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Java 中常用缓存Cache机制的实现

时间:2016-07-06 20:18:17      阅读:291      评论:0      收藏:0      [点我收藏+]

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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。

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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);
	}

}

  

  

Java 中常用缓存Cache机制的实现

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

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