java实现简单的缓存机制原理[回钦波原创]
package com.qinbo.hui;
/*
? 设计思想来自－回钦波（qq:444084929)
*/
public class CacheConfModel implements java.io.Serializable{
? private long beginTime;
? private boolean isForever = false;
? private int durableTime;
? public long getBeginTime() {
?? return beginTime;
? }
? public void setBeginTime(long beginTime) {
?? this.beginTime = beginTime;
? }
? public boolean isForever() {
?? return isForever;
? }
? public void setForever(boolean isForever) {
?? this.isForever = isForever;
? }
? public int getDurableTime() {
?? return durableTime;
? }
? public void setDurableTime(int durableTime) {
?? this.durableTime = durableTime;
? }
?}
?
?
?
?
package com.qinbo.hui;
import java.util.*;
import test4.CacheConfModel;
/*
? 设计思想来自－回钦波（qq:444084929)
*/
public class CacheMgr {
?private static Map cacheMap = new HashMap();
?private static Map cacheConfMap = new HashMap();
?
?private CacheMgr(){
?
?}
?private static CacheMgr cm = null;
?public 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? 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? boolean removeCache(Object key){
? cacheMap.remove(key);
? cacheConfMap.remove(key);
?
? System.out.println("now removeCache=="+cacheMap.size());
?
? return true;
?}
?/**
? * 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();
??? }
?? }
? }
?}
}
?
?
