RE: problem with serialization

Chris,


This will work, the fields have to be public to for introspection

/*
* 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 candreol
Sent: July 26, 2001 4:02 AM
To: dave(at)fastcrypt(dot)com; pgsql-jdbc(at)postgresql(dot)org
Subject: Re: [JDBC] problem with serialization

Hi Dave,
thank you!
It would be nice if you fix it. I had some problems with compiling , I
would be very happy if could send me a new jar.

chris

Dave Cramer wrote:

That is definately a bug. Chris; do you have a way to compile the
source? I can fix it and provide you with a driver to test if you need
?Dave

-----Original Message-----
From: Nandu [mailto:cr_nandu(at)yahoo(dot)com]
Sent: July 26, 2001 4:32 AM
To: candreol; Dave(at)micro-automation(dot)net; pgsql-jdbc(at)postgresql(dot)org
Subject: RE: [JDBC] problem with serialization

I think i know the problem, as the Serialise class of postgres there is
a line of code which will never work.It is like:if(!rs.next()) {
// they print something here like System.out.println(" Driver
Manager: " + rs.getString()) //which will always be null because
getString() will return null when rs.next() == false}I feel that it is a
bug with the Serialise implementation in postgresComment that line out
and u won't get Null pointer problem.Cheers,Nandu.

-----Original Message: pgsql-jdbc-owner(at)postgresql(dot)org
[mailto:pgsql-jdbc-owner(at)postgresql(dot)org]On Behalf Of candreol
Sent: 26 July 2001 07:35
To: Dave(at)micro-automation(dot)net; pgsql-jdbc(at)postgresql(dot)org
Subject: Re: [JDBC] problem with serialization

Hi Dave,

The code is very small. It is just a test :

/*
* Java sample program
*/

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

public class lili implements Serializable
{

String myString;
int myNumber;

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

myString="theString";
myNumber=4;
}

private void testmethod(){};
public void testmethod2x(){};

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

// connect to the database
org.postgresql.Connection conn =
(org.postgresql.Connection)DriverManager.getConnection("jdbc:postgresql:
//localhost:5432/onlinechess", "postgres", "mypassword"); // works

// test of serialisation
org.postgresql.util.Serialize.create(conn, mylili); // makes
problems

} catch(Exception exc)
{
System.err.println("Exception caught.\n" + exc);
exc.printStackTrace();
}
}
}

Dave Cramer wrote:

Chris,

Can you send us your code. Or a snippet?

Dave

Hi! I am new here.

I did a small test to try object serialization with the
org.postgresql.util.Serialize class.

I get the following exception when I try to use the at
org.postgresql.util.Serialize.create Method. :

java.lang.NullPointerException
at org.postgresql.jdbc2.ResultSet.getString(ResultSet.java:148)
at org.postgresql.util.Serialize.create(Serialize.java:241)
at org.postgresql.util.Serialize.create(Serialize.java:220)

I looked at create in Serialization.java and saw that
the exception occurs at getString although I have no table corresponding

to the class I want to serialize.
if(!rs.next()){
// String lolo=rs.getString(1);}
}

Although the resultset is empty (because the table is absent) , why
getString has been run ?

Can you help me ?

Chris

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