mysql-connector-java-8.0.28 mysql malicious server jdbc deserialization failure reasons

Refer to https://xz.aliyun.com/t/8159
https://daybr4ak.github.io/2020/07/23/MySQL-JDBC%E5%8F%8D%E5%BA%8F%E5%88% 97%E5%8C%96%E5%AD%A6%E4%B9%A0/ Introduces the principle of
deserialization

But in 8.0.28, he directly uses getString instead of getObject, so it cannot be deserialized