Which line is line 25 exactly?
Technically after the executeQuery(), rs may be null, so you should wrap
the next two lines in an if statement. ie:
rs = stmt.executeQuery("SELECT * FROM LE_TUTORIAL_DISCS");
if(rs) { rs.next(); System.out.println("Title = " + rs.getString("title") + " -- Artist =
" + rs.getString("artist")); rs.close(); // note to close the ResultSet
}
Peter
--
Peter Mount
Enterprise Support
Maidstone Borough Council
Any views stated are my own, and not those of Maidstone Borough Council.
-----Original Message-----
From: Nick Rathke [mailto:render@uswest.net]
Sent: Tuesday, April 18, 2000 5:17 AM
To: pgsql-interfaces@postgresql.org
Subject: [INTERFACES] Postgresql JDBC errors
I an using Postgresql-6.5.3 with jdbc6.5-1.2 and jdk1.2.2 on redhat
linux 6.2 . I
have tried to check the jdbc link using JDBCtest.java. Here is the info.
my classpath is
CLASSPATH=/lib/jdbc6.5-1.1.jar
JDBCtest.java
/* This file is part of the tutorial in Chapter 3 of "Getting Started
with Enhydra". It is not meant to be used in any other context.
Simple program to test JDBC connectivity. Assumes you have created
and populated a table called LE_TUTORIAL_DISCS in your database. Edit the connection string in the call to
DriverManager.getConnection()/
*/
import java.sql.*;
public class JDBCTest {public static void main( String[] args ) { Connection con = null; Statement stmt = null;
ResultSet rs = null;
// Load the driver, get a connection, create statement, run query, and
print. try { Class.forName("postgresql.Driver"); // Replace parameters below your database connection string,
username, and password con = DriverManager.getConnection("jdbc:postgresql:dbtest"
,"appserver", "appserver" ); stmt = con.createStatement(); rs = stmt.executeQuery("SELECT * FROM LE_TUTORIAL_DISCS");
rs.next(); System.out.println("Title = " + rs.getString("title") + " -- Artist =
" + rs.getString("artist")); } catch(ClassNotFoundException e) { System.err.println("Couldn't load the driver: " +
e.getMessage());} catch(SQLException e) { System.err.println("SQLException caught: " + e.getMessage()); }}
}
which gives me the errors:
Exception in thread "main" java.lang.NullPointerException: at
postgresql.jdbc2.ResultSet.getString(ResultSet.java:148) at
postgresql.jdbc2.ResultSet.getString(ResultSet.java:531) at
JDBCTest.main(JDBCTest.java:25)
I don't know enough about Java or databases to make any sense of this.
Any help would be great.
Nick Rathke