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Posted to dev@tomcat.apache.org by Jim Rudnicki <jd...@pacbell.net> on 2000/05/27 09:58:21 UTC
Bug in getInitParameter()
I've just bashed up against odd behavior of getInitParameter(). It seems
that the canonical name specified in the web.xml must exactly match the
class name or it does not work. e.g. access
/myapp/servlet/abc.vault.PostFile
<servlet>
<servlet-name>pfa</servlet-name>
<servlet-class>abc.vault.PostFile</servlet-class>
does not result in getInitParameter() returning values. Oddly add a
mapping:
<servlet-mapping>
<servlet-name>pfa</servlet-name>
<url-pattern>/pfile</url-pattern>
and the same servlet does get the init parameters only when accessed thru
the mapped url: /myapp/pfile
If I change the canonical to match the fully qualified class name:
<servlet>
<servlet-name>abc.vault.PostFile</servlet-name>
<servlet-class>abc.vault.PostFile</servlet-class>
then /myapp/servlet/abc.vault.PostFile does get the init parameters, and the
mapped url also does.
Odd?
Jim
Re: Bug in getInitParameter()
Posted by Arion <ar...@talentinfo.com.hk>.
Hi!
And also, as you may have found, although the 2 servlet are of the same class, 2
instances would be created to serve the 2 different URL.
Arion
Hans Bergsten wrote:
> Jim Rudnicki wrote:
> >
> > I've just bashed up against odd behavior of getInitParameter(). It seems
> > that the canonical name specified in the web.xml must exactly match the
> > class name or it does not work. e.g. access
> > /myapp/servlet/abc.vault.PostFile
> >
> > <servlet>
> > <servlet-name>pfa</servlet-name>
> > <servlet-class>abc.vault.PostFile</servlet-class>
> >
> > does not result in getInitParameter() returning values. Oddly add a
> > mapping:
> >
> > <servlet-mapping>
> > <servlet-name>pfa</servlet-name>
> > <url-pattern>/pfile</url-pattern>
> >
> > and the same servlet does get the init parameters only when accessed thru
> > the mapped url: /myapp/pfile
> >
> > If I change the canonical to match the fully qualified class name:
> >
> > <servlet>
> > <servlet-name>abc.vault.PostFile</servlet-name>
> > <servlet-class>abc.vault.PostFile</servlet-class>
> >
> > then /myapp/servlet/abc.vault.PostFile does get the init parameters, and the
> > mapped url also does.
> >
> > Odd?
>
> It's not so odd ;-) The <servlet> element lets you configure a named
> instance of a servlet class and specify init parameters. In order for
> your servlet to see these parameters, you must invoke the named
> instance, i.e. with a URL like /myapp/servlet/pfa in your example.
> You can define multiple named instances of the same servlet class
> with different init parameters (and names, obviously).
>
> When you use a URL like /myapp/servlet/abc.vault.PostFile you ask the
> invoker to call an unnamed instance of your servlet. That's why you
> do not get the parameters. When you added the mapping, you mapped it
> to the named instance. Hence it worked.
>
> Hans
> --
> Hans Bergsten hans@gefionsoftware.com
> Gefion Software http://www.gefionsoftware.com
>
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Re: Bug in getInitParameter()
Posted by Hans Bergsten <ha...@gefionsoftware.com>.
Jim Rudnicki wrote:
>
> I've just bashed up against odd behavior of getInitParameter(). It seems
> that the canonical name specified in the web.xml must exactly match the
> class name or it does not work. e.g. access
> /myapp/servlet/abc.vault.PostFile
>
> <servlet>
> <servlet-name>pfa</servlet-name>
> <servlet-class>abc.vault.PostFile</servlet-class>
>
> does not result in getInitParameter() returning values. Oddly add a
> mapping:
>
> <servlet-mapping>
> <servlet-name>pfa</servlet-name>
> <url-pattern>/pfile</url-pattern>
>
> and the same servlet does get the init parameters only when accessed thru
> the mapped url: /myapp/pfile
>
> If I change the canonical to match the fully qualified class name:
>
> <servlet>
> <servlet-name>abc.vault.PostFile</servlet-name>
> <servlet-class>abc.vault.PostFile</servlet-class>
>
> then /myapp/servlet/abc.vault.PostFile does get the init parameters, and the
> mapped url also does.
>
> Odd?
It's not so odd ;-) The <servlet> element lets you configure a named
instance of a servlet class and specify init parameters. In order for
your servlet to see these parameters, you must invoke the named
instance, i.e. with a URL like /myapp/servlet/pfa in your example.
You can define multiple named instances of the same servlet class
with different init parameters (and names, obviously).
When you use a URL like /myapp/servlet/abc.vault.PostFile you ask the
invoker to call an unnamed instance of your servlet. That's why you
do not get the parameters. When you added the mapping, you mapped it
to the named instance. Hence it worked.
Hans
--
Hans Bergsten hans@gefionsoftware.com
Gefion Software http://www.gefionsoftware.com