DefaultSerializer requires a Serializable payload but received an object of type...

The entity class inherits Serializable

 　　　　Student stu= null;
       ...
        redisTemplate.opsForValue().set(key+ token, stu);
        redisTemplate.expire(key+ token,expiration, TimeUnit.MILLISECONDS);

Here, if the Student class does not inherit Serializable, it will report the above error;