cache对策(一)基类

cache策略(一)基类
cache策略(一)基类
这个设计策略参考了很多同事的代码
cache的配置文件applicationContext-cache.xml如下：
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">
<beans>
<bean id="cacheManager"
   />
     </entry>
     <entry key="HASHMAPCACHE">
      <ref local="hashMapCacheProvider" />
     </entry>
     <entry key="MEMCACHE">
      <ref local="memCacheProvider" />
     </entry>
    </map>
   </property>
</bean>

<!-- 定义 oscache 的提供类 -->
<bean id="osCacheProvider"
   init-method="start"/>

<!-- 定义 hashMapcache 的提供类 -->
<bean id="hashMapCacheProvider"
   init-method="start"/>

<!-- 定义 memcached 的提供类 -->
<bean id="memCacheProvider"
   init-method="start"/>
</beans>

其中比较重要的是CacheManagerImpl.java，它可以选择用不同的实现去做缓存，
以后如果要新加入一个cache的类型，也只是增加一个provider而已
CacheManagerImpl.java如下：
package com.sillycat.easyview.plugin.cache.base;

import java.util.Map;
import java.util.Properties;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import com.sillycat.easyview.plugin.cache.CacheManager;
import com.sillycat.easyview.plugin.commons.exceptions.CacheException;

/**
* 用某种策略新建一个CACHE，具体的CACHE建立使用具体的CACHE PROVIDE BUILDER类。
*/
public final class CacheManagerImpl implements CacheManager {
private static final Log log = LogFactory.getLog(CacheManagerImpl.class);

// 不同种CACHE提供的CACHE实始化实现?????CACHE????CACHE???????
private Map cacheProviders;

private CacheManagerImpl() {
}

// 通常的CACHE提供以下四种的CACHE策略，性能以 READ_ONLY 为最高???
public static final String READ_ONLY = "READ_ONLY";
public static final String READ_WRITE = "READ_WRITE"; // read-write
public static final String NONSTRICT_READ_WRITE = "NONSTRICT_READ_WRITE"; // nonstrict-read-write
public static final String TRANSACTIONAL = "TRANSACTIONAL"; // transactional

public BaseCache createNewCache(final String concurrencyStrategy,
    String cacheProvider, String regionName)
    throws CacheException {
   BaseCache cacheStractegy = null;

   // 创建cache策略类
   if (concurrencyStrategy.equals(READ_ONLY)) {
    cacheStractegy = new ReadOnlyCache();
   }
   // 创建实际的cache
   CacheProvider provider = (CacheProvider) cacheProviders
     .get(cacheProvider);
   Cache cache = provider.buildCache(regionName);

   cacheStractegy.setCache(cache);
   return cacheStractegy;
}

/**
* 设置cache提供者列表
*/
public Map getCacheProviders() {
   return cacheProviders;
}

public void setCacheProviders(Map cacheProviders) {
   this.cacheProviders = cacheProviders;
}
}

使用时只需要选择不同的provider就可以了，测试用例CacheManagerTest.java如下：
package com.sillycat.easyview.plugin.cache;

import com.sillycat.easyview.core.model.User;
import com.sillycat.easyview.plugin.cache.base.BaseCache;
import com.sillycat.easyview.plugin.cache.base.Cache;
import com.sillycat.easyview.plugin.cache.base.CacheManagerImpl;
import com.sillycat.easyview.plugin.commons.base.ServiceTestBase;
import com.sillycat.easyview.plugin.commons.exceptions.CacheException;

public class CacheManagerTest extends ServiceTestBase {

private CacheManager cacheManager;

protected void setUp() throws Exception {
   super.setUp();
   cacheManager = (CacheManager) appContext.getBean("cacheManager");
}

protected void tearDown() throws Exception {
   super.tearDown();

}

public void testDumy() {
   assertTrue(true);
}

public void testOSCache() {
   BaseCache baseCache = null;
   try {
    baseCache = cacheManager.createNewCache(CacheManagerImpl.READ_ONLY,
      "OSCACHE", "www.sillycat.com");
   } catch (CacheException e) {
    e.printStackTrace();
   }
   User u = new User();
   u.setId(new Integer("1234"));
   u.setLogonName("sillycat");
   u.setEmail("magic_dreamer@126.com");

   Cache cache = baseCache.getCache();
   try {
    cache.put(u.getId(), u);
    User t = (User) cache.get(u.getId());
    System.out.println(t.getLogonName());
    System.out.println(t.getEmail());
   } catch (CacheException e) {
    e.printStackTrace();
   }
}
}