在使用SpringBoot Redis里的scan方法扫描匹配的keys时出现了诡异的乱码前缀，类似如下截图：

字符串如下：

��t�online-token-eyJhbGciOiJIUzUxMiJ9.eyJqdGkiOiIwOWM1MDVkM2ZlMjE0OGVmYTk5MmQwNjhlOGVkYzNmMCIsInVzZXIiOiJhZG1pbiIsInN1YiI6ImFkbWluIn0.fB8T1s1tK6Z4SM9nGu1Dot9EXmdOoxcDaBIhcMur00RQy5PZk0fADRSf0gqFWGhjhrfEXFGaE1kpuwQ6qQi_kw

scan的实现源码如下：

public List<String> matchScan(String pattern) {
        List<String> keys = redisTemplate.execute((RedisCallback<List<String>>) connection -> {
            List<String> keysTmp = new ArrayList<>();
            Cursor<byte[]> cursor = connection.scan(ScanOptions.scanOptions().match(pattern).count(10000).build());

            while (cursor.hasNext()) {
                keysTmp.add(new String(cursor.next()));
            }
            return keysTmp;
        });

        return keys;
    }

原因分析

刚开始的时候找了很久没有找到原因，最后在stackoverflow上找到了提示：
https://stackoverflow.com/questions/55967558/spring-data-redis-hash-keys-with-weird-prefixes-and-hscan-not-returning-resul

原来是序列化问题导致，默认使用了JDK的序列化方法。

解决方案

采用Redis自带的序列化方法。初始化redisTemplate时，进行设置，代码如下：

 public RedisUtils(RedisTemplate<Object, Object> redisTemplate) {
        this.redisTemplate = redisTemplate;
        this.redisTemplate.setHashKeySerializer(new StringRedisSerializer());
        this.redisTemplate.setKeySerializer(new StringRedisSerializer());
        this.redisTemplate.setStringSerializer(new StringRedisSerializer());
    }

重新构建运行后，正常了。