Hi there Richard, thank you for your reply. I'll give the final keyword a go. With respect to:
If this is so, your application is not going to be thread-safe b/c the connection is static and can be used by different threads. If this is for a web application, you should use a connection pool and a datasource
I have been doing a java course and this is my first web app outwith the course material (thread safe connections have never been mentioned in the course). I don't know anything about connection pools/datasources where can I find a good tutorial or good newbie info on this? What problems will be be caused by using the non thread safe connection as it is at the moment? I'm thinking performance problems. Thank you again for your reply. Graeme :)
From: Richard Yee <[EMAIL PROTECTED]> Reply-To: A mailing list about Java Server Pages specification and reference <JSP-INTEREST@JAVA.SUN.COM> To: JSP-INTEREST@JAVA.SUN.COM Subject: Re: DB Connection prob Date: Mon, 19 Mar 2007 21:44:14 -0700 MIME-Version: 1.0 Received: from swjscmail2.java.sun.com ([192.18.99.108]) by bay0-mc3-f9.bay0.hotmail.com with Microsoft SMTPSVC(6.0.3790.2668); Mon, 19 Mar 2007 21:44:13 -0700 Received: from swjscmail1 (swjscmail1.Sun.COM [192.18.99.107])by swjscmail2.java.sun.com (Postfix) with ESMTPid 197BF219EE; Mon, 19 Mar 2007 22:40:58 -0600 (MDT) Received: from JAVA.SUN.COM by JAVA.SUN.COM (LISTSERV-TCP/IP release 1.8e) with spool id 14080077 for JSP-INTEREST@JAVA.SUN.COM; Mon, 19 Mar 2007 22:38:12 -0600 Received: from mail.cruzio.com (mail.cruzio.com [63.249.95.37]) by swjscmail1.java.sun.com (Postfix) with ESMTP id 645C6554F for <JSP-INTEREST@JAVA.SUN.COM>; Mon, 19 Mar 2007 22:38:09 -0600 (MDT) Received: from [192.168.0.103] (dsl-63-249-97-217.cruzio.com [63.249.97.217]) by mail.cruzio.com with ESMTP id l2K4i4um015259 for <JSP-INTEREST@JAVA.SUN.COM>; Mon, 19 Mar 2007 21:44:04 -0700 (PDT) X-Message-Info: txF49lGdW42b/sTindn8aktBOU0PkxWOZO3VQQBd2PraXRfcuczAxtZNUN2UNjMx X-Original-To: JSP-INTEREST@JAVA.SUN.COM Delivered-To: JSP-INTEREST@JAVA.SUN.COM User-Agent: Thunderbird 1.4 (Windows/20050908) References: <[EMAIL PROTECTED]> X-Spam-Status: No, score=0.0 required=1.0 tests=AWL autolearn=disabled version=3.1.7 X-Spam-Checker-Version: SpamAssassin 3.1.7 (2006-10-05) on mail.cruzio.com Precedence: list Return-Path: [EMAIL PROTECTED] X-OriginalArrivalTime: 20 Mar 2007 04:44:14.0634 (UTC) FILETIME=[694320A0:01C76AAA] Graeme, Since you mention that you are using a deployment descriptor, I am assuming this is for a web application. If this is so, your application is not going to be thread-safe b/c the connection is static and can be used by different threads. If this is for a web application, you should use a connection pool and a datasource. In your current problem, your variables should not be final. -Richard Graeme McLaren wrote:Hi all, I have a prob connecting to my Oracle DB. I have a class called "DBConnection" and have various setter methods which set values found in the deployment descriptor, for example: public static void setDriver (String val) { driver = val; System.out.println("driver 2= "+driver); // I get the value displayed here so all is good at this point } I then have a getConnection method within this class: public static Connection getConnection(){ try{ Class.forName( driver ); // load the JDBC "driver" class connection = DriverManager.getConnection( dbURL, username, password ); // get connection /* more code here */ } // end of getConnection When I try to call getConnection() I get a nullpointerexception at Class.forName( driver ); as "driver" is set to null, why is this when the setter method sets the value? All variables are declared set to null and are static so they should be able to be set by the setter method shouldn't they? Just thinking about it now I'm thinking that when the variables are initialised to "null" that is them set and cannot be changed because they are static (and final), would that be right? How should I fix this? Cheers Graeme :) =========================================================================== To unsubscribe: mailto [EMAIL PROTECTED] with body: "signoff JSP-INTEREST". For digest: mailto [EMAIL PROTECTED] with body: "set JSP-INTEREST DIGEST". Some relevant archives, FAQs and Forums on JSPs can be found at: http://java.sun.com/products/jsp http://archives.java.sun.com/jsp-interest.html http://forums.java.sun.com http://www.jspinsider.com=========================================================================== To unsubscribe: mailto [EMAIL PROTECTED] with body: "signoff JSP-INTEREST". For digest: mailto [EMAIL PROTECTED] with body: "set JSP-INTEREST DIGEST". Some relevant archives, FAQs and Forums on JSPs can be found at: http://java.sun.com/products/jsp http://archives.java.sun.com/jsp-interest.html http://forums.java.sun.com http://www.jspinsider.com
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