基于memcached的SNA实现(1)

系统要集群，使用SNA方案。
一、 缓存的处理
缓存要使用统一的缓存服务器，集中式缓存。
原先的实现采用ehcache。
在spring里的配置，以资源缓存为例：

<!-- EhCache Manager -->
    <bean id="cacheManager" class="org.springframework.cache.ehcache.EhCacheManagerFactoryBean">
        <property name="configLocation">
            <value>classpath:ehcache.xml</value>
        </property>
</bean>

<bean id="resourceCacheBackend"
           class="org.springframework.cache.ehcache.EhCacheFactoryBean">
        <property name="cacheManager" ref="cacheManager"/>
        <property name="cacheName" value="resourceCache"/>
    </bean>

    <bean id="resourceCache"
           class="com.framework.extcomponent.security.authentication.services.acegi.cache.EhCacheBasedResourceCache"
           autowire="byName">
        <property name="cache" ref="resourceCacheBackend"/>
    </bean>

cacheManager负责对ehcache进行管理，初始化、启动、停止。
resourceCacheBackend负责实际执行缓存操作，put 、get、remove。
resourceCache实现具有业务语义的业务应用层面的缓存操作，内部调用resourceCacheBackend操作。

现在采用memcached。
关于客户端，采用文初封装的客户端，地址在http://code.google.com/p/memcache-client-forjava/。
使用spring的FactoryBean进行二次封装。同理：
memcachedManager负责对memcached进行管理，初始化、启动、停止。
代码：

/**
* User: ronghao
* Date: 2008-10-14
* Time: 10:36:30
* 管理Memcached 的CacheManager
*/
public class MemcachedCacheManagerFactoryBean implements FactoryBean, InitializingBean, DisposableBean {

    protected final Log logger = LogFactory.getLog(getClass());

    private ICacheManager<IMemcachedCache> cacheManager;

    public Object getObject() throws Exception {
        return cacheManager;
     }

    public Class getObjectType() {
        return this.cacheManager.getClass();
     }

    public boolean isSingleton() {
        return true;
     }

    public void afterPropertiesSet() throws Exception {
         logger.info("Initializing Memcached CacheManager");
         cacheManager = CacheUtil.getCacheManager(IMemcachedCache.class,
                 MemcachedCacheManager.class.getName());
         cacheManager.start();
     }

    public void destroy() throws Exception {
         logger.info("Shutting down Memcached CacheManager");
         cacheManager.stop();
     }
}

配置：

<bean id="memcachedManager"
           class="com.framework.extcomponent.cache.MemcachedCacheManagerFactoryBean"/>

resourceCacheBackend负责实际执行缓存操作，put 、get、remove。
代码：

/**
* User: ronghao
* Date: 2008-10-14
* Time: 10:37:16
* 返回   MemcachedCache
*/
public class MemcachedCacheFactoryBean implements FactoryBean, BeanNameAware, InitializingBean {

    protected final Log logger = LogFactory.getLog(getClass());

    private ICacheManager<IMemcachedCache> cacheManager;
    private String cacheName;
    private String beanName;
    private IMemcachedCache cache;

    public void setCacheManager(ICacheManager<IMemcachedCache> cacheManager) {
        this.cacheManager = cacheManager;
     }

    public void setCacheName(String cacheName) {
        this.cacheName = cacheName;
     }

    public Object getObject() throws Exception {
        return cache;
     }

    public Class getObjectType() {
        return this.cache.getClass();
     }

    public boolean isSingleton() {
        return true;
     }

    public void setBeanName(String name) {
        this.beanName=name;
     }

    public void afterPropertiesSet() throws Exception {
        // If no cache name given, use bean name as cache name.
       if (this.cacheName == null) {
        this.cacheName = this.beanName;
     }
         cache = cacheManager.getCache(cacheName);
     }
}

配置：

<bean id="resourceCacheBackend"
           class="com.framework.extcomponent.cache.MemcachedCacheFactoryBean">
        <property name="cacheManager" ref="memcachedManager"/>
        <property name="cacheName" value="memcache"/>
    </bean>

resourceCache同上，替换新的实现类MemcachedBasedResourceCache即可。