Pantaho MySQL 8 connection error Driver class 'org.gjt.mm.mysql.Driver' could not be found

While upgrading ETL scripts for Mysql 5.8 to MySQL8 upgrade, as soon as I have updated the data-integration/lib jar to mysql-connector-java-8.0.xx.jar, it has started blowing with following error.

Driver class 'org.gjt.mm.mysql.Driver' could not be found, make sure the 'MySQL' driver (jar file) is installed.

I did spent lot of time debugging and finally concluded, two things, I hope this may save others time in similar situation.

Reason: There is hardcoded jdbc driver name in org.pentaho.di.core.database.MySQLDatabaseMeta, and it always returns org.gjt.mm.mysql.Driver which is removed and new Driver with name com.mysql.jdbc.Driver or com.mysql.cj.jdbc.Driver should be used.

Solutions Any of below should be done to resolve.

1. Continue using the old jdbc jar.

2. Modify the org.pentaho.di.core.database.MySQLDatabaseMeta below method, compile and place it in classes directory.

   public String getDriverClass()  {
   if (getAccessType()==DatabaseMeta.TYPE_ACCESS_ODBC)
   {
       return "sun.jdbc.odbc.JdbcOdbcDriver";
   }
   else
   {
       return "com.mysql.cj.jdbc.Driver";
   }   }
   

3. Use the Generic database connection, then you can specify the driver class yourself. (Based on @Cyrus comment.)

Pentaho open bug reference.