Can you capture the full stack trace for the NullPointerException? The behavior for converting to String should work if the JDBC driver itself implements this method correctly for the object they return for the column (see here). Unfortunately, as there are a myriad of JDBC drivers from different vendors, it's entirely possible that for the specific driver you are using, that is not the case. Feel free to open a Jira with as much detail as you can provide (table DDL, exact driver jar and version, etc.) and we can investigate.