整合Springboot + Redis

使用Springboot快速整合Redis，Redisson

1.导入Redis相关依赖

<!--     Redis-->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>
<!-- https://github.com/redisson/redisson#quick-start -->
<dependency>
    <groupId>org.redisson</groupId>
    <artifactId>redisson</artifactId>
    <version>3.17.5</version>
</dependency>

2. 在Springboot配置文件中配置Redis连接

#  Redis
  redis:
    host: ServerUrl
    port: 
    password: 
    lettuce:
      pool:
        max-active: 8
        max-idle: 8
        max-wait: -1ms
        min-idle: 0
    timeout: 3000
    database: 0 # 指定几号数据库

3. 配置RedisTemplate

数据传输过程中涉及序列化问题，如果不主动指定序列化器，可能会发生因为序列化不同而造成的问题（乱码或直接报错）。

/**
 * Redis配置类
 *
 * @author gaffey
 *
 */
@Configuration
public class RedisConfig {

  @Bean
  public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory connectionFactory) {
    RedisTemplate<String, Object> template = new RedisTemplate<>();
    template.setConnectionFactory(connectionFactory);

    //string
    template.setKeySerializer(new StringRedisSerializer());
    template.setValueSerializer(new GenericJackson2JsonRedisSerializer());
    //Hash
    template.setHashKeySerializer(new StringRedisSerializer());
    template.setHashValueSerializer(new GenericJackson2JsonRedisSerializer());
    template.setDefaultSerializer(new GenericJackson2JsonRedisSerializer());
    return template;
  }
}

3.配置Redisson连接

Redisson可以看作是一个Redis的客户端，是封装了的框架。可以按照Java的语法习惯直接操作Redis。同时它还实现了分布式锁框架，可使用Redisson实现分布式锁。

/**
 * Redisson配置类
 *
 * @author GaffEy
 */
@Configuration
@ConfigurationProperties(prefix = "spring.redis")
@Data
public class RedissionConfig {

    private String host;
    private String port;

    @Bean
    public RedissonClient redissonClient() {
        // 1. 创建配置
        Config config = new Config();
        String redisAddress = String.format("redis://%s:%s", host, port);
        config.useSingleServer()
                .setPassword("password") // 即auth password
                .setAddress(redisAddress)
                .setDatabase(3);
        // 2. 创建实例
        RedissonClient redisson = Redisson.create(config);
        return redisson;
    }
}

Redis + Lua脚本

// Lua脚本
private static final String luaScript = "local zsetKey = KEYS[1]\n" +
    "local attractionName = ARGV[1]\n" +
    "local decreasedScore = tonumber(ARGV[2])\n" +
    "redis.call('ZREM', zsetKey, attractionName)\n" +
    "redis.call('ZADD', zsetKey, decreasedScore, attractionName)\n" +
    "return 'True'";

    public void decreaseHot(){
        List<String> attractionNameList = attractionMapper.selectAttractionName();
        Set<ZSetOperations.TypedTuple<Object>> tuples = redisTemplate.opsForZSet().rangeWithScores(RedisUtils.ZSET_KEY, 0, -1);
        for (ZSetOperations.TypedTuple<Object> tuple:tuples){
            String attractionName = tuple.getValue().toString();
            Double score = Double.valueOf(tuple.getScore().toString());
            Double decreasedScore = score * 0.8;
            String newScore = String.valueOf(decreasedScore);
            RedisScript<Object> script = new DefaultRedisScript<>(luaScript, Object.class);
            stringRedisTemplate.execute(script, Collections.singletonList(RedisUtils.ZSET_KEY),attractionName,newScore);
        }
    }

使用Lua脚本时一定要注意序列化问题，通过Lua脚本存入，存入的Value是通过 new StringRedisSerializer()序列化器序列化为字符串类型。注意自己RedisTmplae配置的ValueSerializer()要配置成StringRedisSerializer()，否则传输数据会出错。

最好的方法是单独配置一个RedisTemplate