Spring Boot 项目中的 Redis 初体验：配置、工具类封装与实战应用

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

spring:
  redis:
    host: localhost
    port: 6379
    password: your_password # 如果没有密码则省略此配置项
    timeout: 60000
    jedis:
      pool:
        max-active: 8
        max-wait: -1
        max-idle: 8
        min-idle: 0

@Configuration
public class RedisConfig {

    @Bean
    public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory factory) {
        RedisTemplate<String, Object> template = new RedisTemplate<>();
        template.setConnectionFactory(factory);
        
        // 使用 Jackson2JsonRedisSerializer 来序列化和反序列化 Redis 的值
        Jackson2JsonRedisSerializer<Object> serializer = new Jackson2JsonRedisSerializer<Object>(Object.class);

        ObjectMapper mapper = new ObjectMapper();
        mapper.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
        mapper.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);
        serializer.setObjectMapper(mapper);
        
        template.setValueSerializer(serializer);
        template.setKeySerializer(new StringRedisSerializer());
        template.afterPropertiesSet();

        return template;
    }

    @Bean
    public RedisConnectionFactory redisConnectionFactory() {
        RedisStandaloneConfiguration configuration = new RedisStandaloneConfiguration();
        configuration.setHostName("localhost");
        configuration.setPort(6379);
        configuration.setPassword(RedisPassword.of("your_password")); // 如果没有密码则省略此配置项

        return new LettuceConnectionFactory(configuration);
    }
}

@Component
public class RedisUtil {

    @Autowired
    private StringRedisTemplate stringRedisTemplate;

    // 设置字符串值
    public void set(String key, String value) {
        stringRedisTemplate.opsForValue().set(key, value);
    }

    // 获取字符串值
    public String get(String key) {
        return stringRedisTemplate.opsForValue().get(key);
    }

    // 设置字符串值并设置过期时间（单位：秒）
    public void setWithExpire(String key, String value, long timeout) {
        stringRedisTemplate.opsForValue().set(key, value, timeout, TimeUnit.SECONDS);
    }

    // 判断键是否存在
    public boolean hasKey(String key) {
        return stringRedisTemplate.hasKey(key);
    }

    // 删除键
    public void delete(String key) {
        stringRedisTemplate.delete(key);
    }

    // 其他操作，如 List、Set、Hash 等操作可以类似地封装
}

@Service
public class UserService {

    @Autowired
    private RedisUtil redisUtil;

    public void addUser(String username) {
        // 检查用户名是否已存在
        if (redisUtil.hasKey(username)) {
            throw new RuntimeException("用户名已存在");
        }

        // 将新用户添加到数据库
        // ...

        // 将用户名存储到 Redis 中
        redisUtil.set(username, "1");
    }

    public void deleteUser(String username) {
        // 从数据库中删除用户
        // ...

        // 从 Redis 中删除用户名
        redisUtil.delete(username);
    }

    public boolean checkUserExist(String username) {
        return redisUtil.hasKey(username);
    }
}

spring:
  cache:
    type: redis
    redis:
      cache:
        time-to-live: 3600000 # 设置缓存的过期时间，单位为毫秒

@Service
public class UserService {

    @Cacheable(value = "users", key = "#id")
    public User getUserById(Long id) {
        // 模拟从数据库中查询用户信息
        return new User(id, "User" + id, 20 + id);
    }
}

spring:
  session:
    store-type: redis
    redis:
      namespace: spring:session:sessions

@SpringBootApplication
@EnableRedisHttpSession
public class Application {
    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}