With the statement
VALUES CAST(? AS VARCHAR(29))
PreparedStatement.setTimestamp(int,Timestamp) and PreparedStatement.setTimestamp(int,Timestamp,Calendar) don't agree on what to do with trailing zeros in the nanosecond component. The method that doesn't take a Calendar argument, removes trailing zeros. The method that takes a Calendar object appends zeros so that the nanosecond component always has nine digits. (Both methods have a special case when nanoseconds is zero, and they agree on adding just a single zero after the decimal point in that case.)
The format used by PreparedStatement.setTimestamp(int,Timestamp) matches what java.sql.Timestamp.toString() returns (in fact, it uses Timestamp.toString() internally to produce the string representation), and I think it would be reasonable to use that format for both the methods.