摘要：
以下代码在互联网上引用，并进行了轻微修改。此代码实现了定期清除临时缓存的功能。缓存管理类1packagecom.wbproject.util。隐藏物23导入java.time。本地日期时间；4导入java.time.format。日期时间格式设置工具；5导入java.util。日期6导入java.util。HashMap；7导入java.util。HashSet；8导入java.util。迭代器；9导入java.util。地图10导入java.util。设置1112/**13*缓存管理类14*15*@authorwangbo16*@date2018-03-0712:43:4117*/18publicclassCacheManage｛1920privatestaticMap＜Object，Object＞cacheMap＝newHashMap＜˃（）；2122privateStation＜Object，CacheConfModel＞cacheConfMap＝newHashMap＜˃CacheManagegetInstance（）｛32if｛33cm＝newCacheManage（）；34//首次获取实例时启动线程35Thread＝newClearCache（）；36t.Start（）；37｝38returncm；39｝4041/**42*添加缓存实体43*44*@paramkey45*@paramvalue46*@paramccm47*@return48*/49publicpooldaddCache｛50System.out.println；51booleanflag=false；52try｛53cacheMap.put；54cacheConfMap.pput；55System.out.prprintln；56flag=true；57｝catch｛58e.printStackTrace（）；59｝6061returnflag；62｝6364/**65*获取缓存实体66*67*@paramkey68*@return69*/70publicObjectgetValue｛71Objectobject=cacheMap.Get；72if（object！
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
1 package com.wbproject.util.cache; 2 3 import java.time.LocalDateTime; 4 import java.time.format.DateTimeFormatter; 5 import java.util.Date; 6 import java.util.HashMap; 7 import java.util.HashSet; 8 import java.util.Iterator; 9 import java.util.Map; 10 import java.util.Set; 11 12 /** 13 * 缓存管理类 14 * 15 * @author wangbo 16 * @date 2018-03-07 12:43:41 17 */ 18 public class CacheManage { 19 20 private static Map<Object, Object> cacheMap = new HashMap<>(); 21 22 private static Map<Object, CacheConfModel> cacheConfMap = new HashMap<>(); 23 24 private static CacheManage cm = null; 25 26 // 构造方法私有化 27 private CacheManage() { 28 } 29 30 // 获取实例 31 public static CacheManage getInstance() { 32 if (cm == null) { 33 cm = new CacheManage(); 34 // 第一次获取实例的时候启动线程 35 Thread t = new ClearCache(); 36 t.start(); 37 } 38 return cm; 39 } 40 41 /** 42 * 添加缓存实体 43 * 44 * @param key 45 * @param value 46 * @param ccm 47 * @return 48 */ 49 public boolean addCache(Object key, Object value, CacheConfModel ccm) { 50 System.out.println("开始增加缓存"); 51 boolean flag = false; 52 try { 53 cacheMap.put(key, value); 54 cacheConfMap.put(key, ccm); 55 System.out.println("增加缓存结束"); 56 flag = true; 57 } catch (Exception e) { 58 e.printStackTrace(); 59 } 60 61 return flag; 62 } 63 64 /** 65 * 获取缓存实体 66 * 67 * @param key 68 * @return 69 */ 70 public Object getValue(Object key) { 71 Object object = cacheMap.get(key); 72 if (object != null) { 73 return object; 74 } else { 75 return null; 76 } 77 } 78 79 /** 80 * 获取缓存数据的数量 81 * 82 * @return 83 */ 84 public int getSize() { 85 return cacheMap.size(); 86 } 87 88 /** 89 * 删除缓存 90 * 91 * @param key 92 * @return 93 */ 94 public boolean removeCache(Object key) { 95 boolean flag = false; 96 try { 97 cacheMap.remove(key); 98 cacheConfMap.remove(key); 99 flag = true; 100 } catch (Exception e) { 101 e.printStackTrace(); 102 } 103 return flag; 104 } 105 106 /** 107 * 清除缓存的线程 108 */ 109 private static class ClearCache extends Thread { 110 public void run() { 111 while (true) { 112 // 记录要清除的key 113 Set<Object> tempSet = new HashSet<>(); 114 Set<Object> set = cacheConfMap.keySet(); 115 Iterator<Object> it = set.iterator(); 116 while (it.hasNext()) { 117 Object key = it.next(); 118 CacheConfModel ccm = (CacheConfModel) cacheConfMap.get(key); 119 // 比较是否需要清除 120 if (!ccm.isForever()) { 121 if ((new Date().getTime() - ccm.getBeginTime()) >= ccm.getDurableTime() * 1000L) { 122 // 可以清除，先记录下来 123 tempSet.add(key); 124 } 125 } 126 } 127 // 真正清除 128 Iterator<Object> tempIt = tempSet.iterator(); 129 while (tempIt.hasNext()) { 130 Object key = tempIt.next(); 131 cacheMap.remove(key); 132 cacheConfMap.remove(key); 133 } 134 135 LocalDateTime localDateTime = LocalDateTime.now(); 136 System.out.println("当前时间为:" + localDateTime.format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")) + "，缓存大小==>" + cacheMap.size()); 137 // 线程休息 138 try { 139 Thread.sleep(60 * 10 * 1000L); 140 } catch (InterruptedException e) { 141 e.printStackTrace(); 142 } 143 } 144 } 145 } 146 147 }
缓存配置实体类
1 package com.wbproject.util.cache; 2 3 /** 4 * 缓存配置实体类 5 * 6 * @author wangbo 7 * @date 2018-03-07 12:42:56 8 */ 9 public class CacheConfModel implements java.io.Serializable { 10 11 private static final long serialVersionUID = 1L; 12 13 private long beginTime;// 缓存开始时间 14 15 private int durableTime;// 持续时间，秒 16 17 private boolean isForever = false;// 是否持久 18 19 public long getBeginTime() { 20 return beginTime; 21 } 22 23 public void setBeginTime(long beginTime) { 24 this.beginTime = beginTime; 25 } 26 27 public boolean isForever() { 28 return isForever; 29 } 30 31 public void setForever(boolean isForever) { 32 this.isForever = isForever; 33 } 34 35 public int getDurableTime() { 36 return durableTime; 37 } 38 39 public void setDurableTime(int durableTime) { 40 this.durableTime = durableTime; 41 } 42 43 }
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：
1 package com.wbproject.util.cache; 2 3 import java.util.Date; 4 5 /** 6 * 操作缓存的工具类 7 * 8 * @author wangbo 9 * @date 2018-03-07 13:01:54 10 */ 11 public class CacheUtil { 12 13 /** 14 * 添加缓存 15 * 16 * @param key 17 * @param value 18 */ 19 public static boolean addCache(Object key, Object value) { 20 CacheManage cm = CacheManage.getInstance(); 21 CacheConfModel cModel = new CacheConfModel(); 22 cModel.setForever(true); 23 return cm.addCache(key, value, cModel); 24 } 25 26 /** 27 * 添加临时缓存 28 * 29 * @param key 30 * @param value 31 * @param durableTime 32 */ 33 public static boolean addTempCache(Object key, Object value, int durableTime) { 34 CacheManage cm = CacheManage.getInstance(); 35 CacheConfModel cModel = new CacheConfModel(); 36 cModel.setBeginTime(new Date().getTime()); 37 cModel.setDurableTime(durableTime); 38 cModel.setForever(false); 39 return cm.addCache(key, value, cModel); 40 } 41 42 /** 43 * 获取缓存 44 * 45 * @param key 46 * @return 47 */ 48 public static Object getValue(Object key) { 49 CacheManage cm = CacheManage.getInstance(); 50 Object ob = cm.getValue(key); 51 if (ob == null) { 52 return null; 53 } 54 return ob; 55 } 56 57 /** 58 * 获取字符串缓存 59 * 60 * @param key 61 * @return 62 */ 63 public static String getStringValue(Object key) { 64 CacheManage cm = CacheManage.getInstance(); 65 Object ob = cm.getValue(key); 66 if (ob == null) { 67 return null; 68 } 69 return ob.toString(); 70 } 71 72 }