OScache的使用

今天下午，想了好久，终于决定要用OSCache来缓存我的报表统计了，要不觉得效率很低。呵呵，当然我是选择了opensymphony的OSCache,它可以缓存任何Java对象以及JSP程序，以下是今天下午的成果，写了一个通用类，再在action里面缓存一下。试了一下，效果还算不错。

package com.finegold.digimus.comm;

import com.opensymphony.oscache.base.persistence.CachePersistenceException;

/**
 * @author 汪心利 2007-7-5
[email=*@copyRight]*@copyRight[/email] [url=http://www.finegold.com.cn/]WWW.FINEGOLD.COM.CN[/url]
*
*/
public interface Cache {
 /**
  * 根据key获取cache里的对象
  * 
  * @param key
  * @return
  * @throws CachePersistenceException
  */
 Object get(Object key) throws CachePersistenceException;

 /**
  * 根据key以及time获取cache里的对象，对应 inputOSCache(Object key, Object value, int
  * i)方法添加进去的对象
  * 
  * @param key
  * @param time
  * @return
  * @throws CachePersistenceException
  */
 Object get(Object key, int time) throws CachePersistenceException;

 /**
  * 将object添加cache
  * 
  * @param key
  * @param value
  * @throws CachePersistenceException
  */
 void inputOSCache(Object key, Object value)
   throws CachePersistenceException;

 /**
  * 将object添加cache
  * 
  * @param key
  * @param value
  * @param i
  * @throws CachePersistenceException
  */
 void inputOSCache(Object key, Object value, int i)
   throws CachePersistenceException;

 /**
  * 根据key删除object
  * 
  * @param key
  * @throws CachePersistenceException
  */
 void remove(Object key) throws CachePersistenceException;

 /**
  * 清空cache
  * 
  * @throws CachePersistenceException
  */
 void clear() throws CachePersistenceException;

 /**
  * 销毁cache
  * 
  * @throws CachePersistenceException
  */
 void destroy() throws CachePersistenceException;

 /**
  * 根据time 获取key
  * 
  * @param time
  * @return
  * @throws CachePersistenceException
  */
 Object getkey(int time) throws CachePersistenceException;
}

接口的实现类：

package com.finegold.digimus.comm;

/**
 * @author BlueSKy_itwangxinli 2007-7-5 [email=*@copyRight]
*@copyRight[/email] [url=http://www.finegold.com.cn/]WWW.FINEGOLD.COM.CN[/url]
 */
import java.util.Properties;

import org.apache.commons.lang.RandomStringUtils;

import com.opensymphony.oscache.base.EntryRefreshPolicy;
import com.opensymphony.oscache.base.NeedsRefreshException;
import com.opensymphony.oscache.base.persistence.CachePersistenceException;
import com.opensymphony.oscache.general.GeneralCacheAdministrator;
import com.opensymphony.oscache.web.filter.ExpiresRefreshPolicy;

/**
 * OSCache 缓存共用类
 * 
 * @author 汪心利 2007-7-5
 */
public class OSCache implements Cache {
 /**
  * 通用缓存管理类 administrator
  */
 private GeneralCacheAdministrator cache;

 private static OSCache instance;

 public OSCache() {
  this.cache = new GeneralCacheAdministrator();
 }

 /**
  * 指定加载加载cache.propeties fiel 默认情况下加载classes目录下的OScache.properties
  * 
  * @param prop
  */
 public OSCache(Properties prop) {
  this.cache = new GeneralCacheAdministrator(prop);
 }

 /**
  * 返回OSCache 的Instance 单态模式
  * 
  * @return
  */
 public synchronized static OSCache getInstance() {

  if (instance == null) {
   instance = new OSCache();
  }
  return instance;
 }

 /**
  * 设置缓存容量 default value 请查看oscache配置文件，OSCache系统本身默认值unlimited
  * 
  * @param cacheCapacity
  */
 public void setCacheCapacity(int cacheCapacity) {
  this.cache.setCacheCapacity(cacheCapacity);
 }

 /**
  * 根据Key获取cache里缓存的object
  * 
  * @param key
  *            查找关键字
  */
 public Object get(Object key) throws CachePersistenceException {
  try {
   return this.cache.getFromCache(String.valueOf(key));
  } catch (NeedsRefreshException e) {
   cache.cancelUpdate(String.valueOf(key));
   return null;
  }
 }

 /**
  * 根据key和time获取缓存的object
  * 
  * @param key
  *            查找的key
  * @param time
  *            (最准确的含义-->)How long the object can stay in cache in seconds
  */
 public Object get(Object key, int time) throws CachePersistenceException {
  try {
   return this.cache.getFromCache(String.valueOf(key), time);
  } catch (NeedsRefreshException e) {
   cache.cancelUpdate(String.valueOf(key));
   return null;
  }
 }

 /**
  * 尽量不要使用该方法 根据time 获取key
  * 
  * @param time
  *            时间
  */
 public Object getkey(int time) throws CachePersistenceException {
  String key = RandomStringUtils.randomAlphanumeric(10);
  try {
   while (this.cache.getFromCache(key) != null) {
    key = RandomStringUtils.randomAlphanumeric(10);
   }
   return key;
  } catch (NeedsRefreshException e) {
   return key;
  }
 }

 /**
  * 缓存对象
  */
 public void inputOSCache(Object key, Object value)
   throws CachePersistenceException {
  this.cache.putInCache(String.valueOf(key), value);
 }

 /**
  * 缓存对象
  * 
  * @param key
  *            缓存对象的key
  * @param value
  *            缓存对象的value
  * @param n
  *            缓存对象有效时间
  */
 public void inputOSCache(Object key, Object value, int n)
   throws CachePersistenceException {
  EntryRefreshPolicy Policy = new ExpiresRefreshPolicy(n);
  this.cache.putInCache(String.valueOf(key), value, Policy);
 }

 /**
  * 根据key从cache里 删除object
  * 
  * @param 要删除缓存对象的key
  */
 public void remove(Object key) throws CachePersistenceException {
  this.cache.flushEntry(String.valueOf(key));
 }

 /**
  * 清空所有的缓存
  */
 public void clear() throws CachePersistenceException {
  this.cache.flushAll();
 }

 /**
  * 销毁缓存
  */
 public void destroy() throws CachePersistenceException {
  this.cache.destroy();
 }
}

配置web.xml

      CacheFilter
com.opensymphony.oscache.web.filter.CacheFilter
 
         time
         600
      
      
         scope
         session