1. 在Java中操作Redis

1.1 Redis的Java客户端

Redis 的 Java 客户端很多，常用的几种：

• Jedis
• Lettuce
• Spring Data Redis

Spring 对 Redis 客户端进行了整合，提供了 Spring Data Redis，在Spring Boot项目中还提供了对应的Starter，即 spring-boot-starter-data-redis

1.2 Spring Data Redis使用方式

1.2.1 介绍

Spring Data Redis 是 Spring 的一部分，提供了在 Spring 应用中通过简单的配置就可以访问 Redis 服务，对 Redis 底层开发包进行了高度封装。在 Spring 项目中，可以使用Spring Data Redis来简化 Redis 操作。

网址：https://spring.io/projects/spring-data-redis

Spring Boot提供了对应的Starter，maven坐标：

<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>

Spring Data Redis中提供了一个高度封装的类：RedisTemplate，对相关api进行了归类封装,将同一类型操作封装为operation接口，具体分类如下：

• ValueOperations：string数据操作
• SetOperations：set类型数据操作
• ZSetOperations：zset类型数据操作
• HashOperations：hash类型的数据操作
• ListOperations：list类型的数据操作

1.2.1 环境搭建

1). 导入Spring Data Redis的maven坐标

<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>

2). 配置Redis数据源

在application-dev.yml中添加

sky:redis:host: localhostport: 6379password: 123456database: 10

解释说明：

database:指定使用Redis的哪个数据库，Redis服务启动后默认有16个数据库，编号分别是从0到15。

可以通过修改Redis配置文件来指定数据库的数量。

3). 编写配置类，创建RedisTemplate对象

package com.sky.config;import lombok.extern.slf4j.Slf4j;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.serializer.StringRedisSerializer;@Configuration
@Slf4j
public class RedisConfiguration {@Beanpublic RedisTemplate redisTemplate(RedisConnectionFactory redisConnectionFactory){log.info("开始创建redis模板对象");RedisTemplate redisTemplate = new RedisTemplate();// 设置redis的连接工厂对象redisTemplate.setConnectionFactory(redisConnectionFactory);// 设置redis key的序列化器redisTemplate.setKeySerializer(new StringRedisSerializer());return redisTemplate;}
}

解释说明：

当前配置类不是必须的，因为 Spring Boot 框架会自动装配 RedisTemplate 对象，但是默认的key序列化器为

JdkSerializationRedisSerializer，导致我们存到Redis中后的数据和原始数据有差别，故设置为

StringRedisSerializer序列化器。

4). 通过RedisTemplate对象操作Redis

在test下新建测试类

package com.sky.test;import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.data.redis.connection.DataType;
import org.springframework.data.redis.core.*;import java.util.List;
import java.util.Set;
import java.util.concurrent.TimeUnit;@SpringBootTest
public class SpringRedisTest {@AutowiredRedisTemplate redisTemplate;@Testpublic void testRedisTemplate(){// string操作类型ValueOperations valueOperations = redisTemplate.opsForValue();// hash操作类型HashOperations hashOperations = redisTemplate.opsForHash();// list操作类型ListOperations listOperations = redisTemplate.opsForList();// set操作类型SetOperations setOperations = redisTemplate.opsForSet();// zet操作类型ZSetOperations zSetOperations = redisTemplate.opsForZSet();}

1.2.3 操作常见类型数据

1). 操作字符串类型数据

@Testpublic void testRedisString(){// set, get, setex, setnxValueOperations valueOperations = redisTemplate.opsForValue();valueOperations.set("name", "lsm");String name = (String) valueOperations.get("name");System.out.println(name);valueOperations.set("code", "1234", 3, TimeUnit.MINUTES);valueOperations.setIfAbsent("lock", 1);valueOperations.setIfAbsent("lock", 2);System.out.println(valueOperations.get("lock"));}

2). 操作列表类型数据

@Testpublic void testRedisList(){// lpush lrange rpop llenListOperations listOperations = redisTemplate.opsForList();listOperations.leftPush("list", "a");listOperations.leftPushAll("list", "b", "c", "d" );  // 依次入栈，栈顶为右边，栈底为左边String tmp = (String) listOperations.leftPop("list");System.out.println("tmp: " + tmp);  // tmp: dLong size = listOperations.size("list");System.out.println("size: " + size);List list = listOperations.range("list", 0, -1);System.out.println("list: " + list); // list: [c, b, a]}

3). 操作哈希类型数据

 // hset hget hdel hkeys hvalsHashOperations hashOperations = redisTemplate.opsForHash();hashOperations.put("key_1", "name", "lsm");hashOperations.put("key_1", "age", "20");hashOperations.put("key_1", "sex", "男");String name = (String) hashOperations.get("key_1", "name");System.out.println("name: " + name); // name: lsmLong delete = hashOperations.delete("key_1", "sex");System.out.println("delete: " + delete); // delete: 1Set key_1 = hashOperations.keys("key_1");System.out.println("key_1: " + key_1); // key_1: [name, age]List key_2 = hashOperations.values("key_1");System.out.println("key_2: " + key_2);  // key_2: [lsm, 20]}

4). 操作集合类型数据

@Testpublic void testRedisSet() {// sadd smembers scard sinter sunion sremSetOperations setOperations = redisTemplate.opsForSet();setOperations.add("set1", "a", "b", "c", "d");setOperations.add("set1", "e");Set set1 = setOperations.members("set1");System.out.println("set1: " + set1);  // set1: [a, d, c, b, e]Long size = setOperations.size("set1");System.out.println("size: " + size); // size = 5setOperations.remove("set1", "e");setOperations.add("set2", "a", "b", "x", "y");Set intersect = setOperations.intersect("set1", "set2");System.out.println("intersect: " + intersect);  // intersect: [a, b]Set union = setOperations.union("set1", "set2");System.out.println("union: " + union);  // union: [a, x, b, d, y, c]}

5). 操作有序集合类型数据

@Testpublic void testRedisZset() {// zadd zrange zincrby zremZSetOperations zSetOperations = redisTemplate.opsForZSet();zSetOperations.add("zset", "a", 10);zSetOperations.add("zset", "b", 15);zSetOperations.add("zset", "c", 12);Set zset1 = zSetOperations.range("zset", 0, -1);System.out.println("zset1: " + zset1); // zset1: [a, c, b]zSetOperations.incrementScore("zset", "c", 10);zSetOperations.remove("zset", "a", "b");}

6). 通用命令操作

// keys exists type delSet keys = redisTemplate.keys("*");System.out.println("keys: " + keys);  // keys: [list, key_1, set1, zset, set2]Boolean name = redisTemplate.hasKey("name");Boolean set1 = redisTemplate.hasKey("set1");System.out.println("name: " + name);  // name: falseSystem.out.println("set1: " + set1);  // set1: truefor(Object key : keys){DataType type = redisTemplate.type(key);System.out.println(type);}redisTemplate.delete("list");}