Serialize its create method throws NullPointerException

Hi,

does some one has a clou how to use org.postgresql.util.Serialize to create
a table from my class....


package kermitserver.PL;

import java.io.*;
import java.util.*;
import java.sql.*;
import org.postgresql.util.Serialize;


public class Jk implements Serializable {

    public int oid;

    public Jk() {
    }

    public static void main(String[] args) {
        Jk jk1 = new Jk();
        jk1.oid = 0;   // just in case, only for this test

    try {
        Class.forName("org.postgresql.Driver");
        Connection db =
DriverManager.getConnection("jdbc:postgresql:kermitserver", "huub",
"secret");


org.postgresql.util.Serialize.create((org.postgresql.Connection)db, jk1);

        db.close();

    } catch (ClassNotFoundException cnfe) {
        cnfe.printStackTrace();
    } catch (SQLException sq) {
        sq.printStackTrace();
    } catch (NullPointerException npe) {
        npe.printStatckTrace();
    }
}


Try to run it and it gave an NullPointerException:

    java.lang.NullPointerException
    at org.postgresql.jdbc2.ResultSet.getString(ResultSet.java:171))
    at org.postgresql.util.Serialize.create(Serialize.java:241)
    at org.postgresql.util.Serialize.create(Serialize.java:220)
    at kermitserver.PL.jk.main(jk.java:37)

I am wondering what the ResultSet is doing.
I am using jdk1.3.1_01 from Sun, jdbc7.1-1.2.jar on postgresql 7.1.3 on SuSe
7.3

Would be nice if someone has an idea....

greeting Huub