本地缓存工具类

红太狼 2022-08-30 11:41 186阅读 0赞

import java.util.concurrent.ConcurrentHashMap;
    import java.util.concurrent.ConcurrentMap;
    
    /**
     * local cache tool
     *
     * @author ws 2021-07-22 21:37:34
     */
    public class LocalCacheUtil {
    
        private static ConcurrentMap<String, LocalCacheData> cacheRepository = new ConcurrentHashMap<String, LocalCacheData>();   // 类型建议用抽象父类，兼容性更好；
        private static class LocalCacheData{
            private String key;
            private Object val;
            private long timeoutTime;
    
            public LocalCacheData() {
            }
    
            public LocalCacheData(String key, Object val, long timeoutTime) {
                this.key = key;
                this.val = val;
                this.timeoutTime = timeoutTime;
            }
    
            public String getKey() {
                return key;
            }
    
            public void setKey(String key) {
                this.key = key;
            }
    
            public Object getVal() {
                return val;
            }
    
            public void setVal(Object val) {
                this.val = val;
            }
    
            public long getTimeoutTime() {
                return timeoutTime;
            }
    
            public void setTimeoutTime(long timeoutTime) {
                this.timeoutTime = timeoutTime;
            }
        }
    
    
        /**
         * set cache
         *
         * @param key
         * @param val
         * @param cacheTime
         * @return
         */
        public static boolean set(String key, Object val, long cacheTime){
    
            // clean timeout cache, before set new cache (avoid cache too much)
            cleanTimeoutCache();
    
            // set new cache
            if (key==null || key.trim().length()==0) {
                return false;
            }
            if (val == null) {
                remove(key);
            }
            if (cacheTime <= 0) {
                remove(key);
            }
            long timeoutTime = System.currentTimeMillis() + cacheTime;
            LocalCacheData localCacheData = new LocalCacheData(key, val, timeoutTime);
            cacheRepository.put(localCacheData.getKey(), localCacheData);
            return true;
        }
    
        /**
         * remove cache
         *
         * @param key
         * @return
         */
        public static boolean remove(String key){
            if (key==null || key.trim().length()==0) {
                return false;
            }
            cacheRepository.remove(key);
            return true;
        }
    
        /**
         * get cache
         *
         * @param key
         * @return
         */
        public static Object get(String key){
            if (key==null || key.trim().length()==0) {
                return null;
            }
            LocalCacheData localCacheData = cacheRepository.get(key);
            if (localCacheData!=null && System.currentTimeMillis()<localCacheData.getTimeoutTime()) {
                return localCacheData.getVal();
            } else {
                remove(key);
                return null;
            }
        }
    
        /**
         * clean timeout cache
         *
         * @return
         */
        public static boolean cleanTimeoutCache(){
            if (!cacheRepository.keySet().isEmpty()) {
                for (String key: cacheRepository.keySet()) {
                    LocalCacheData localCacheData = cacheRepository.get(key);
                    if (localCacheData!=null && System.currentTimeMillis()>=localCacheData.getTimeoutTime()) {
                        cacheRepository.remove(key);
                    }
                }
            }
            return true;
        }
    
    }