java.sql.SQLException: Protocol violation
From: message #91617 is a reply to message #90953
The problem of Protocol Voilation comes when you try to connect to Oracle and istead of getting response in recordset or execution there is a blockage appears. for example in Oracle if you have setup like changing userid after 90 days or 60 days. What happened is Oracle will start asking you a question that your password is expiring do you want to change it or not, It means Before connecting to Oracle JDBC is blocked by this question and Oracle needs an Answer yes or no before executing your Query. So, You have to either take the user id which never expires or see the setting in Oracle for such kind of things.
Changed/Renewed the user password solved the issue:
Oracle/PLSQL: Change a user’s password in Oracle
alter user user_name identified by new_password;
OR
Change Oracle Database User Password
SQL> password
Changing password for DAVID
Old password:
New password:
Retype new password: