解决办法：添加 redis 配置类，配置使用的序列化方式
@Configuration
public class RedisConfig {
 
    @Bean(name = "redisTemplate")
    public RedisTemplate<Object, Object> redisTemplate(RedisConnectionFactory factory) {
        RedisTemplate<Object, Object> template = new RedisTemplate<>();
        RedisSerializer<String> redisSerializer = new StringRedisSerializer();
 
        template.setConnectionFactory(factory);
        //key序列化方式
        template.setKeySerializer(redisSerializer);
        //value序列化
        template.setValueSerializer(redisSerializer);
        //value hashmap序列化
        template.setHashValueSerializer(redisSerializer);
        //key haspmap序列化
        template.setHashKeySerializer(redisSerializer);
        
        return template;
    }
}

@Autowired
private RedisTemplate<String,String> redisTemplate;

                        
原文链接：https://blog.csdn.net/m4330187/article/details/108091447