java简单的缓存
import java.util.Date;import java.util.HashMap;import java.util.HashSet;import java.util.Iterator;import java.util.Map;import java.util.Set;public class CacheMgr {private static Map cacheMap = new HashMap(); private static Map cacheConfMap = new HashMap(); private CacheMgr(){ } private static CacheMgr cm = null; public synchronized static CacheMgr getInstance(){ if(cm==null){ cm = new CacheMgr(); Thread t = new ClearCache(); t.start(); } return cm; } /** * 增加缓存 * @param key * @param value * @param ccm 缓存对象 * @return */ public synchronized boolean addCache(Object key,Object value,CacheConfModel ccm){ boolean flag = false; cacheMap.put(key, value); cacheConfMap.put(key, ccm); System.out.println("now addcache=="+cacheMap.size()); return true; } /** * 删除缓存 * @param key * @return */ public synchronized boolean removeCache(Object key){ cacheMap.remove(key); cacheConfMap.remove(key); System.out.println("now removeCache=="+cacheMap.size()); return true; } /** * 删除所有缓存 */ public synchronized void removeAllCache(){ cacheMap.clear(); cacheConfMap.clear(); } /** * 在缓存中取值 * @param key * @return */ public synchronized Object getCacheContainer(Object key) {return getCacheContainer(key, false); } /** * 在缓存中取值 * @param key key值 * @param autoUpdate 在缓存中时间是否自动增加 * @return */ public synchronized Object getCacheContainer(Object key,boolean autoUpdate) {if (cacheMap.containsKey(key)) {if(autoUpdate){CacheConfModel ccm = (CacheConfModel)cacheConfMap.get(key);ccm.setBeginTime((new Date()).getTime());cacheConfMap.put(key, ccm);}return cacheMap.get(key);}else {return null;}} /** * 清除缓存的类 * @author wanglj * 继承Thread线程类 */ private static class ClearCache extends Thread{ public void run(){ while(true){ Set tempSet = new HashSet(); Set set = cacheConfMap.keySet(); Iterator it = set.iterator(); while(it.hasNext()){ Object key = it.next(); CacheConfModel ccm = (CacheConfModel)cacheConfMap.get(key); //比较是否需要清除 if(!ccm.isForever()){ if((new Date().getTime()-ccm.getBeginTime())>= ccm.getDurableTime()*60*1000){ //可以清除，先记录下来 tempSet.add(key); } } } //真正清除 Iterator tempIt = tempSet.iterator(); while(tempIt.hasNext()){ Object key = tempIt.next(); cacheMap.remove(key); cacheConfMap.remove(key); } System.out.println("now thread================>"+cacheMap.size()); //休息 try { Thread.sleep(60*1000L); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } }}