Jedis 使用入门

Redis 是一个开源的基于内存的数据结构存储，Redis 是远程字典服务（Remote Dictionary Server ）的简写，它通常被用作数据库，缓存，消息代理和流引擎。Redis提供的数据结构有string,hashes,lists,sets,sorted sets五种，Redis内置了复制,Lua脚本，LRU驱动事件,事务以及不同级别的磁盘持久方法。并提供了高可用的Redis 哨兵和Redis集群方案

1. Jedis是什么

Jedis 是 Redis 官方首选的 Java 客户端开发包， Jedis客户端同时支持单机模式、分片模式、集群模式的访问模式，通过构建Jedis类对象实现单机模式下的数据访问，通过构建ShardedJedis类对象实现分片模式的数据访问，通过构建JedisCluster类对象实现集群模式下的数据访问。

2. Jedis工作模式

Jedis主要有四大模块， Jedis,JedisCluster,JedisSentinel和ShardedJedis对应了Redis的四种工作模式

序号	模块	Redis模式
1	Jedis	Redis Standalone（单节点模式）
2	JedisCluster	Redis Cluster（集群模式）
3	JedisSentinel	Redis Sentinel（哨兵模式）
4	ShardedJedis	Redis Sharding（分片模式）

3. Jedis用例

依赖第三方包
jedis-2.7.2.jar 、commons-pool2-2.3.jar

JedisPoolManager用户管理数据库连接，比如获取或者释放

package com.redis.jedis.project.common;import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPool;
import redis.clients.jedis.JedisPoolConfig;public class JedisPoolManager {//private static String REDISDB_IP = "192.168.62.44";private static String REDISDB_IP = "127.0.0.1";private static int REDISDB_PORT = 6379;private JedisPool jedisPool;public JedisPoolManager() {JedisPoolConfig config = new JedisPoolConfig();config.setMaxTotal(20);config.setMaxIdle(5);config.setMaxWaitMillis(1000l);config.setTestOnBorrow(false);jedisPool = new JedisPool(config, REDISDB_IP, REDISDB_PORT);}public Jedis getJedis() throws Exception {try {Jedis jedis = jedisPool.getResource();return jedis;} catch (Exception e) {throw e;}}public void releaseJedis(Jedis jedis) {if (jedis != null) {jedis.close();}}
}

JedisManager 用户Redis数据库操作，当前只写了增删改查等常用行为

package com.redis.jedis.project.common;import java.util.Map;import redis.clients.jedis.Jedis;public class JedisManager {private JedisPoolManager pool = new JedisPoolManager();protected void set(int dbIndex, String key, String value, int cashSeconds)throws Exception {Jedis jedis = null;try {jedis = pool.getJedis();jedis.select(dbIndex);jedis.set(key, value);if (cashSeconds > 0) {jedis.expire(key, cashSeconds);}} catch (Exception e) {throw e;} finally {pool.releaseJedis(jedis);}}protected String get(int dbIndex, String key) throws Exception {Jedis jedis = null;try {jedis = pool.getJedis();jedis.select(dbIndex);return jedis.get(key);} catch (Exception e) {throw e;} finally {pool.releaseJedis(jedis);}}protected void delete(int dbIndex, String key) throws Exception {Jedis jedis = null;try {jedis = pool.getJedis();jedis.select(dbIndex);jedis.del(key);} catch (Exception e) {throw e;} finally {pool.releaseJedis(jedis);}}protected Map<String, String> hgetAll(int dbIndex, String key)throws Exception {Jedis jedis = null;try {jedis = pool.getJedis();jedis.select(dbIndex);return jedis.hgetAll(key);} catch (Exception e) {System.out.println(e);throw e;} finally {pool.releaseJedis(jedis);}}protected void hset(int dbIndex, String key, String field, String value)throws Exception {Jedis jedis = null;try {jedis = pool.getJedis();jedis.select(dbIndex);jedis.hset(key, field, value);} catch (Exception e) {throw e;} finally {pool.releaseJedis(jedis);}}protected void hmset(int dbIndex, String key, Map<String, String> maps,int cacheSeconds) throws Exception {Jedis jedis = null;try {jedis = pool.getJedis();jedis.select(dbIndex);jedis.hmset(key, maps);if (cacheSeconds >= 0) {jedis.expire(key, cacheSeconds);}} catch (Exception e) {throw e;} finally {pool.releaseJedis(jedis);}}protected void del(int dbIndex, String key) throws Exception {Jedis jedis = null;try {jedis = pool.getJedis();jedis.select(dbIndex);jedis.del(key);} catch (Exception e) {throw e;} finally {pool.releaseJedis(jedis);}}}

服务接口，实现具体业务，假设是登陆操作

package com.redis.jedis.project.common;public interface ILoginCash {public boolean longin(LoginDTO loginDTO,int cashSeconds) throws Exception;public LoginDTO getLogInfo(int userId) throws Exception;public boolean longout(int userId) throws Exception;}

package com.redis.jedis.project.common;import java.io.Serializable;public class LoginDTO implements Serializable {private static final long serialVersionUID = 1L;private int userId;private String code;private String name;private String ip;public int getUserId() {return userId;}public void setUserId(int userId) {this.userId = userId;}public String getCode() {return code;}public void setCode(String code) {this.code = code;}public String getName() {return name;}public void setName(String name) {this.name = name;}public String getIp() {return ip;}public void setIp(String ip) {this.ip = ip;}}

实现服务接口时，同时继承JedisManager管理类，这样可以使用JedisManager封装的操作数据库的行为，为了更好的方便管理KEY名称，一般Rredis中的KEY 都是由对象：ID 或者对象：ID:类型等结构管理的

package com.redis.jedis.project.common;import java.util.HashMap;
import java.util.Map;public class LoginCashManager extends JedisManager implements ILoginCash {private static final String REDIS_USER = "user";@Overridepublic boolean longin(LoginDTO loginDTO, int cashSeconds) throws Exception {boolean result = false;String key = REDIS_USER + ":" + loginDTO.getUserId();try {Map<String, String> map = new HashMap<String, String>();map.put("code", loginDTO.getCode());map.put("name", loginDTO.getName());map.put("ip", loginDTO.getIp());hmset(RedisDBConstants.USER_DB_INDEX, key, map, cashSeconds);result = true;} catch (Exception e) {System.out.println(e);}return result;}@Overridepublic LoginDTO getLogInfo(int userId) throws Exception {if (userId <= 0) {return null;}String key = REDIS_USER + ":" + userId;LoginDTO loginDTO = null;try {Map<String, String> map = hgetAll(RedisDBConstants.USER_DB_INDEX,key);if (map != null && !map.isEmpty()) {loginDTO = new LoginDTO();loginDTO.setUserId(userId);loginDTO.setCode(map.get("code"));loginDTO.setName(map.get("name"));loginDTO.setIp(map.get("ip"));}} catch (Exception e) {System.out.println(e);}return loginDTO;}@Overridepublic boolean longout(int userId) throws Exception {if (userId <= 0) {return false;}String tokenKey = REDIS_USER + ":" + userId;boolean result = false;try {del(RedisDBConstants.USER_DB_INDEX, tokenKey);result = true;} catch (Exception e) {System.out.println(e);}return result;}}

Redis默认有16个库，分别由数字 0到15编号，为方便管理，可以通过名称定义的方式以便查找

package com.redis.jedis.project.common;public class RedisDBConstants {public static int SYS_DB_INDEX = 0;public static int USER_DB_INDEX = 1;
}

测试类

package com.redis.jedis.project.common;public class MainTestRedis {public static void main(String[] args) throws Exception {LoginCashManager logincash = new LoginCashManager();System.out.println("==SAVE NOW==");LoginDTO loginDTO = new LoginDTO();loginDTO.setUserId(1000);loginDTO.setCode("1003");loginDTO.setName("LIUY");loginDTO.setIp("127.0.0.1");logincash.longin(loginDTO,50);System.out.println("==SAVE END==");LoginDTO login =logincash.getLogInfo(1000);System.out.println("==GET INFO==");System.out.println("id="+login.getUserId());System.out.println("code="+login.getCode());System.out.println("name="+login.getName());System.out.println("loginIP="+login.getIp());}
}

打印测试结果

==SAVE NOW==
==SAVE END==
==GET INFO==
id=1000
code=1003
name=LIUY
loginIP=127.0.0.1