Re: jdbc works in java app, fails in servlet: "no suitable jdbc found"

HI - Thank you both Craig and Manohar.

There is no .WAR file in this project. So I am unable to follow related
advice.

There is a .CLASSPATH file stored with the project. It has the
following entry pertaining to the jdbc:
<classpathentry kind="con"
path="org.eclipse.datatools.connectivity.jdt.DRIVERLIBRARY/PostgreSQL
JDBC Driver"/>

There is also a .project file with various <buildSpec> and
<buildCommand> tags, and a .jsdtscope file with <classpath> and
<classpathentry> tags. But neither has any reference to the JDBC.

I'm thinking maybe I will refer back to the Eclipse Forum with this
research, as they will may know better if the registration is correct
and proper.

If I do get an answer, I will follow up here just in case anyone else
ends up pursuing the same matter.

With much appreciation,

Phil Freihofner

-----Original Message-----
From: Craig Ringer <craig(at)postnewspapers(dot)com(dot)au>
To: philfrei(at)aol(dot)com
Cc: pgsql-jdbc(at)postgresql(dot)org
Sent: Wed, Jun 2, 2010 7:19 pm
Subject: Re: jdbc works in java app, fails in servlet: "no suitable
jdbc found"

On 3/06/2010 8:28 AM, philfrei(at)aol(dot)com wrote: 
> Thank you for the reply! 
> 
>> You need to preload the PostgreSQL driver... 
> 
> Being new to this, I find myself second-guessing words as simple as 
> "preload". The servlet "NearbyTest" has a constructor and a single 
> method "doGet" which is invoked by an HTML page. As the first working 
> statement in the "doGet" method (at this point everything else is 
> commented out), I tried using the recommended statements. Both of
them 
> elicited the same error message: 
> 
> try { 
> // Class.forName("org.postgresql.Driver"); 
> this.getClass().getClassLoader().loadClass("org.postgresql.Driver"); 
> } catch (ClassNotFoundException e1) { 
> e1.printStackTrace(); 
> } 
> 
> java.lang.ClassNotFoundException: org.postgresql.Driver 
 
I'd say your classpath is misconfigured; the classloader cannot find
PostgreSQL. 
 
On web service containers sometimes the dependencies for the servelet
must all be embedded in a .war with the serverlet jar. Is that the case
here? 
 
> Is there another stage (prior to the servlet's 
> "doGet") at which the "preloading" should occur? 
 
Nope, just loading the class is sufficient. 
 
> The stack trace indicates code that is part of Apache. Is there
possibly 
> something that has to be configured in Apache that is missing? 
 
Well the trace refers to org.apache.catalina.loader.WebappClassLoader ,
which is a part of Apache Catalina. It has nothing to do with the
Apache web server except that they're both from the Apache project. 
 
Catalina is Tomcat's servlet container. 
 
That further suggests that you need to configure your classpath in your
web app environment, or have an issue with how your app and
dependencies are packaged. I've only done this stuff with Maven &
Netbeans targeting Glassfish, so I can't really offer much help with
the details of doing it right using Eclipse's build system and a Tomcat
target. 
 
-- 
Craig Ringer