Java 使用 Map 实现缓存工具

以下代码参考于网上，做了小部分修改。

该代码实现了定时清除临时缓存的功能。

缓存管理类

 package com.wbproject.util.cache;

 import java.time.LocalDateTime;
 import java.time.format.DateTimeFormatter;
 import java.util.Date;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.Map;
 import java.util.Set;

 /**
  * 缓存管理类
  *
  * @author wangbo
  * @date 2018-03-07 12:43:41
  */
 public class CacheManage {

     private static Map<Object, Object> cacheMap = new HashMap<>();

     private static Map<Object, CacheConfModel> cacheConfMap = new HashMap<>();

     private static CacheManage cm = null;

     // 构造方法私有化
     private CacheManage() {
     }

     // 获取实例
     public static CacheManage getInstance() {
         if (cm == null) {
             cm = new CacheManage();
             // 第一次获取实例的时候启动线程
             Thread t = new ClearCache();
             t.start();
         }
         return cm;
     }

     /**
      * 添加缓存实体
      *
      * @param key
      * @param value
      * @param ccm
      * @return
      */
     public boolean addCache(Object key, Object value, CacheConfModel ccm) {
         System.out.println("开始增加缓存");
         boolean flag = false;
         try {
             cacheMap.put(key, value);
             cacheConfMap.put(key, ccm);
             System.out.println("增加缓存结束");
             flag = true;
         } catch (Exception e) {
             e.printStackTrace();
         }

         return flag;
     }

     /**
      * 获取缓存实体
      *
      * @param key
      * @return
      */
     public Object getValue(Object key) {
         Object object = cacheMap.get(key);
         if (object != null) {
             return object;
         } else {
             return null;
         }
     }

     /**
      * 获取缓存数据的数量
      *
      * @return
      */
     public int getSize() {
         return cacheMap.size();
     }

     /**
      * 删除缓存
      *
      * @param key
      * @return
      */
     public boolean removeCache(Object key) {
         boolean flag = false;
         try {
             cacheMap.remove(key);
             cacheConfMap.remove(key);
             flag = true;
         } catch (Exception e) {
             e.printStackTrace();
         }
         return flag;
     }

     /**
      * 清除缓存的线程
      */
     private static class ClearCache extends Thread {
         public void run() {
             while (true) {
                 // 记录要清除的key
                 Set<Object> tempSet = new HashSet<>();
                 Set<Object> set = cacheConfMap.keySet();
                 Iterator<Object> 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() * 1000L) {
                             // 可以清除，先记录下来
                             tempSet.add(key);
                         }
                     }
                 }
                 // 真正清除
                 Iterator<Object> tempIt = tempSet.iterator();
                 while (tempIt.hasNext()) {
                     Object key = tempIt.next();
                     cacheMap.remove(key);
                     cacheConfMap.remove(key);
                 }

                 LocalDateTime localDateTime = LocalDateTime.now();
                 System.out.println("当前时间为:" + localDateTime.format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")) + "，缓存大小==>" + cacheMap.size());
                 // 线程休息
                 try {
                     Thread.sleep(60 * 10 * 1000L);
                 } catch (InterruptedException e) {
                     e.printStackTrace();
                 }
             }
         }
     }

 }

缓存配置实体类

 package com.wbproject.util.cache;

 /**
  * 缓存配置实体类
  *
  * @author wangbo
  * @date 2018-03-07 12:42:56
  */
 public class CacheConfModel implements java.io.Serializable {

     private static final long serialVersionUID = 1L;

     private long beginTime;// 缓存开始时间

     private int durableTime;// 持续时间，秒

     private boolean isForever = false;// 是否持久

     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;
     }

 }

最后贴上操作缓存的工具类，简单写了几个用到的，如果没有可自行添加：

 package com.wbproject.util.cache;

 import java.util.Date;

 /**
  * 操作缓存的工具类
  *
  * @author wangbo
  * @date 2018-03-07 13:01:54
  */
 public class CacheUtil {

     /**
      * 添加缓存
      *
      * @param key
      * @param value
      */
     public static boolean addCache(Object key, Object value) {
         CacheManage cm = CacheManage.getInstance();
         CacheConfModel cModel = new CacheConfModel();
         cModel.setForever(true);
         return cm.addCache(key, value, cModel);
     }

     /**
      * 添加临时缓存
      *
      * @param key
      * @param value
      * @param durableTime
      */
     public static boolean addTempCache(Object key, Object value, int durableTime) {
         CacheManage cm = CacheManage.getInstance();
         CacheConfModel cModel = new CacheConfModel();
         cModel.setBeginTime(new Date().getTime());
         cModel.setDurableTime(durableTime);
         cModel.setForever(false);
         return cm.addCache(key, value, cModel);
     }

     /**
      * 获取缓存
      *
      * @param key
      * @return
      */
     public static Object getValue(Object key) {
         CacheManage cm = CacheManage.getInstance();
         Object ob = cm.getValue(key);
         if (ob == null) {
             return null;
         }
         return ob;
     }

     /**
      * 获取字符串缓存
      *
      * @param key
      * @return
      */
     public static String getStringValue(Object key) {
         CacheManage cm = CacheManage.getInstance();
         Object ob = cm.getValue(key);
         if (ob == null) {
             return null;
         }
         return ob.toString();
     }

 }