hibernate-memcached--在Hibernate中使用Memcached作为一个二级分布式缓存
官方网址:http://code.google.com/p/hibernate-memcached/
目前最新版本为1.0,支持Hibernate3.3.
下面是具体的使用方法:
hibernate-memcached需要支持的类库如下:
hibernate-memcached-<version>.jarmemcached-2.1.jarspy-2.4.jarcommons-codec1.3slf4j-1.5.0.jar如果你的项目使用的是Log4j,可以用slf4j-log4j12-1.5.0.jar
配置方法如下：
配置Hibernate使用cache提供类
hibernate.cache.provider_classcom.googlecode.hibernate.memcached.MemcachedCacheProvider
设置查询缓存开启
| hibernate.cache.use_query_cache | true |
其它一些参数设置说明:PropertyDefaultDescriptionhibernate.memcached.serverslocalhost:11211memcached服务地址，多个用空格分隔
格式host:port
建议不要开启。
配置示例(本文以Hibernate3.3-entitymanager为例)
配置persistence.xml文件
<persistencexmlns="http://java.sun.com/xml/ns/persistence""target="_new">http://java.sun.com/xml/ns/persistence"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://java.sun.com/xml/ns/persistencehttp://java.sun.com/xml/ns/persistence/persistence_1_0.xsd"version="1.0">
<persistence-unitname="entityManager"transaction-type="RESOURCE_LOCAL">
<provider>org.hibernate.ejb.HibernatePersistence</provider>
<jta-data-source>java:comp/env/jdbc/qualitydb</jta-data-source>
<properties>
<propertyname="hibernate.dialect"value="org.hibernate.dialect.PostgreSQLDialect"/>
<propertyname="hibernate.max_fetch_depth"value="3"/>
<propertyname="hibernate.show_sql"value="true"/>
<propertyname="hibernate.cache.region_prefix"value="quality.cache.ehcache"/>
<propertyname="hibernate.cache.use_second_level_cache"value="true"/>
<propertyname="hibernate.cache.use_structured_entries"value="true"/>
<propertyname="hibernate.cache.use_query_cache"value="true"/>
<propertyname="hibernate.cache.provider_class"value="com.googlecode.hibernate.memcached.MemcachedCacheProvider"/>
<propertyname="hibernate.memcached.servers"value="localhost:11211"/>
</properties>
</persistence-unit>
</persistence>
启动后，提示如下：
2008-08-2817:10:08,312JCLLoggerAdapter.java265INFO--StartingMemcachedClient...
2008-08-2817:10:08.718INFOnet.spy.memcached.MemcachedConnection:Added{QAsa=localhost/127.0.0.1:11211,#Rops=0,#Wops=0,#iq=0,topRop=null,topWop=null,toWrite=0,interested=0}toconnectqueue
2008-08-2817:10:08.750INFOnet.spy.memcached.MemcachedConnection:Connectionstatechangedforsun.nio.ch.SelectionKeyImpl@16e59da
表示我们第一步配置已经成功了，接下来，对需要进行缓存的Entity进行配置
2@Cache(usage=CacheConcurrencyStrategy.READ_WRITE)//设置要求缓存
3publicclassStudent{
4
5@Id
6@Column(length=32)
7privateStringid;
8
9@Column(length=20)
10privatestringname;
11
12@OneToMany
13@Cache(usage=CacheConcurrencyStrategy.READ_WRITE)
14privateSet<Book>books;
15
16}