using springmodules-cache

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        项目进入了后期阶段，发现了不少的性能问题，其中有部分领域对象在应用的某些阶段相对稳定，于是准备采用cache，减少对象构建次数，减少数据库访问次数，有针对性地改善性能问题。

       using springmodules-cache的主要原因是其屏蔽了各个不同cache产品的接口差异性，提供了一致的编程模型，已经实现adapter的包括： EHCache, JBoss Cache, Java Caching System (JCS) and OSCache。

        由于我们的项目已经使用了spring2.0，要引入oscache，需要做的工作如下：

1.  需要的jar包括：jgroups-all.jar,oscache-2.3.2.jar,spring-modules-cache.jar,spring.jar,commons-logging.jar,jakarta-oro.jar.
2. 增加了ArgumentsCacheKeyGenerator类,实现org.springmodules.cache.key.CacheKeyGenerator接口。不使用sm自带的hashcodecachekeygenerator原因是，想自己能够在其它模块手动生成cacheKey，以便主动refresh cache。

   java 代码

   import java.io.Serializable;
   
   import org.aopalliance.intercept.MethodInvocation;
   import org.springmodules.cache.key.CacheKeyGenerator;
   
   public class ArgumentsCacheKeyGenerator implements CacheKeyGenerator {
   
       private String prefix="";
   
       public Serializable generateKey(MethodInvocation mi) {
           // TODO Auto-generated method stub
           StringBuffer sb = new StringBuffer();
           sb.append(this.getPrefix()).append('_');
           Object[] args = mi.getArguments();
           for( int i=0; i
               sb.append(args[i]);
           }
           return sb.toString();
       }
   
       public String getPrefix() {
           return prefix;
       }
   
       public void setPrefix(String prefix) {
           this.prefix = prefix;
       }
   
   }

3. 增加了oscache_config.properties，cache容量为100个对象，调度算法为LRU。

   java 代码

   # CACHE ALGORITHM
   #
   # Default cache algorithm to use. Note that in order to use an algorithm
   # the cache size must also be specified. If the cache size is not specified,
   # the cache algorithm will be Unlimited cache.
   #
   cache.algorithm=com.opensymphony.oscache.base.algorithm.LRUCache
   # cache.algorithm=com.opensymphony.oscache.base.algorithm.FIFOCache
   # cache.algorithm=com.opensymphony.oscache.base.algorithm.UnlimitedCache
   
   # CACHE SIZE
   #
   # Default cache size in number of items. If a size is specified but not
   # an algorithm, the cache algorithm used will be LRUCache.
   #
   cache.capacity=100
   
   
   # CACHE IN MEMORY
   #
   # If you want to disable memory caching, just uncomment this line.
   #
   # cache.memory=false
   
   
   # CACHE KEY
   #
   # This is the key that will be used to store the cache in the application
   # and session scope.
   #
   # If you want to set the cache key to anything other than the default
   # uncomment this line and change the cache.key
   #
   # cache.key=__oscache_cache
   
   
   # USE HOST DOMAIN NAME IN KEY
   #
   # Servers for multiple host domains may wish to add host name info to
   # the generation of the key.  If this is true, then uncomment the
   # following line.
   #
   # cache.use.host.domain.in.key=true
   
   
   # CACHE LISTENERS
   #
   # These hook OSCache events and perform various actions such as logging
   # cache hits and misses, or broadcasting to other cache instances across a cluster.
   # See the documentation for further information.
   #
   # cache.event.listeners=com.opensymphony.oscache.plugins.clustersupport.JMSBroadcastingListener,  \
   #                       com.opensymphony.oscache.extra.CacheEntryEventListenerImpl,               \
   #                       com.opensymphony.oscache.extra.CacheMapAccessEventListenerImpl,           \
   #                       com.opensymphony.oscache.extra.ScopeEventListenerImpl
   
   
   # CACHE PERSISTENCE CLASS
   #
   # Specify the class to use for persistence. If you use the supplied DiskPersistenceListener,
   # don't forget to supply the cache.path property to specify the location of the cache
   # directory.
   #
   # If a persistence class is not specified, OSCache will use memory caching only.
   #
   # cache.persistence.class=com.opensymphony.oscache.plugins.diskpersistence.DiskPersistenceListener
   
   # CACHE OVERFLOW PERSISTENCE
   # Use persistent cache in overflow or not. The default value is false, which means
   # the persistent cache will be used at all times for every entry.  true is the recommended setting.
   #
   # cache.persistence.overflow.only=true
   
   # CACHE DIRECTORY
   #
   # This is the directory on disk where caches will be stored by the DiskPersistenceListener.
   # it will be created if it doesn't already exist. Remember that OSCache must have
   # write permission to this directory.
   #
   # Note: for Windows machines, this needs \ to be escaped
   # ie Windows:
   # cache.path=c:\\myapp\\cache
   # or *ix:
   # cache.path=/opt/myapp/cache
   #
   # cache.path=c:\\app\\cache
   
   
   # THREAD BLOCKING BEHAVIOR
   #
   # When a request is made for a stale cache entry, it is possible that another thread is already
   # in the process of rebuilding that entry. This setting specifies how OSCache handles the
   # subsequent 'non-building' threads. The default behaviour (cache.blocking=false) is to serve
   # the old content to subsequent threads until the cache entry has been updated. This provides
   # the best performance (at the cost of serving slightly stale data). When blocking is enabled,
   # threads will instead block until the new cache entry is ready to be served. Once the new entry
   # is put in the cache the blocked threads will be restarted and given the new entry.
   # Note that even if blocking is disabled, when there is no stale data available to be served
   # threads will block until the data is added to the cache by the thread that is responsible
   # for building the data.
   #
   # cache.blocking=false
   
   
   
   # CACHE UNLIMITED DISK
   # Use unlimited disk cache or not. The default value is false, which means
   # the disk cache will be limited in size to the value specified by cache.capacity.
   #
   # cache.unlimited.disk=false
   
   
   # JMS CLUSTER PROPERTIES
   #
   # Configuration properties for JMS clustering. See the clustering documentation
   # for more information on these settings.
   #
   #cache.cluster.jms.topic.factory=java:comp/env/jms/TopicConnectionFactory
   #cache.cluster.jms.topic.name=java:comp/env/jms/OSCacheTopic
   #cache.cluster.jms.node.name=node1
   
   
   # JAVAGROUPS CLUSTER PROPERTIES
   #
   # Configuration properites for the JavaGroups clustering. Only one of these
   # should be specified. Default values (as shown below) will be used if niether
   # property is set. See the clustering documentation and the JavaGroups project
   # (www.javagroups.com) for more information on these settings.
   #
   #cache.cluster.properties=UDP(mcast_addr=231.12.21.132;mcast_port=45566;ip_ttl=32;\
   #mcast_send_buf_size=150000;mcast_recv_buf_size=80000):\
   #PING(timeout=2000;num_initial_members=3):\
   #MERGE2(min_interval=5000;max_interval=10000):\
   #FD_SOCK:VERIFY_SUSPECT(timeout=1500):\
   #pbcast.NAKACK(gc_lag=50;retransmit_timeout=300,600,1200,2400,4800;max_xmit_size=8192):\
   #UNICAST(timeout=300,600,1200,2400):\
   #pbcast.STABLE(desired_avg_gossip=20000):\
   #FRAG(frag_size=8096;down_thread=false;up_thread=false):\
   #pbcast.GMS(join_timeout=5000;join_retry_timeout=2000;shun=false;print_local_addr=true)
   #cache.cluster.multicast.ip=231.12.21.132

4. 增加了cacheContext.xml，spirng中cache的配置文件.

   xml 代码

   
   
        class="org.springmodules.cache.provider.oscache.OsCacheManagerFactoryBean">                  <bean id="cacheProviderFacade"
           class="org.springmodules.cache.provider.oscache.OsCacheFacade">
           <property name="cacheManager" ref="cacheManager" />
      bean>
   
       <bean id="chinatechKeyGenerator" class="cache.key.ArgumentsCacheKeyGenerator" >
           <property name="prefix">
               <value>CHINATECHvalue>
         property>
      bean>

5. 修改applicationContext.xml

   xml 代码

   <bean id="tc2"
       class="org.springmodules.cache.interceptor.proxy.CacheProxyFactoryBean">
       <property name="cacheProviderFacade" ref="cacheProviderFacade" />
       <property name="cacheKeyGenerator" ref="chinatechKeyGenerator" />
       <property name="cachingModels">
           <props>
               <prop key="get*">refreshPeriod=600;groups=CHINATECHprop>
           props>
       property>
       <property name="flushingModels">
           <props>
               <prop key="update*">groups=CHINATECHprop>
           props>
       property>
   
       <property name="target" ref="tc2Target" />
   bean>

6. 修改web.xml，增加cacheContext.xml初始化spring配置。

 springmodules站点：springmodules.dev.java.net/

oscache站点：www.opensymphony.com/oscache

• mytest.rar (7.8 KB)
• 描述: 上面都是说实际的项目，附件是一个java application的例子，供学习。TestCache测试源程序。需要自己下载需要的jar包。
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