Re: Serialize its create method throws NullPointerException

From: "Dave Cramer" <Dave(at)micro-automation(dot)net>
To: "'Daems, Huub'" <Huub(dot)Daems(at)selektvracht(dot)nl>, <pgsql-jdbc(at)postgresql(dot)org>
Subject: Re: Serialize its create method throws NullPointerException
Date: 2001-11-20 14:05:58
Message-ID: 003501c171cc$7a65bf00$c201a8c0@inspiron
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Huub,

The following code works

package postgrestest;

/**
* Title: Postgres Tests
* Description:
* Copyright: Copyright (c) 2001
* Company: Ebox Inc
* @author Dave Cramer
* @version 1.0
*/

/*
* Java sample program
*/

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

public class lili implements Serializable
{

public String myString;
public int myNumber;

public lili() throws ClassNotFoundException, FileNotFoundException,
IOException, SQLException
{

myString="theString";
myNumber=4;
}
public boolean equals(lili l)
{
return (l.myString.equals(this.myString) && myNumber ==
this.myNumber);
}
private void testmethod(){};
public void testmethod2x(){};

public static void main(String args[])
{
org.postgresql.Connection conn=null;
try {
lili mylili = new lili();
lili test = null;
Class.forName("org.postgresql.Driver"); // load database
interface

// connect to the database
conn =
(org.postgresql.Connection)DriverManager.getConnection("jdbc:postgresql:
//alpha.ebox.com/davec", "davec", ""); // works
// test of serialisation
org.postgresql.util.Serialize.create(conn, mylili); // makes
problems
org.postgresql.util.Serialize s = new Serialize(conn,mylili);
int oid = s.store(mylili);
test = (lili)s.fetch(oid);
if (mylili.equals(test)){
System.out.println("Success");
}else{
System.out.println("Failure");
}
} catch(Exception exc){
System.err.println("Exception caught.\n" + exc);
exc.printStackTrace();
}finally{
try {
if (conn != null) conn.close();
} catch (Exception ex){
;
}
}
}

}

-----Original Message-----
From: pgsql-jdbc-owner(at)postgresql(dot)org
[mailto:pgsql-jdbc-owner(at)postgresql(dot)org] On Behalf Of Daems, Huub
Sent: Tuesday, November 20, 2001 7:39 AM
To: 'pgsql-jdbc(at)postgresql(dot)org'
Subject: [JDBC] 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

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