1. 在Java中操作Redis

1.1 Redis的Java客戶端

Redis 的 Java 客戶端很多，常用的幾種：

• Jedis
• Lettuce
• Spring Data Redis

Spring 對 Redis 客戶端進行了整合，提供了 Spring Data Redis，在Spring Boot項目中還提供了對應的Starter，即 spring-boot-starter-data-redis

1.2 Spring Data Redis使用方式

1.2.1 介紹

Spring Data Redis 是 Spring 的一部分，提供了在 Spring 應用中通過簡單的配置就可以訪問 Redis 服務，對 Redis 底層開發包進行了高度封裝。在 Spring 項目中，可以使用Spring Data Redis來簡化 Redis 操作。

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

Spring Boot提供了對應的Starter，maven坐標：

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

Spring Data Redis中提供了一個高度封裝的類：RedisTemplate，對相關api進行了歸類封裝,將同一類型操作封裝為operation接口，具體分類如下：

• ValueOperations：string數據操作
• SetOperations：set類型數據操作
• ZSetOperations：zset類型數據操作
• HashOperations：hash類型的數據操作
• ListOperations：list類型的數據操作

1.2.1 環境搭建

1). 導入Spring Data Redis的maven坐標

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

2). 配置Redis數據源

在application-dev.yml中添加

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

解釋說明：

database:指定使用Redis的哪個數據庫，Redis服務啟動后默認有16個數據庫，編號分別是從0到15。

可以通過修改Redis配置文件來指定數據庫的數量。

3). 編寫配置類，創建RedisTemplate對象

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("開始創建redis模板對象");RedisTemplate redisTemplate = new RedisTemplate();// 設置redis的連接工廠對象redisTemplate.setConnectionFactory(redisConnectionFactory);// 設置redis key的序列化器redisTemplate.setKeySerializer(new StringRedisSerializer());return redisTemplate;}
}

解釋說明：

當前配置類不是必須的，因為 Spring Boot 框架會自動裝配 RedisTemplate 對象，但是默認的key序列化器為

JdkSerializationRedisSerializer，導致我們存到Redis中后的數據和原始數據有差別，故設置為

StringRedisSerializer序列化器。

4). 通過RedisTemplate對象操作Redis

在test下新建測試類

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操作類型ValueOperations valueOperations = redisTemplate.opsForValue();// hash操作類型HashOperations hashOperations = redisTemplate.opsForHash();// list操作類型ListOperations listOperations = redisTemplate.opsForList();// set操作類型SetOperations setOperations = redisTemplate.opsForSet();// zet操作類型ZSetOperations zSetOperations = redisTemplate.opsForZSet();}

1.2.3 操作常見類型數據

1). 操作字符串類型數據

@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). 操作列表類型數據

@Testpublic void testRedisList(){// lpush lrange rpop llenListOperations listOperations = redisTemplate.opsForList();listOperations.leftPush("list", "a");listOperations.leftPushAll("list", "b", "c", "d" );  // 依次入棧，棧頂為右邊，棧底為左邊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). 操作哈希類型數據

 // 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). 操作集合類型數據

@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). 操作有序集合類型數據

@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");}