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  • Java 中常用缓存Cache机制的实现

    所谓缓存,就是将程序或系统经常要调用的对象存在内存中,一遍其使用时可以快速调用,不必再去创建新的重复的实例。这样做可以减少系统开销,提高系统效率。

    所谓缓存,就是将程序或系统经常要调用的对象存在内存中,一遍其使用时可以快速调用,不必再去创建新的重复的实例。这样做可以减少系统开销,提高系统效率。

    缓存主要可分为二大类: 

    一、通过文件缓存,顾名思义文件缓存是指把数据存储在磁盘上,不管你是以XML格式,序列化文件DAT格式还是其它文件格式;  

    二、内存缓存,也就是实现一个类中静态Map,对这个Map进行常规的增删查. 

    代码如下:

    package lhm.hcy.guge.frameset.cache; 
     
    import java.util.*; 
     
     //Description: 管理缓存 
     
     //可扩展的功能:当chche到内存溢出时必须清除掉最早期的一些缓存对象,这就要求对每个缓存对象保存创建时间 
     
    public class CacheManager { 
        private static HashMap cacheMap = new HashMap(); 
     
        //单实例构造方法 
        private CacheManager() { 
            super(); 
        } 
        //获取布尔值的缓存 
        public static boolean getSimpleFlag(String key){ 
            try{ 
                return (Boolean) cacheMap.get(key); 
            }catch(NullPointerException e){ 
                return false; 
            } 
        } 
        public static long getServerStartdt(String key){ 
            try { 
                return (Long)cacheMap.get(key); 
            } catch (Exception ex) { 
                return 0; 
            } 
        } 
        //设置布尔值的缓存 
        public synchronized static boolean setSimpleFlag(String key,boolean flag){ 
            if (flag && getSimpleFlag(key)) {//假如为真不允许被覆盖 
                return false; 
            }else{ 
                cacheMap.put(key, flag); 
                return true; 
            } 
        } 
        public synchronized static boolean setSimpleFlag(String key,long serverbegrundt){ 
            if (cacheMap.get(key) == null) { 
                cacheMap.put(key,serverbegrundt); 
                return true; 
            }else{ 
                return false; 
            } 
        } 
     
     
        //得到缓存。同步静态方法 
        private synchronized static Cache getCache(String key) { 
            return (Cache) cacheMap.get(key); 
        } 
     
        //判断是否存在一个缓存 
        private synchronized static boolean hasCache(String key) { 
            return cacheMap.containsKey(key); 
        } 
     
        //清除所有缓存 
        public synchronized static void clearAll() { 
            cacheMap.clear(); 
        } 
     
        //清除某一类特定缓存,通过遍历HASHMAP下的所有对象,来判断它的KEY与传入的TYPE是否匹配 
        public synchronized static void clearAll(String type) { 
            Iterator i = cacheMap.entrySet().iterator(); 
            String key; 
            ArrayList arr = new ArrayList(); 
            try { 
                while (i.hasNext()) { 
                    java.util.Map.Entry entry = (java.util.Map.Entry) i.next(); 
                    key = (String) entry.getKey(); 
                    if (key.startsWith(type)) { //如果匹配则删除掉 
                        arr.add(key); 
                    } 
                } 
                for (int k = 0; k < arr.size(); k++) { 
                    clearOnly(arr.get(k)); 
                } 
            } catch (Exception ex) { 
                ex.printStackTrace(); 
            } 
        } 
     
        //清除指定的缓存 
        public synchronized static void clearOnly(String key) { 
            cacheMap.remove(key); 
        } 
     
        //载入缓存 
        public synchronized static void putCache(String key, Cache obj) { 
            cacheMap.put(key, obj); 
        } 
     
        //获取缓存信息 
        public static Cache getCacheInfo(String key) { 
     
            if (hasCache(key)) { 
                Cache cache = getCache(key); 
                if (cacheExpired(cache)) { //调用判断是否终止方法 
                    cache.setExpired(true); 
                } 
                return cache; 
            }else 
                return null; 
        } 
     
        //载入缓存信息 
        public static void putCacheInfo(String key, Cache obj, long dt,boolean expired) { 
            Cache cache = new Cache(); 
            cache.setKey(key); 
            cache.setTimeOut(dt + System.currentTimeMillis()); //设置多久后更新缓存 
            cache.setValue(obj); 
            cache.setExpired(expired); //缓存默认载入时,终止状态为FALSE 
            cacheMap.put(key, cache); 
        } 
        //重写载入缓存信息方法 
        public static void putCacheInfo(String key,Cache obj,long dt){ 
            Cache cache = new Cache(); 
            cache.setKey(key); 
            cache.setTimeOut(dt+System.currentTimeMillis()); 
            cache.setValue(obj); 
            cache.setExpired(false); 
            cacheMap.put(key,cache); 
        } 
     
        //判断缓存是否终止 
        public static boolean cacheExpired(Cache cache) { 
            if (null == cache) { //传入的缓存不存在 
                return false; 
            } 
            long nowDt = System.currentTimeMillis(); //系统当前的毫秒数 
            long cacheDt = cache.getTimeOut(); //缓存内的过期毫秒数 
            if (cacheDt <= 0||cacheDt>nowDt) { //过期时间小于等于零时,或者过期时间大于当前时间时,则为FALSE 
                return false; 
            } else { //大于过期时间 即过期 
                return true; 
            } 
        } 
     
        //获取缓存中的大小 
        public static int getCacheSize() { 
            return cacheMap.size(); 
        } 
     
        //获取指定的类型的大小 
        public static int getCacheSize(String type) { 
            int k = 0; 
            Iterator i = cacheMap.entrySet().iterator(); 
            String key; 
            try { 
                while (i.hasNext()) { 
                    java.util.Map.Entry entry = (java.util.Map.Entry) i.next(); 
                    key = (String) entry.getKey(); 
                    if (key.indexOf(type) != -1) { //如果匹配则删除掉 
                        k++; 
                    } 
                } 
            } catch (Exception ex) { 
                ex.printStackTrace(); 
            } 
     
            return k; 
        } 
     
        //获取缓存对象中的所有键值名称 
        public static ArrayList getCacheAllkey() { 
            ArrayList a = new ArrayList(); 
            try { 
                Iterator i = cacheMap.entrySet().iterator(); 
                while (i.hasNext()) { 
                    java.util.Map.Entry entry = (java.util.Map.Entry) i.next(); 
                    a.add((String) entry.getKey()); 
                } 
            } catch (Exception ex) {} finally { 
                return a; 
            } 
        } 
     
        //获取缓存对象中指定类型 的键值名称 
        public static ArrayList getCacheListkey(String type) { 
            ArrayList a = new ArrayList(); 
            String key; 
            try { 
                Iterator i = cacheMap.entrySet().iterator(); 
                while (i.hasNext()) { 
                    java.util.Map.Entry entry = (java.util.Map.Entry) i.next(); 
                    key = (String) entry.getKey(); 
                    if (key.indexOf(type) != -1) { 
                        a.add(key); 
                    } 
                } 
            } catch (Exception ex) {} finally { 
                return a; 
            } 
        } 
     
    } 
     
     
    package lhm.hcy.guge.frameset.cache; 
     
    public class Cache { 
            private String key;//缓存ID 
            private Object value;//缓存数据 
            private long timeOut;//更新时间 
            private boolean expired; //是否终止 
            public Cache() { 
                    super(); 
            } 
     
            public Cache(String key, Object value, long timeOut, boolean expired) { 
                    this.key = key; 
                    this.value = value; 
                    this.timeOut = timeOut; 
                    this.expired = expired; 
            } 
     
            public String getKey() { 
                    return key; 
            } 
     
            public long getTimeOut() { 
                    return timeOut; 
            } 
     
            public Object getValue() { 
                    return value; 
            } 
     
            public void setKey(String string) { 
                    key = string; 
            } 
     
            public void setTimeOut(long l) { 
                    timeOut = l; 
            } 
     
            public void setValue(Object object) { 
                    value = object; 
            } 
     
            public boolean isExpired() { 
                    return expired; 
            } 
     
            public void setExpired(boolean b) { 
                    expired = b; 
            } 
    } 
     
    //测试类, 
    class Test { 
        public static void main(String[] args) { 
            System.out.println(CacheManager.getSimpleFlag("alksd")); 
    //        CacheManager.putCache("abc", new Cache()); 
    //        CacheManager.putCache("def", new Cache()); 
    //        CacheManager.putCache("ccc", new Cache()); 
    //        CacheManager.clearOnly(""); 
    //        Cache c = new Cache(); 
    //        for (int i = 0; i < 10; i++) { 
    //            CacheManager.putCache("" + i, c); 
    //        } 
    //        CacheManager.putCache("aaaaaaaa", c); 
    //        CacheManager.putCache("abchcy;alskd", c); 
    //        CacheManager.putCache("cccccccc", c); 
    //        CacheManager.putCache("abcoqiwhcy", c); 
    //        System.out.println("删除前的大小:"+CacheManager.getCacheSize()); 
    //        CacheManager.getCacheAllkey(); 
    //        CacheManager.clearAll("aaaa"); 
    //        System.out.println("删除后的大小:"+CacheManager.getCacheSize()); 
    //        CacheManager.getCacheAllkey(); 
     
     
        } 
    } 
    

    spring中的redis service实现

    package com.eshore.ismp.cache.redis;
    
    import java.io.UnsupportedEncodingException;
    import java.util.ArrayList;
    import java.util.Collection;
    import java.util.Collections;
    import java.util.HashSet;
    import java.util.List;
    import java.util.Map;
    import java.util.Map.Entry;
    import java.util.Set;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.dao.DataAccessException;
    import org.springframework.data.redis.connection.RedisConnection;
    import org.springframework.data.redis.core.RedisCallback;
    import org.springframework.data.redis.core.RedisTemplate;
    import org.springframework.stereotype.Service;
    
    @Service
    public class RedisService {
    
    	private static String redisCode = "utf-8";
    	
    	@Autowired
    	private RedisTemplate<String, String> redisTemplate;
    
    	/**
    	 * 从指定的列表右边出队,添加到目的列表中
    	 * 
    	 * @param srckey
    	 *            源列表
    	 * @param dstkey
    	 *             目的列表
    	 * @return
    	 */
    	public String rpoppush(final String srckey, final String dstkey) {
    		return redisTemplate.execute(new RedisCallback<String>() {
    			public String doInRedis(RedisConnection connection)
    					throws DataAccessException {
    				try {
    					return new String (connection.rPopLPush(srckey.getBytes(), dstkey.getBytes()), redisCode);
    				} catch (UnsupportedEncodingException e) {
    					e.printStackTrace();
    				}
    				return "";
    			}
    		});
    	}
    	/**
    	 * 获取指定列表的范围数据
    	 * 
    	 * @param key
    	 *             列表名
    	 * @param start
    	 *             开始位置
    	 * @param end
    	 *             结束位置
    	 * @return
    	 */
    	public List<String> lrange(final String key, final int start, final int end) {
    		return redisTemplate.execute(new RedisCallback<List<String>>() {
    			List<String> result = new ArrayList<String>();
    			public List<String> doInRedis(RedisConnection connection)
    					throws DataAccessException {
    				List<byte[]> bytelist= connection.lRange(key.getBytes(), start, end);
    				for (byte[] b : bytelist) {
    					try {
    						result.add(new String(b, redisCode));
    					} catch (UnsupportedEncodingException e) {
    						e.printStackTrace();
    					}
    				}
    				return result;
    			}
    		});
    	}
    	/**
    	 * 从队列的左边取出一条数据
    	 * 
    	 * @param key
    	 *             列表名
    	 * @return
    	 */
    	public String lpop(final String key) {
    		return redisTemplate.execute(new RedisCallback<String>() {
    			public String doInRedis(RedisConnection connection)
    					throws DataAccessException {
    				byte[] result = connection.lPop(key.getBytes());
    				if (result != null) {
    					try {
    						return new String (result , redisCode);
    					} catch (UnsupportedEncodingException e) {
    						e.printStackTrace();
    					}
    				}
    				return "";
    			}
    		});
    	}
    	
    	/**
    	 * 从队列的左边取出一条数据
    	 * 
    	 * @param key
    	 *             列表名
    	 * @return
    	 */
    	public List<?> lpop(final String key,final int size) {
    		List<Object> list =  redisTemplate.executePipelined(new RedisCallback<List<Object>>() {
    			public List<Object> doInRedis(RedisConnection connection)
    					throws DataAccessException {
    				byte[] keyBytes = key.getBytes();
    				for(int i =0 ; i< size; i++){
    					connection.lPop(keyBytes);
    				}
    				return null;
    			}
    		});
    		list.removeAll(Collections.singleton(null));
    		return list;
    	}
    	
    	/**
    	 * 从列表右边添加数据
    	 * 
    	 * @param key
    	 *            列表名
    	 * @param values
    	 *            数据
    	 * @return
    	 */
    	public long rpush(final String key, final String... values) {
            return redisTemplate.execute(new RedisCallback<Long>() {
                public Long doInRedis(RedisConnection connection)
                        throws DataAccessException {
                    long result = 0;
                    for (String v : values) {
                    	result = connection.rPush(key.getBytes(), v.getBytes());
                    }
                    return result;
                }
            });
    	}
    	
    	/**
    	 * 从列表右边添加数据
    	 * 
    	 * @param key
    	 *            列表名
    	 * @param values
    	 *            数据
    	 * @return
    	 */
    	public long rpush(final String key, final Collection<String> values) {
    		return redisTemplate.opsForList().rightPushAll(key, values);
    	}
    	
    	public int hmset(final String key, final Map<String,String> values) {
    		try{
    		 redisTemplate.opsForHash().putAll(key, values);
    		}catch(Exception e){
    			e.printStackTrace();
    			return -1;
    		}
    		return 0 ;
    	}
    	public String hget(final String key, final String field){
    		Object obj =redisTemplate.opsForHash().get(key, field);
    		return String.valueOf(obj);
    	}
    	
    	public List<?> hkeys(final String key){
    		return redisTemplate.execute(new RedisCallback<List<Object>>(){
    			List<Object> list = new ArrayList<Object>();
    			public List<Object> doInRedis(RedisConnection connection)
    					throws DataAccessException {
    				Set<byte[]> sets=connection.hKeys(key.getBytes());
    				if(!sets.isEmpty()){
    					for(byte[] b : sets){
    						list.add(redisTemplate.getValueSerializer().deserialize(b).toString());
    					}
    					return list;
    				}
    				return null;
    			}
    		});
    	}
    	
    	/**
    	 * 删除hash表中field
    	 */
    	public void hdel(final String key,final String field){
    		redisTemplate.opsForHash().delete(key, field);
    	}
    	/**
    	 * 从列表右边添加数据,并且设置列表的存活时间
    	 * 
    	 * @param key
    	 *            列表名
    	 * @param liveTime
    	 *            存活时间(单位 秒)
    	 * @param values
    	 *            数据
    	 * @return
    	 */
    	public long rpush(final String key, final int liveTime, final String... values) {
    		return redisTemplate.execute(new RedisCallback<Long>() {
    			public Long doInRedis(RedisConnection connection)
    					throws DataAccessException {
    				long result = 0; 
    				for (String v : values) {
    					connection.rPush(key.getBytes(), v.getBytes());
    				}
    				if (liveTime > 0) {
    					connection.expire(key.getBytes(), liveTime);
    				}	
    				return result;
    			}
    		});
    	}
    	/**
    	 * 从队列的右边取出一条数据
    	 * 
    	 * @param key
    	 *            列表名
    	 * @return
    	 */
    	public String rpop(final String key) {
    		return redisTemplate.execute(new RedisCallback<String>() {
    			public String doInRedis(RedisConnection connection)
    					throws DataAccessException {
    				byte[] result = connection.rPop(key.getBytes());
    				if(result != null ){
    					try {
    						return new String (result, redisCode);
    					} catch (UnsupportedEncodingException e) {
    						e.printStackTrace();
    					}
    				}
    				return "";
    			}
    		});
    	}
    	/**
    	 * 把一个值添加到对应列表中
    	 * 
    	 * @param key
    	 *            列表名
    	 * @param index
    	 *             添加的位置
    	 * @param value
    	 *             数据
    	 * @return
    	 */
    	public String lset(final String key, final long index, final String value) {
    		return redisTemplate.execute(new RedisCallback<String>() {
    			public String doInRedis(RedisConnection connection)
    					throws DataAccessException {
    				connection.lSet(key.getBytes(), index, value.getBytes());
    				return "success";
    			}
    		});
    	}
    	/**
    	 * 把所有数据添加到一个列表中
    	 * 
    	 * @param key
    	 *            列表名
    	 * @param values
    	 *             数据
    	 * @return
    	 */
    	public long lpush(String key, String... values) {
    		return this.lpush(key, 0, values);
    	}
    	/**
    	 * 把所有数据添加到一个列表中,并且设置列表的存活时间
    	 * 
    	 * @param key
    	 *            列表名
    	 * @param values
    	 *            数据
    	 * @param liveTime
    	 *            存活时间--单位(秒)
    	 * @return
    	 */
    	public long lpush(final String key,final  int liveTime, final String... values) {
    		return redisTemplate.execute(new RedisCallback<Long>() {
    			public Long doInRedis(RedisConnection connection)
    					throws DataAccessException {
    				long result = 0;
    				for (String v : values){
    					result = connection.lPush(key.getBytes(), v.getBytes());
    				}
    				if (liveTime > 0) {
    					connection.expire(key.getBytes(), liveTime);
    				}
    				return result;
    			}
    		});
    	}
    	/**
    	 * 返回列表的长度
    	 * 
    	 * @param key
    	 * @return
    	 */
    	public long llen(final String key) {
    		return redisTemplate.execute(new RedisCallback<Long>() {
    			public Long doInRedis(RedisConnection connection)
    					throws DataAccessException {
    				return connection.lLen(key.getBytes());
    			}
    		});
    	}
    	/**
    	 * 删除列表中对应值的元素
    	 * 
    	 * @param key
    	 *            列表名
    	 * @param count
    	 *            删除多少个相同的元素
    	 * @param value
    	 *            数据
    	 * @return
    	 */
    	public long lrem(final String key, final long count, final String value) {
    		return redisTemplate.execute(new RedisCallback<Long>() {
    			public Long doInRedis(RedisConnection connection)
    					throws DataAccessException {
    				return connection.lRem(key.getBytes(), count, value.getBytes());
    			}
    		});
    	}
    	/**
    	 * 通过keys批量删除
    	 * 
    	 * @param key
    	 */
    	public long del(final String... keys) {
    		return redisTemplate.execute(new RedisCallback<Long>() {
    			public Long doInRedis(RedisConnection connection)
    					throws DataAccessException {
    				long result = 0;
    				for (String k : keys) {
    					result = connection.del(k.getBytes());
    				}
    				return result;
    			}
    		});
    	}
    	
    	/**
    	 * 
    	 * //DESC 删除单个key
    	 * @time: 2016年5月27日 上午9:00:36
    	 * @param key
    	 * @return
    	 * @throws
    	 */
    	public long del(final String key){
    		return redisTemplate.execute(new RedisCallback<Long>(){
    			@Override
    			public Long doInRedis(RedisConnection connection)
    					throws DataAccessException {
    				return connection.del(key.getBytes());
    			}
    			
    		});
    	}
    	
    	
    	/**
    	 * 添加key value 并且设置存活时间(byte)
    	 * 
    	 * @param key
    	 * @param value
    	 * @param liveTime
    	 */
    	public void set(final byte[] key, final byte[] value, final long liveTime) {
    		redisTemplate.execute(new RedisCallback<Long>() {
    			public Long doInRedis(RedisConnection connection)
    					throws DataAccessException {
    				connection.set(key, value);
                    if (liveTime > 0) {
                        connection.expire(key, liveTime);
                    }
    				return 1L;
    			}
    		});
    		
    	}
    	/**
    	 * 添加key value 并且设置存活时间
    	 * 
    	 * @param key
    	 * @param value
    	 * @param liveTime
    	 *            单位秒
    	 */
    	public void set(String key, String value, long liveTime) {
    		this.set(key.getBytes(), value.getBytes(), liveTime);
    		
    	}
    	/**
    	 * 添加key value
    	 * 
    	 * @param key
    	 * @param value
    	 */
    	public void set(String key, String value) {
    		this.set(key, value, 0L);
    	}
    	
    	/**
    	 * 添加key value
    	 * 
    	 * @param key
    	 * @param value
    	 */
    	public void setMulti(final Map<String,String> map) {
    		setMulti(map,0L);
    	}
    	
    	/**
    	 * 添加key value
    	 * 
    	 * @param key
    	 * @param value
    	 */
    	public void setMulti(final Map<String,String> map,final long liveTime) {
    		 redisTemplate.executePipelined(new RedisCallback<String>() {
    			public String doInRedis(RedisConnection connection)
    					throws DataAccessException {
    				Set<Map.Entry<String, String >> set = map.entrySet();
    				for (Entry<String, String> entry : set) {
    					connection.set(entry.getKey().getBytes(), entry.getValue().getBytes());
    					if (liveTime > 0) {
    		                connection.expire(entry.getKey().getBytes(), liveTime);
    		            }
    				}
    				return null;
    			}
    		});
    	}
    	/**
    	 * 添加key value (字节)(序列化)
    	 * 
    	 * @param key
    	 * @param value
    	 */
    	public void set(byte[] key, byte[] value) {
    		this.set(key, value, 0L);
    		
    	}
    	/**
    	 * 获取redis value (String)
    	 * 
    	 * @param key
    	 * @return
    	 */
    	public String get(final String key) {
    		return redisTemplate.execute(new RedisCallback<String>() {
    			public String doInRedis(RedisConnection connection)
    					throws DataAccessException {
    			byte[] result = connection.get(key.getBytes());
    			if (result != null) {
    				try {
    					return new String (result ,redisCode);
    				} catch (UnsupportedEncodingException e) {
    					e.printStackTrace();
    				}	
    			}
    			return "";
    			}
    		});
    	}
    	/**
    	 * 如果key不存在添加key value 并且设置存活时间(byte),当key已经存在时,就不做任何操作
    	 * 
    	 * @param key
    	 * @param value
    	 * @param liveTime
    	 */
    	public long setnx(final byte[] key, final byte[] value, final long liveTime) {
    		return redisTemplate.execute(new RedisCallback<Long>() {
    			public Long doInRedis(RedisConnection connection)
    					throws DataAccessException {
    				long result = 0l;
    				boolean isSuccess = connection.setNX(key, value);
                    if (isSuccess) {
                    	if (liveTime > 0) {
                            connection.expire(key, liveTime);
                        }
    					result = 1l;
    				}
    				return result;
    			}
    		});
    	}
    	/**
    	 * 如果key不存在添加key value 并且设置存活时间,当key已经存在时,就不做任何操作
    	 * 
    	 * @param key
    	 * @param value
    	 * @param liveTime
    	 *            单位秒
    	 */
    	public long setnx(String key, String value, long liveTime) {
    		return this.setnx(key.getBytes(), value.getBytes(), liveTime);
    		
    	}
    	/**
    	 * 如果key不存在添加key value,当key已经存在时,就不做任何操作
    	 * 
    	 * @param key
    	 * @param value
    	 */
    	public long setnx(String key, String value) {
    		return this.setnx(key, value, 0L);
    	}
    	/**
    	 * 如果key不存在添加key value (字节)(序列化),当key已经存在时,就不做任何操作
    	 * 
    	 * @param key
    	 * @param value
    	 */
    	public long setnx(byte[] key, byte[] value) {
    		return this.setnx(key, value, 0L);
    		
    	}
    	/**
    	 * 通过正则匹配keys
    	 * 
    	 * @param pattern
    	 * @return
    	 */
    	public Set<String> keys(final String pattern) {
    		return redisTemplate.execute(new RedisCallback<Set<String>>() {
    			public Set<String> doInRedis(RedisConnection connection)
    					throws DataAccessException {
    			Set<String> result = new HashSet<String>();
    			Set<byte[]>	data = connection.keys(pattern.getBytes());
    			for(byte[] d : data){
    				try {
    					result.add(new String(d,redisCode));
    				} catch (UnsupportedEncodingException e) {
    					e.printStackTrace();
    				}
    			}
    			return result;
    			}
    		});
    	}
    	/**
    	 * 检查key是否已经存在
    	 * 
    	 * @param key
    	 * @return
    	 */
    	public boolean exists(final String key) {
    		return redisTemplate.execute(new RedisCallback<Boolean>() {
    			public Boolean doInRedis(RedisConnection connection)
    					throws DataAccessException {
    				return connection.exists(key.getBytes());
    			}
    			
    		});
    	}
    	/**
    	 * 清空redis 所有数据
    	 * 
    	 * @return
    	 */
    	public String flushDB() {
    		return redisTemplate.execute(new RedisCallback<String>() {
    			public String doInRedis(RedisConnection connection)
    					throws DataAccessException {
    				connection.flushDb();
    				return "success";
    			}
    		});
    	}
    	/**
    	 * 查看redis里有多少数据
    	 */
    	public long dbSize() {
    		return redisTemplate.execute(new RedisCallback<Long>() {
    			public Long doInRedis(RedisConnection connection)
    					throws DataAccessException {
    				return connection.dbSize();
    			}
    		});
    	}
    	/**
    	 * 检查是否连接成功
    	 * 
    	 * @return
    	 */
    	public String ping() {
    		return redisTemplate.execute(new RedisCallback<String>() {
    			public String doInRedis(RedisConnection connection)
    					throws DataAccessException {
    				return connection.ping();
    			}
    		});
    	}
    	/**
    	 * 设置key的生命周期
    	 * 
    	 * @param key
    	 * @param seconds
    	 *            单位(秒)
    	 * @return
    	 */
    	public boolean expire(final String key, final long seconds) {
    		return redisTemplate.execute(new RedisCallback<Boolean>() {
    			public Boolean doInRedis(RedisConnection connection)
    					throws DataAccessException {
    				return connection.expire(key.getBytes(), seconds);
    			}
    		});
    	}
    	/**
    	 * 自增长
    	 * 
    	 * @param key
    	 * @param length 增长步长
    	 * @return
    	 */
    	public long incr (final String key){
    		return redisTemplate.execute(new RedisCallback<Long>() {
    			public Long doInRedis(RedisConnection connection)
    					throws DataAccessException {
    				return connection.incr(key.getBytes());
    			}
    			
    		});
    	}
    	/**
    	 * 自增长
    	 * 
    	 * @param key
    	 * @param length 增长步长
    	 * @return
    	 */
    	public long incrBy (final String key, final long len){
    		return redisTemplate.execute(new RedisCallback<Long>() {
    			public Long doInRedis(RedisConnection connection)
    					throws DataAccessException {
    				return connection.incrBy(key.getBytes(), len);
    			}
    		});
    		
    	}
    	/**
    	 * 自增长
    	 * 
    	 * @param key
    	 * @param length 增长步长
    	 * @return
    	 */
    	public double incrBy (final String key, final double len){
    		return redisTemplate.execute(new RedisCallback<Double>() {
    			public Double doInRedis(RedisConnection connection)
    					throws DataAccessException {
    				return connection.incrBy(key.getBytes(), len);
    			}
    		});
    	}
    	
        public long eval(final String luaCommand) {
            return redisTemplate.execute(new RedisCallback<Long>() {
                public Long doInRedis(RedisConnection connection) throws DataAccessException {
                    return connection.eval(luaCommand.getBytes(), null,0);
                }
            });
        }
    
    }
    

      

    缓存应用:

    package com.eshore.ismp.cache.processor;
    
    import org.apache.log4j.Logger;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Service;
    import org.springframework.util.StringUtils;
    
    import com.alibaba.fastjson.JSON;
    import com.alibaba.fastjson.JSONObject;
    import com.eshore.ismp.cache.redis.RedisService;
    import com.eshore.ismp.common.entity.ResultInfo;
    
    /**
     * 
     * //DESC: 管理门户缓存接口
     * @author zzx
     * @date 2016年5月20日 上午11:50:25
     */
    @Service
    public class AdminWebProcessor {
    	private static final Logger logger = Logger.getLogger(AdminWebProcessor.class);
    	private static final String ADMINWEB_USER = "ADMINWEB_USER_";
    	private static final Long LIVETIME = 60*30L;
    	@Autowired
    	RedisService redisService;
    	
    	public String put(JSONObject param){
    		Long userId = param.getLong("user_id");
    		String userInfo = param.getString("user_info");
    		ResultInfo  rs = new ResultInfo();
    		if(userId==null || StringUtils.isEmpty(userInfo)){
    			logger.error("参数错误");
    			rs.setResult_code(2501);
    			rs.setResult_detail("参数错误");
    			return JSON.toJSONString(rs);
    		}
    		String key = ADMINWEB_USER+userId;
    		redisService.set(key , userInfo,LIVETIME);
    		rs.setResult_code(0);
    		rs.setResult_detail("success");
    		return JSON.toJSONString(rs);
    	}
    	
    	public String get(JSONObject param){
    		Long userId = param.getLong("user_id");
    		String key = ADMINWEB_USER+userId;
    		ResultInfo  rs = new ResultInfo();
    		String user = redisService.get(key);
    		rs.setResult_code(0);
    		rs.setResult_detail("success");
    		rs.setResult_data(user);
    		return JSON.toJSONString(rs);
    	}
    	
    	public String delete(JSONObject param){
    		Long userId = param.getLong("user_id");
    		String key = ADMINWEB_USER+userId;
    		ResultInfo  rs = new ResultInfo();
    		long isDel = redisService.del(key);
    		rs.setResult_code(0);
    		rs.setResult_detail("success");
    		return JSON.toJSONString(rs);
    	}
    
    }
    

      

      

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  • 原文地址:https://www.cnblogs.com/JAYIT/p/5647924.html
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