</xs:sequence>
<xs:attribute name="writeMode" use="optional" type="writeModeType" default="write-through"/>
<xs:attribute name="notifyListenersOnException" use="optional" type="xs:boolean" default="false"/>
<xs:attribute name="minWriteDelay" use="optional" type="xs:nonNegativeInteger" default="1"/>
<xs:attribute name="maxWriteDelay" use="optional" type="xs:nonNegativeInteger" default="1"/>
<xs:attribute name="rateLimitPerSecond" use="optional" type="xs:nonNegativeInteger" default="0"/>
<xs:attribute name="writeCoalescing" use="optional" type="xs:boolean" default="false"/>
<xs:attribute name="writeBatching" use="optional" type="xs:boolean" default="false"/>
<xs:attribute name="writeBatchSize" use="optional" type="xs:positiveInteger" default="1"/>
<xs:attribute name="retryAttempts" use="optional" type="xs:nonNegativeInteger" default="0"/>
<xs:attribute name="retryAttemptDelaySeconds" use="optional" type="xs:nonNegativeInteger" default="1"/>
<xs:attribute name="writeBehindConcurrency" use="optional" type="xs:nonNegativeInteger" default="1"/>
<xs:attribute name="writeBehindMaxQueueSize" use="optional" type="xs:nonNegativeInteger" default="0"/>
</xs:complexType>
</xs:element>
<xs:simpleType name="writeModeType">
<xs:restriction base="xs:string">
<xs:enumeration value="write-through" />
<xs:enumeration value="write-behind" />
</xs:restriction>
</xs:simpleType>
<xs:element name="cacheWriterFactory">
<xs:complexType>
<xs:attribute name="class" use="required"/>
<xs:attribute name="properties" use="optional"/>
<xs:attribute name="propertySeparator" use="optional"/>
</xs:complexType>
</xs:element>
<xs:element name="copyStrategy">
<xs:complexType>
<xs:attribute name="class" use="required" type="xs:string" />
</xs:complexType>
</xs:element>
<xs:element name="elementValueComparator">
<xs:complexType>
<xs:attribute name="class" use="required" type="xs:string" />
</xs:complexType>
</xs:element>
<xs:element name="sizeOfPolicy">
<xs:complexType>
<xs:attribute name="maxDepth" use="required" type="xs:integer" />
<xs:attribute name="maxDepthExceededBehavior" use="optional" default="continue" type="maxDepthExceededBehavior" />
</xs:complexType>
</xs:element>
<xs:element name="persistence">
<xs:complexType>
<xs:attribute name="strategy" use="required" type="persistenceStrategy"/>
<xs:attribute name="synchronousWrites" use="optional" default="false" type="xs:boolean"/>
</xs:complexType>
</xs:element>
<xs:simpleType name="persistenceStrategy">
<xs:restriction base="xs:string">
<xs:enumeration value="localTempSwap"/>
<xs:enumeration value="localRestartable"/>
<xs:enumeration value="none"/>
<xs:enumeration value="distributed"/>
</xs:restriction>
</xs:simpleType>
<xs:simpleType name="maxDepthExceededBehavior">
<xs:restriction base="xs:string">
<xs:enumeration value="continue"/>
<xs:enumeration value="abort"/>
</xs:restriction>
</xs:simpleType>
<xs:simpleType name="notificationScope">
<xs:restriction base="xs:string">
<xs:enumeration value="local"/>
<xs:enumeration value="remote"/>
<xs:enumeration value="all"/>
</xs:restriction>
</xs:simpleType>
<xs:simpleType name="memoryUnit">
<xs:restriction base="xs:token">
<xs:pattern value="[0-9]+[bBkKmMgG]?"/>
</xs:restriction>
</xs:simpleType>
<xs:simpleType name="memoryUnitOrPercentage">
<xs:restriction base="xs:token">
<xs:pattern value="([0-9]+[bBkKmMgG]?|100%|[0-9]{1,2}%)"/>
</xs:restriction>
</xs:simpleType>
</xs:schema>
4）编写过滤器：
package com.ghj.packageoffilter;
import java.util.Enumeration;
import javax.servlet.FilterChain;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import net.sf.ehcache.constructs.blocking.LockTimeoutException;
import net.sf.ehcache.constructs.web.AlreadyCommittedException;
import net.sf.ehcache.constructs.web.AlreadyGzippedException;
import net.sf.ehcache.constructs.web.filter.FilterNonReentrantException;
import net.sf.ehcache.constructs.web.filter.SimplePageCachingFilter;
import org.apache.commons.lang.StringUtils;
/**
* 页面缓存过滤器
* 页面缓存主要用Filter过滤器对请求的url进行过滤，如果该url在缓存中出现。那么页面数据就从缓存对象中获取，并以gzip压缩后返回。其速度是没有压缩缓存时速度的3-5倍，效率相当之高！
* 其中页面缓存的过滤器有CachingFilter，一般要扩展filter或是自定义Filter都继承该CachingFilter。
* SimplePageCachingFilter适用于缓存整个页面的情况，如果只需要缓存某一个片段，如使用jsp:include包含的部分，请使用SimplePageFragmentCachingFilter。
*/
public class PageEhCacheFilter extends SimplePageCachingFilter{
private static String[] cacheURLArray;
@Override
protected void doFilter(HttpServletRequest request, HttpServletResponse response, FilterChain chain)
throws AlreadyGzippedException, AlreadyCommittedException, FilterNonReentrantException,
LockTimeoutException, Exception {
if (cacheURLArray == null) {
String patterns = filterConfig.getInitParameter("patterns");
cacheURLArray = StringUtils.split(patterns, ",");
}
String requestURL = request.getRequestURL().toString();
boolean containCacheURLFlag = false;
if (cacheURLArray != null && cacheURLArray.length > 0) {
for (String cacheURL : cacheURLArray) {
System.out.println(cacheURL+" "+requestURL);
if (requestURL.contains(cacheURL.trim())) {//判断当前请求是否是要缓存的url
containCacheURLFlag = true;
break;
}
}
}
if (containCacheURLFlag) {//当前请求是要缓存的url
String queryString = request.getQueryString();
if (StringUtils.isNotEmpty(queryString)) {//当前请求含有采用问号传过来的参数
queryString = "?" + queryString;
System.out.println("当前请求被缓存：" + requestURL + queryString);
}else{
System.out.println("当前请求被缓存：" + requestURL);
}
super.doFilter(request, response, chain);
} else {//当前请求不是要缓存的url
chain.doFilter(request, response);
}
}
/**
* 重写acceptsGzipEncoding方法，使该过滤器兼容对客户使用IE6和IE7时发过来请求时的gzip压缩
* 使用Gzip压缩时，需注意两个问题：
* 1、Filter进行Gzip压缩时，采用系统默认编码方式，对于使用GBK编码的中文网页来说，需要将操作系统的语言设置为“zh_CN.GBK”，否则会出现乱码问题。
* 2、默认情况下CachingFilter类（SimplePageCachingFilter类的父类）会根据浏览器发送的请求头部所包含的Accept-Encoding参数值来判断是否进行Gzip压缩。虽然浏览器IE6和IE7支持Gzip压缩，但是在发送请求的时候却不带该参数，因此可以通过继承CachingFilter类，重写acceptsGzipEncoding方法来实现。
*/
@Override
protected boolean acceptsGzipEncoding(HttpServletRequest request) {
boolean ie6 = headerContains(request, "User-Agent", "MSIE 6.0");
boolean ie7 = headerContains(request, "User-Agent", "MSIE 7.0");
return acceptsEncoding(request, "gzip") || ie6 || ie7;
}
private boolean headerContains(final HttpServletRequest request, final String header, final String value) {
logRequestHeaders(request);
final Enumeration<?> accepted = request.getHeaders(header);
while (accepted.hasMoreElements()) {
final String headerValue = (String) accepted.nextElement();
if (headerValue.indexOf(value) != -1) {
return true;
}
}
return false;
}
}
5）编写jsp界面
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" import="java.util.Date,java.text.SimpleDateFormat"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>首页</title>
</head>
<body>
<div style="text-align:center;margin-top:360px;">
<font style="color:green;font-weight:bold;font-size: 18px"><%=new SimpleDateFormat("yyyy-MM-dd hh:MM:ss").format(new Date())%></font><br><br>
<font style="color:red;font-weight:bold;font-size: 27px">每次刷新页面，如果时间是变动的，则说明该页面没有被缓存或缓存已经过期，否则则说明该页面已经被缓存。</font>
</div>
</body>
</html>
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