Using Azure JDBC authentication plugin with MysqlConnectionPoolDataSource throw exception.

[guo zhihao]

Hi all:
I am using mysql-connector-java(mysql-connector-j) and extended AuthenticationPlugin in com.azure:azure-identity-providers-jdbc-mysql:1.0.0-beta.1 to connect Azure hosted MySQL server.
In this way, instead of authenticating with username/password, I can use the AuthenticationPlugin to perform authentication with username/accessToken.

But the accessToken is very long(about 1767 characters), and when I was using MysqlConnectionPoolDataSource, I encounted an issue: https://github.com/Azure/azure-sdk-for-java/issues/31599.


Question:
I have a workaround to fix this as the doc says, but still I have a question: why there is a 256 limitation here:https://github.com/mysql/mysql-connector-j/blob/27603148f10a5f47467bec7ad26a5ca28da63c72/src/main/protocol-impl/java/com/mysql/cj/protocol/a/NativeAuthenticationProvider.java#L679-L685.


I would appreciate it if any one could help me with this question.

Thanks.