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Java实现简单的缓存机制原理

关键词:Java缓存机制Java实现简单的缓存机制原理  阅读(2249) 赞(15)

[摘要]本文主要是对Java实现简单的缓存机制原理的讲解,希望对大家学习Java实现简单的缓存机制原理有所帮助。

  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();

  }

  }

  }

  }

  }



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