问题描叙

出现这种乱码前缀的原因是没有进行序列化，因此导致在传输过程出现乱码问题，存到数据库，发现 key,hash key/value 都有 \xAC\xED\x00\x05t\x00 前缀。RedisTemplate类中默认是没有设置序列化的。

解决方法

设置RedisTemplate的序列化方式

import com.fasterxml.jackson.annotation.JsonAutoDetect;
import com.fasterxml.jackson.annotation.PropertyAccessor;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.context.annotation.Bean;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;
 
public class RedisConfig {
    @Bean(name = "redisTemplate")
    //配置redisTemplate
    //默认情况下redisTemplate只能支持redisTemplate<String,String>
    //需要自定义 RedisTemplate,设置序列化
    public RedisTemplate<String,Object> redisTemplate(RedisConnectionFactory factory){
        RedisTemplate<String,Object> template = new RedisTemplate <>();
        template.setConnectionFactory(factory);
 
        Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class);
        ObjectMapper om = new ObjectMapper();
        om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
        om.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);
        jackson2JsonRedisSerializer.setObjectMapper(om);
 
        StringRedisSerializer stringRedisSerializer = new StringRedisSerializer();
        // key采用String的序列化方式
        template.setKeySerializer(stringRedisSerializer);
        // hash的key也采用String的序列化方式
        template.setHashKeySerializer(stringRedisSerializer);
        // value序列化方式采用jackson
        template.setValueSerializer(jackson2JsonRedisSerializer);
        // hash的value序列化方式采用jackson
        template.setHashValueSerializer(jackson2JsonRedisSerializer);
        template.afterPropertiesSet();
        return template;
    }
}

注意：用了StringRedisSerializer之后，redis库的数据都是以String类型保存，所以int类型的整数，在保存时，会类型上升， 先变成double，然后再存成String，也就是1会存成"1.0"，所以如果保存int数据时，需要自己在代码中单独处理下。上面修改全局配置不能兼容新老数据，新增配置可以兼容。

修改序列化方式后，数据不兼容报错

org.springframework.data.redis.serializer.SerializationException: Cannot deserialize; nested exception is org.springframework.core.serializer.support.SerializationFailedException: Failed to deserialize payload. Is the byte array a result of corresponding serialization for DefaultDeserializer?; nested exception is java.io.StreamCorruptedException: invalid stream header: E5A487E6

使用多个redisTemplate配置

@Configuration
public class RedisConfig {

    @Bean
    @Primary
    public RedisTemplate redisTemplate(RedisConnectionFactory connectionFactory) {
        RedisTemplate redisTemplate = new RedisTemplate<>();
        redisTemplate.setConnectionFactory(connectionFactory);
        redisTemplate.setKeySerializer(new StringRedisSerializer());
        redisTemplate.setValueSerializer(new StringRedisSerializer());
        redisTemplate.setHashKeySerializer(new StringRedisSerializer());
        redisTemplate.setHashValueSerializer(new StringRedisSerializer());
        return redisTemplate;
    }

    @Bean(name = "ByteRedisTemplate")
    public RedisTemplate ByteRedisTemplate(
            RedisConnectionFactory redisConnectionFactory) {
        RedisTemplate<String, Object> redisTemplate = new RedisTemplate<>();
        redisTemplate.setConnectionFactory(redisConnectionFactory);
        redisTemplate.setKeySerializer(new StringRedisSerializer());
        redisTemplate.setValueSerializer(RedisSerializer.byteArray());
        redisTemplate.setHashKeySerializer(new StringRedisSerializer());
        redisTemplate.setHashValueSerializer(RedisSerializer.byteArray());
        return redisTemplate;
    }
}

使用方法 

@RestController
public class PublishDemo {

    @Autowired
    private RedisTemplate redisTemplate;

    @Autowired
    @Qualifier("ByteRedisTemplate")
    private RedisTemplate byteRedisTemplate;

    @RequestMapping("set")
    public void set() {
        String key1 = "t1";
        String value = "12345";
        String key2 = "t2";
        String value2 = "54321";
        redisTemplate.opsForValue().set(key1, value);
        byteRedisTemplate.opsForValue().set(key2, value2.getBytes());
    }

    @RequestMapping("get")
    public void get() {
        Object t1 = redisTemplate.opsForValue().get("t1");
        System.out.println("t1:" + t1.toString());
        Object o = byteRedisTemplate.opsForValue().get("t2");
        System.out.println("t2:" + Arrays.toString((byte[]) o));
    }
}

对象存hash

entityMap.forEach((field, value) -> redisTemplate.opsForHash().put(String.format(REDIS_CONN_KEY, entity.getId()), field, value != null ? String.valueOf(value) : ""));