import java.sql.*;

public class cs {

	public static void main(String args[]) throws Exception {
		Class.forName("org.postgresql.Driver");
		Connection conn = DriverManager.getConnection("jdbc:postgresql://localhost:5750/jurka","jurka","");

		Statement stmt = conn.createStatement();
		stmt.executeUpdate("CREATE OR REPLACE FUNCTION nullfunc(a int) RETURNS int AS 'BEGIN RETURN $1; END;' LANGUAGE plpgsql");
		stmt.executeUpdate("CREATE OR REPLACE FUNCTION nullfunc(a text) RETURNS text AS 'BEGIN RETURN $1; END;' LANGUAGE plpgsql");
		stmt.executeUpdate("CREATE OR REPLACE FUNCTION nullfunc(a timestamptz) RETURNS timestamptz AS 'BEGIN RETURN $1; END;' LANGUAGE plpgsql");
		stmt.close();

		CallableStatement cs = conn.prepareCall("{? = call nullfunc(?)}");
		cs.registerOutParameter(1, Types.INTEGER);
		cs.setNull(2, Types.INTEGER);
		cs.execute();
		int result = cs.getInt(1);
		System.err.println(result);
		cs.close();

		conn.close();
	}
}