I'm not sure which one of these you're looking for, but:
getServletConfig().getInitParameter("myParameter") will get you the value of
an initialization parameter as specified in your web.xml configuration file
(by using <init-param>).
getServletContext().getAttribute("myAttribute") will retrieve an attribute
from what JSP calls the "application" context.
--
Martin Cooper
Tumbleweed Communications
----- Original Message -----
From: "Neal Cabage" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Saturday, December 30, 2000 4:03 PM
Subject: Re: Servlets -> access application obj
> This is driving me NUTS!!!!
>
> Could someone please explain to me how I must go about accessing the
> application object in order to get an application variable in my servlet.
> In a JSP I just write:
>
> application.getInitParameter("gUri")
>
> ....so far I have gotten the following frigured out (I think) ... but
still
> no dice!
>
> HELP!!!!!
>
> Thx.
>
> Neal
>
>
>
____________________________________________________________________________
> _________
>
>
>
>
> import java.io.*;
> import java.text.*;
> import javax.servlet.*;
> import javax.servlet.http.*;
> import javax.servlet.jsp.*;
>
> public class myServlet extends HttpServlet {
> public void doPost(HttpServletRequest request, HttpServletResponse
> response) throws IOException, ServletException {
>
> //Define initial objects
> PrintWriter out = response.getWriter();
> JspFactory factory = JspFactory.getDefaultFactory();
> PageContext pageContext =
> factory.getPageContext(this,request,response,null,
> false,JspWriter.DEFAULT_BUFFER,true);
>
> //Get JSP implicits, application and session.
> ServletContext application = pageContext.getServletContext();
> HttpSession session = pageContext.getSession();
>
> //Output - test by writing an application variable.
> response.setContentType("text/html");
> out.println(application.getInitParameter("gUri"));
>
> }
> }
>
>
>
>
>
> -----Original Message-----
> From: A mailing list about Java Server Pages specification and reference
> [mailto:[EMAIL PROTECTED]]On Behalf Of Craig R. McClanahan
> Sent: Saturday, December 30, 2000 9:15 PM
> To: [EMAIL PROTECTED]
> Subject: Re: [JSP-INTEREST] Servlets v. JSP
>
>
> "Duffey, Kevin" wrote:
>
> > Despite the fact that the spec says JSP must extend JSPServlet and all
> that,
> > I am wondering why its not allowed for an app server to do its own thing
> > with JSP pages.
>
> They are.
>
> The spec says that an app server can generate a class that extends
whatever
> base
> class it wants to, as long as the resulting servlet implements the
> javax.servlet.jsp.JspPage *interface* (not extends the JSPServlet *base
> class*).
> Most JSP page compilers provide a base class that is unique to that
> container,
> optimized to make your compiled classes as small as possible (shared code
> appears
> once in the superclass) and as fast as possible (optimized for the
internal
> organization of that container).
>
> > For example, I could map *.jsp to my own servlet, which
> > would then parse the JSP page, and convert it directly to a servlet..one
> > that does not extend JSPServlet or whatever it is. Why is it forced to
> > extend JSPServlet?
>
> As above, it is not forced. In fact, you as a page developer have the
right
> to
> tell the JSP compiler to use your own base class, instead of its own, if
you
> want
> to:
>
> <%@ page ... extends="com.mycompany.MyJspBaseClass" ... %>
>
> However, you are explicitly warned that this is likely to make performance
> *worse*,
> because the page compiler has to give up all the optimizations built in to
> the base
> class it knows about, and write extra code in the generated servlet to
make
> sure
> your page obeys all of the rules of the spec.
>
> > Seems to me to make it as fast as possible, it would be
> > better to just directly convert the JSP page into a single servlet that
> > extends nothing (if possible), and make it as lean and fast as possible.
I
> > don't know if there would be significant improvement in overall site
speed
> > because of this.
> >
>
> By this argument, we should never ever use subclasses, right? :-). I
guess
> we all
> need to go back to C programming -- this "object oriented" stuff wasn't
all
> it was
> cracked up to be :-) :-).
>
> Seriously, whether you use subclasses or not versus implementing the same
> code in
> every servlet has essentially no impact on performance (other than the
fact
> that it
> costs you more memory because of the code duplication). And, as we all
> know, if
> the code is only in one place (the superclass), it only needs to be
changed
> once
> when bugs are fixed or new features are added.
>
> The JSP spec gives container vendors quite a lot of latitude to
> differentiate
> themselves on the generated code quality (and thererfore performance) of
> their JSP
> implementations -- with you having a guarantee that your page will
function
> identically on any of them, as long as *you* obey all the spec rules.
This
> is the
> same kind of freedom you have to choose which JVM to run on. For example,
> try the
> same application on a JDK 1.1 JVM with the JIT turned off, versus a 1.3
JVM
> with
> HotSpot -- for many interesting classes of applications (including pretty
> much all
> web apps that are not I/O bound), the performance difference is dramatic.
> And that
> difference is totally due to changes in the underlying container -- not in
> your
> code.
>
> Craig McClanahan
>
>
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> DIGEST".
> Some relevant FAQs on JSP/Servlets can be found at:
>
> http://java.sun.com/products/jsp/faq.html
> http://www.esperanto.org.nz/jsp/jspfaq.html
> http://www.jguru.com/jguru/faq/faqpage.jsp?name=JSP
> http://www.jguru.com/jguru/faq/faqpage.jsp?name=Servlets
>
>
===========================================================================
> To unsubscribe: mailto [EMAIL PROTECTED] with body: "signoff
JSP-INTEREST".
> For digest: mailto [EMAIL PROTECTED] with body: "set JSP-INTEREST
DIGEST".
> Some relevant FAQs on JSP/Servlets can be found at:
>
> http://java.sun.com/products/jsp/faq.html
> http://www.esperanto.org.nz/jsp/jspfaq.html
> http://www.jguru.com/jguru/faq/faqpage.jsp?name=JSP
> http://www.jguru.com/jguru/faq/faqpage.jsp?name=Servlets
===========================================================================
To unsubscribe: mailto [EMAIL PROTECTED] with body: "signoff JSP-INTEREST".
For digest: mailto [EMAIL PROTECTED] with body: "set JSP-INTEREST DIGEST".
Some relevant FAQs on JSP/Servlets can be found at:
http://java.sun.com/products/jsp/faq.html
http://www.esperanto.org.nz/jsp/jspfaq.html
http://www.jguru.com/jguru/faq/faqpage.jsp?name=JSP
http://www.jguru.com/jguru/faq/faqpage.jsp?name=Servlets
