SpringBoot整合Mybatis-plus和Redis实现投票功能

spring:
  # Redis相关配置
  redis:
    # Redis服务器IP地址
    host: localhost
    # Redis服务器端口号
    port: 6379
    # Redis服务器密码
    password: 
    # Redis连接池最大连接数
    jedis:
      pool:
        max-active: 8
    # Redis连接池最大等待时间（单位：毫秒）
    lettuce:
      pool:
        max-wait: -1ms
    timeout: 5000ms

@Configuration
@MapperScan("com.example.mapper")
public class MybatisPlusConfig {
    /**
     * Mybatis-plus分页插件配置
     */
    @Bean
    public PaginationInterceptor paginationInterceptor() {
        return new PaginationInterceptor();
    }
    /**
     * Mybatis-plus通用Mapper配置
     */
    @Bean
    public MapperScannerConfigurer mapperScannerConfigurer() {
        MapperScannerConfigurer scannerConfigurer = new MapperScannerConfigurer();
        scannerConfigurer.setSqlSessionFactoryBeanName("sqlSessionFactory");
        scannerConfigurer.setBasePackage("com.example.mapper");
        return scannerConfigurer;
    }
}

@Data
@AllArgsConstructor
@NoArgsConstructor
public class Vote implements Serializable {
    private Long id;
    private Integer count;
}

CREATE TABLE `vote` (
  `id` bigint(20) NOT NULL,
  `count` int(11) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

public interface VoteMapper extends BaseMapper<Vote> {
    /**
     * 增加投票数
     * @param id 投票项id
     * @return
     */
    int increaseCount(@Param("id") Long id);
    /**
     * 查询投票数
     * @param id 投票项id
     * @return
     */
    int selectCount(@Param("id") Long id);
}

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
  "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.example.mapper.VoteMapper">
    <!-- 增加投票数 -->
    <update id="increaseCount">
        update vote set count = count + 1
        where id = #{id}
    </update>
    <!-- 查询投票数 -->
    <select id="selectCount" resultType="int">
        select count
        from vote
        where id = #{id}
    </select>
</mapper>

@Service
public class VoteService {
    @Autowired
    private VoteMapper voteMapper;
    @Autowired
    private RedisTemplate<String, Object> redisTemplate;
    /**
     ** @param id 投票项id
     */
    public void increaseCount(Long id) {
        ValueOperations<String, Object> operations = redisTemplate.opsForValue();
        String key = "vote:" + id;
        // 先从缓存中获取投票数
        Integer count = (Integer) operations.get(key);
        // 如果缓存中没有，则从数据库中获取，并存入缓存
        if (count == null) {
            count = voteMapper.selectCount(id);
            if (count != null) {
                operations.set(key, count);
            }
        }
        // 如果缓存中有，则增加投票数并更新缓存
        if (count != null) {
            operations.increment(key);
            voteMapper.increaseCount(id);
        }
    }
    /**
     * 查询投票数
     * @param id 投票项id
     * @return
     */
    public Integer selectCount(Long id) {
        ValueOperations<String, Object> operations = redisTemplate.opsForValue();
        String key = "vote:" + id;
        // 先从缓存中获取投票数
        Integer count = (Integer) operations.get(key);
        // 如果缓存中没有，则从数据库中获取，并存入缓存
        if (count == null) {
            count = voteMapper.selectCount(id);
            if (count != null) {
                operations.set(key, count);
            }
        }
        return count;
    }
}

@RestController
public class VoteController {
    @Autowired
    private VoteService voteService;
    /**
     * 增加投票数接口
     * @param id 投票项id
     * @return
     */
    @PostMapping("/vote/increase")
    public String increaseCount(@RequestParam Long id) {
        voteService.increaseCount(id);
        return "success";
    }
    /**
     * 查询投票数接口
     * @param id 投票项id
     * @return
     */
    @GetMapping("/vote/select")
    public Integer selectCount(@RequestParam Long id) {
        Integer count = voteService.selectCount(id);
        return count == null ? 0 : count;
    }
}