EhCache缓存页面、局部页面和对象缓存


页面缓存:SimplePageCachingFilter

web.xml


  <filter>
    <filter-name>PageEhCacheFilterfilter-name>
    <filter-class>net.sf.ehcache.constructs.web.filter.SimplePageCachingFilterfilter-class>
  filter>
  <filter-mapping>
    <filter-name>PageEhCacheFilterfilter-name>
    
    <url-pattern>/userHomeurl-pattern>
  filter-mapping>
ehcache.xml(放在classpath路径下) 
<?xml version="1.0" encoding="UTF-8"?>
<ehcache>
    
    <cache name="SimplePageCachingFilter"
           maxElementsInMemory="10"
           maxElementsOnDisk="10"
           overflowToDisk="true"
           diskSpoolBufferSizeMB="20"
           timeToIdleSeconds="7"
           timeToLiveSeconds="10"
           memoryStoreEvictionPolicy="LFU"
    />
ehcache>
SimpleCachingHeadersPageCachingFilter与使用SimplePageCachingFilter几乎是一样的。所不同的是前者在构建返回信息的时候会设置“Last-Modified、Expires、Cache-Control、ETag”这四个缓存头信息,如果在设置之前这些信息已经存在的话,那么它们将会被忽略,而直接使用SimpleCachingHeadersPageCachingFilter重新生成过的。


局部页面缓存:SimplePageFragmentCachingFilter

(页面局部片段,例如包含的部分必要配置<dispatcher>INCLUDEdispatcher>

   
web.xml

  <filter>
    <filter-name>PageEhCacheFilterfilter-name>
    <filter-class>net.sf.ehcache.constructs.web.filter.SimplePageFragmentCachingFilterfilter-class>
  filter>
  <filter-mapping>
    <filter-name>PageEhCacheFilterfilter-name>
    <url-pattern>/head.jspurl-pattern>
    
    <dispatcher>INCLUDEdispatcher>
  filter-mapping>
ehcache.xml
<?xml version="1.0" encoding="UTF-8"?>
<ehcache>
    
    <cache name="SimplePageFragmentCachingFilter"
           maxElementsInMemory="10"
           maxElementsOnDisk="10"
           overflowToDisk="true"
           diskSpoolBufferSizeMB="20"
           timeToIdleSeconds="7"
           timeToLiveSeconds="10"
           memoryStoreEvictionPolicy="LFU"
    />
ehcache>
我们include的jsp页面在filter中要指定INCLUDE,如果没有指定任何< dispatcher >元素,默认值是REQUEST就不会拦截了;如果指定了INCLUDE,则过滤器只过滤通过include过来的请求,而不会过滤直接从客户端过来的请求。  
 这个元素有四个可能的值:即REQUEST,FORWARD,INCLUDE和ERROR,可以在一个元素中加入任意数目的,使得filter将会作用于直接从客户端过来的request,通过forward过来的request,通过include过来的request和通过过来的request。如果没有指定任何元素,默认值是REQUEST。
  需要jar包:ehcache-web-2.0.4.jar
对象缓存: 方法一:net.sf.ehcache.CacheManager
public void test() {
    net.sf.ehcache.CacheManager cacheManager = CacheManager.create();
    net.sf.ehcache.Cache cache = cacheManager.getCache("SimplePageCachingFilter");
    cache.put(new Element("key", "value"));  //设置缓存
    cache.get("key").getValue();  //查询缓存
}

方法二:org.springframework.cache.CacheManager(spring集成EhCache)


spring的缓存配置bean

    <bean id="ehCacheManagerFactory" class="org.springframework.cache.ehcache.EhCacheManagerFactoryBean">
        <property name="configLocation" value="classpath:ehcache.xml" />
    bean>
    <bean id="cacheManager" class="org.springframework.cache.ehcache.EhCacheCacheManager">  
        <property name="cacheManager" ref="ehCacheManagerFactory"/>
    bean>
使用缓存
 @Autowired
    private org.springframework.cache.CacheManager cacheManager;
    //private net.sf.ehcache.CacheManager  //这里也可以用原生的CacheManager,注入时强制转换类型
    public void test() {
        org.springframework.cache.Cache cache = cacheManager.getCache("SimplePageCachingFilter");
        cache.put("key", "value");  //设置缓存
        cache.get("key").get();  //查询缓存
        //输出 value
    }

需要jar包:ehcache-core-2.4.3.jar


 

方法注解缓存


方法一:使用 org.springframework.cache.annotation.Cacheable注解缓存   spring的缓存配置bean
    
    <cache:annotation-driven cache-manager="cacheManager" /> 
    <bean id="ehCacheManagerFactory" class="org.springframework.cache.ehcache.EhCacheManagerFactoryBean">
        <property name="configLocation" value="classpath:ehcache.xml" />
    bean>
    <bean id="cacheManager" class="org.springframework.cache.ehcache.EhCacheCacheManager">  
        <property name="cacheManager" ref="ehCacheManagerFactory"/>
    bean>

 使用注解缓存 Annotation

    import org.springframework.cache.annotation.Cacheable;
    @Cacheable(value = "SimplePageCachingFilter")
    //SimplePageCachingFilter为ehcache.xml上配的名字,不同的参数name使用的缓存不一样
    public String getData(String name) {
        SimpleDateFormat format = new SimpleDateFormat("HH:mm:ss");
        System.out.println(name);
        return format.format(new Date());
    }

(更多spring缓存注解“CachePut更新缓存”、“CacheEvict清除缓存”的具体用法可自行百度)

  方法二:使用ehcache-spring-annotations开启ehcache的注解功能 spring的缓存配置bean,注意下面cache-manager参数值与上面的区别
    命名空间 xmlns:ehcache="http://ehcache-spring-annotations.googlecode.com/svn/schema/ehcache-spring"  
       xsi:schemaLocation= http://ehcache-spring-annotations.googlecode.com/svn/schema/ehcache-spring
       http://ehcache-spring-annotations.googlecode.com/svn/schema/ehcache-spring/ehcache-spring-1.1.xsd
 
    
    <ehcache:annotation-driven cache-manager="ehCacheManagerFactory" /> 
    <bean id="ehCacheManagerFactory" class="org.springframework.cache.ehcache.EhCacheManagerFactoryBean">
        <property name="configLocation" value="classpath:ehcache.xml" />
    bean>
使用注解缓存 Annotation
    import com.googlecode.ehcache.annotations.Cacheable;
    @Cacheable(cacheName = "SimplePageCachingFilter")
    //SimplePageCachingFilter为ehcache.xml上配的名字,不同的参数name使用的缓存不一样
    public String getData(String name) {
        SimpleDateFormat format = new SimpleDateFormat("HH:mm:ss");
        System.out.println(name);
        return format.format(new Date());
    }


(更多注解“TriggersRemove清除缓存”的具体用法可自行百度)

  需要jar包:ehcache-spring-annotations-1.2.0.jar、guava-r09.jar