在 Spring 项目中，如何实现对 Redis 的操作？

在 Spring 项目里实现对 Redis 的操作，可借助 Spring Data Redis 这一强大工具。下面会详细介绍实现步骤并给出示例代码。

1. 添加依赖

若使用 Maven 项目，需在 pom.xml 中添加如下依赖：

<dependencies>
    <!-- Spring Data Redis -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-redis</artifactId>
    </dependency>
    <!-- Lettuce 连接池 -->
    <dependency>
        <groupId>org.apache.commons</groupId>
        <artifactId>commons-pool2</artifactId>
    </dependency>
</dependencies>

这里添加了 Spring Data Redis 依赖，同时引入了 Lettuce 连接池依赖。

2. 配置 Redis

在 application.properties 或者 application.yml 文件中配置 Redis 的连接信息。

application.properties 示例

spring.redis.host=localhost
spring.redis.port=6379
spring.redis.password=
spring.redis.lettuce.pool.max-active=8
spring.redis.lettuce.pool.max-idle=8
spring.redis.lettuce.pool.min-idle=0
spring.redis.lettuce.pool.max-wait=-1ms

application.yml 示例

spring:
  redis:
    host: localhost
    port: 6379
    password:
    lettuce:
      pool:
        max-active: 8
        max-idle: 8
        min-idle: 0
        max-wait: -1ms

3. 创建 Redis 配置类

可以创建一个配置类，对 RedisTemplate 进行自定义配置：

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.GenericJackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;

@Configuration
public class RedisConfig {

    @Bean
    public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory redisConnectionFactory) {
        RedisTemplate<String, Object> template = new RedisTemplate<>();
        template.setConnectionFactory(redisConnectionFactory);
        template.setKeySerializer(new StringRedisSerializer());
        template.setValueSerializer(new GenericJackson2JsonRedisSerializer());
        template.setHashKeySerializer(new StringRedisSerializer());
        template.setHashValueSerializer(new GenericJackson2JsonRedisSerializer());
        template.afterPropertiesSet();
        return template;
    }
}

此配置类将 Redis 的键和哈希键序列化为字符串，值和哈希值序列化为 JSON 格式。

4. 编写 Redis 操作服务类

创建一个服务类，用于封装 Redis 的常用操作：

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.stereotype.Service;

import java.util.concurrent.TimeUnit;

@Service
public class RedisService {

    @Autowired
    private RedisTemplate<String, Object> redisTemplate;

    /**
     * 设置键值对
     * @param key 键
     * @param value 值
     */
    public void set(String key, Object value) {
        redisTemplate.opsForValue().set(key, value);
    }

    /**
     * 设置键值对并指定过期时间
     * @param key 键
     * @param value 值
     * @param timeout 过期时间
     * @param unit 时间单位
     */
    public void set(String key, Object value, long timeout, TimeUnit unit) {
        redisTemplate.opsForValue().set(key, value, timeout, unit);
    }

    /**
     * 获取键对应的值
     * @param key 键
     * @return 值
     */
    public Object get(String key) {
        return redisTemplate.opsForValue().get(key);
    }

    /**
     * 删除键
     * @param key 键
     * @return 是否删除成功
     */
    public boolean delete(String key) {
        return redisTemplate.delete(key);
    }
}

5. 使用 Redis 操作服务类

在控制器或者服务类中注入 RedisService 并使用：

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.concurrent.TimeUnit;

@RestController
@RequestMapping("/redis")
public class RedisController {

    @Autowired
    private RedisService redisService;

    @GetMapping("/set")
    public String setValue() {
        redisService.set("testKey", "testValue", 60, TimeUnit.SECONDS);
        return "Value set successfully";
    }

    @GetMapping("/get")
    public Object getValue() {
        return redisService.get("testKey");
    }

    @GetMapping("/delete")
    public String deleteValue() {
        boolean result = redisService.delete("testKey");
        return result ? "Value deleted successfully" : "Value deletion failed";
    }
}

以下是完整的代码示例，包含了上述步骤中的关键代码：

pom.xml

<dependencies>
    <!-- Spring Data Redis -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-redis</artifactId>
    </dependency>
    <!-- Lettuce 连接池 -->
    <dependency>
        <groupId>org.apache.commons</groupId>
        <artifactId>commons-pool2</artifactId>
    </dependency>
</dependencies>    

application.properties

spring.redis.host=localhost
spring.redis.port=6379
spring.redis.password=
spring.redis.lettuce.pool.max-active=8
spring.redis.lettuce.pool.max-idle=8
spring.redis.lettuce.pool.min-idle=0
spring.redis.lettuce.pool.max-wait=-1ms

RedisConfig.java

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.GenericJackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;

@Configuration
public class RedisConfig {

    @Bean
    public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory redisConnectionFactory) {
        RedisTemplate<String, Object> template = new RedisTemplate<>();
        template.setConnectionFactory(redisConnectionFactory);
        template.setKeySerializer(new StringRedisSerializer());
        template.setValueSerializer(new GenericJackson2JsonRedisSerializer());
        template.setHashKeySerializer(new StringRedisSerializer());
        template.setHashValueSerializer(new GenericJackson2JsonRedisSerializer());
        template.afterPropertiesSet();
        return template;
    }
}    

RedisService.java

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.stereotype.Service;

import java.util.concurrent.TimeUnit;

@Service
public class RedisService {

    @Autowired
    private RedisTemplate<String, Object> redisTemplate;

    /**
     * 设置键值对
     * @param key 键
     * @param value 值
     */
    public void set(String key, Object value) {
        redisTemplate.opsForValue().set(key, value);
    }

    /**
     * 设置键值对并指定过期时间
     * @param key 键
     * @param value 值
     * @param timeout 过期时间
     * @param unit 时间单位
     */
    public void set(String key, Object value, long timeout, TimeUnit unit) {
        redisTemplate.opsForValue().set(key, value, timeout, unit);
    }

    /**
     * 获取键对应的值
     * @param key 键
     * @return 值
     */
    public Object get(String key) {
        return redisTemplate.opsForValue().get(key);
    }

    /**
     * 删除键
     * @param key 键
     * @return 是否删除成功
     */
    public boolean delete(String key) {
        return redisTemplate.delete(key);
    }
}    

RedisController.java

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.concurrent.TimeUnit;

@RestController
@RequestMapping("/redis")
public class RedisController {

    @Autowired
    private RedisService redisService;

    @GetMapping("/set")
    public String setValue() {
        redisService.set("testKey", "testValue", 60, TimeUnit.SECONDS);
        return "Value set successfully";
    }

    @GetMapping("/get")
    public Object getValue() {
        return redisService.get("testKey");
    }

    @GetMapping("/delete")
    public String deleteValue() {
        boolean result = redisService.delete("testKey");
        return result ? "Value deleted successfully" : "Value deletion failed";
    }
}    

通过上述步骤，你就能在 Spring 项目里实现对 Redis 的基本操作。你可以依据需求对 RedisService 类进行扩展，以实现更丰富的 Redis 操作。