redis初学者常见字符乱码问题及解决办法

本文开发环境介绍

开发依赖	版本
Spring Boot	2.6.6

pom.xml依赖

<dependencies>
    <dependency>
        <groupId>org.springframework.bootgroupId>
        <artifactId>spring-boot-starter-data-redisartifactId>
    dependency>
    <dependency>
        <groupId>redis.clientsgroupId>
        <artifactId>jedisartifactId>
    dependency>
    <dependency>
        <groupId>com.fasterxml.jackson.coregroupId>
        <artifactId>jackson-databindartifactId>
    dependency>
dependencies>

redis保存数据后出现\xac\xed\x00\x05t\x00的问题

测试代码

public class RedisTemplateTest extends DemoRedisTestBase {

    @SneakyThrows
    @Test
    void testSet() {
        String key = String.join(":", "user", RandomStringUtils.randomAlphabetic(10));
        Map<String, String> value = new HashMap<>();
        value.put("id", RandomStringUtils.randomAlphabetic(10));
        value.put("name", RandomStringUtils.randomAlphabetic(10));
        redisTemplate.opsForValue().set(key, objectMapper.writeValueAsString(value));
    }
}

查看写入redis的数据

127.0.0.1:6379> keys *user*
1) "\xac\xed\x00\x05t\x00\x0fuser:mnaurYPzBt"

这是因为默认把key和value的值序列化成**byte[]**格式。

解决办法

@Configuration
public class RedisTemplateBeanPostProcessor implements BeanPostProcessor {

    @Override
    public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
        if(RedisTemplate.class.isAssignableFrom(bean.getClass())) {
            RedisTemplate redisTemplate = (RedisTemplate)bean;
            StringRedisSerializer stringRedisSerializer = new StringRedisSerializer();
            redisTemplate.setKeySerializer(stringRedisSerializer);
            redisTemplate.setValueSerializer(stringRedisSerializer);
        }
        return bean;
    }
}

再次运行测试代码，结果如下

127.0.0.1:6379> keys *user*
1) "user:PvwBNJFUKn"
2) "\xac\xed\x00\x05t\x00\x0fuser:mnaurYPzBt"
127.0.0.1:6379> get user:PvwBNJFUKn
"{\"name\":\"mfEESamnux\",\"id\":\"OFPcKTgwAm\"}"

写一个带有效期的数据

public class RedisTemplateTest extends DemoRedisTestBase {

    @SneakyThrows
    @Test
    void testSet() {
        String key = String.join(":", "user", RandomStringUtils.randomAlphabetic(10));
        Map<String, String> value = new HashMap<>();
        value.put("id", RandomStringUtils.randomAlphabetic(10));
        value.put("name", RandomStringUtils.randomAlphabetic(10));
        redisTemplate.opsForValue().set(key, objectMapper.writeValueAsString(value), 1L);
        String json = redisTemplate.opsForValue().get(key);
        System.out.println(json);
    }
}

指定了第3个参数1L，运行查看数据

发现没有，写入redis的数据最前面有一个不认识的字符\x00，其实是想当然的用错了方法，正确设置过期时间的姿势应该是这样

public class RedisTemplateTest extends DemoRedisTestBase {

    @SneakyThrows
    @Test
    void testSet() {
        String key = String.join(":", "user", RandomStringUtils.randomAlphabetic(10));
        Map<String, String> value = new HashMap<>();
        value.put("id", RandomStringUtils.randomAlphabetic(10));
        value.put("name", RandomStringUtils.randomAlphabetic(10));
        redisTemplate.opsForValue().set(key, objectMapper.writeValueAsString(value), 1L, TimeUnit.DAYS);
        String json = redisTemplate.opsForValue().get(key);
        System.out.println(json);
    }
}

应该使用这个4个参数的方法才是设置过期时间，再运行下

这下就正确了