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Posted to users@tomcat.apache.org by Pedro Santa <pe...@gmail.com> on 2008/01/03 14:01:49 UTC

Error while trying to parse a JSP from a bean

Hi all!

I'm getting an error while trying to parse a JSP from a bean. Here's the deal.

My site has 2 frames. On the first is the web page. The second one, I
want it to parse the contents of the first frame, in order to strip
some elements from the source code - but for testing purposes I now
only want to echo the entire source on the second frame.

To do this I've got a bean named Reader.java (package "reader") that
has a property 'url' to store the filename of the page I want to parse
and methods to set the url and to get the source of the url in a
String. Here's the code for the getSource method:

    public String getSource() {
        String result = "";
        try {
            URL urlobj = new URL("http://localhost:8080/myappfolder" + url);
            System.out.println("###### URL: " + urlobj.toString());
            BufferedReader in = new BufferedReader(new
InputStreamReader(urlobj.openStream()));

            String inputLine;

            while ((inputLine = in.readLine()) != null) {
                result += inputLine + "\n";
            }
            in.close();
        } catch (IOException ex) {
            System.out.println("### ERROR!");
            Logger.getLogger(Reader.class.getName()).log(Level.SEVERE,
null, ex);
        }
        return result;
    }


I use the Reader.java bean on the HTTP, session and when a page loads
updates the 'url' property of the bean.

The second frame is an application.jsp that reloads every 5 seconds,
and outputs the String from the Reader.java getSource method.

I pasted the all my jsp's on the
<tomcat_folder>\webapps\ROOT\myappfolder - as well as the context.xml
and web.xml files generated by Netbeans 6, the entire contents of
'web' folder. Pasted also all my classes on
<tomcat_folder>\webapps\ROOT\myappfolder\WEB-INF\classes and
<tomcat_folder>\webapps\ROOT\WEB-INF\classes.

When I try and fire up the page, the second frame displays nothing and
I get this error on Tomcat console: http://rafb.net/p/5auMCE76.html

I've tested the code with simple html files and it worked fine. I
tested the code with a jsp file without dynamic code (only HTML) it
worked fine either. And finally testes the code with the default jsp
for tomcat (http://localhost:8080/index.jsp) that has dynamic code in
it and it worked flawless as well.

I think I'm not doing something here, can anybody give me some advice
on how to put this thing to work?

I send also some useful information.

The application.jsp:

<%@page import="reader.*" %>
<html>
    <head>
        <META HTTP-EQUIV="Refresh" CONTENT="5; URL=application.jsp">
        <%
        HttpSession s = request.getSession();
        Reader reader = (Reader) s.getAttribute("reader");
        %>
        <title>JSP Page</title>
    </head>
    <body>
        <%
        out.print(reader.getSource());
        %>
    </body>
</html>

I'm using Windows XP Professional SP2, Jakarta Apache Tomcat 5.5.9
(downloaded from here
http://archive.apache.org/dist/jakarta/tomcat-5/v5.5.9/bin/jakarta-tomcat-5.5.9.exe)
and NetBeans IDE 6.0 Beta 2 (Build 200710212201).

All the other JSP features work fine.

:)

Thanks in advance.

Cheers.

Pedro Machado Santa

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Re: Error while trying to parse a JSP from a bean

Posted by David Smith <dn...@cornell.edu>.
myapp/index.jsp is throwing a NPE and returns a 500 error, causing the 
problem you see in application.jsp.  You should look at why 
myapp/index.jsp is throwing a NPE (NullPointerException).

--David

Pedro Santa wrote:

>Hi all!
>
>I'm getting an error while trying to parse a JSP from a bean. Here's the deal.
>
>My site has 2 frames. On the first is the web page. The second one, I
>want it to parse the contents of the first frame, in order to strip
>some elements from the source code - but for testing purposes I now
>only want to echo the entire source on the second frame.
>
>To do this I've got a bean named Reader.java (package "reader") that
>has a property 'url' to store the filename of the page I want to parse
>and methods to set the url and to get the source of the url in a
>String. Here's the code for the getSource method:
>
>    public String getSource() {
>        String result = "";
>        try {
>            URL urlobj = new URL("http://localhost:8080/myappfolder" + url);
>            System.out.println("###### URL: " + urlobj.toString());
>            BufferedReader in = new BufferedReader(new
>InputStreamReader(urlobj.openStream()));
>
>            String inputLine;
>
>            while ((inputLine = in.readLine()) != null) {
>                result += inputLine + "\n";
>            }
>            in.close();
>        } catch (IOException ex) {
>            System.out.println("### ERROR!");
>            Logger.getLogger(Reader.class.getName()).log(Level.SEVERE,
>null, ex);
>        }
>        return result;
>    }
>
>
>I use the Reader.java bean on the HTTP, session and when a page loads
>updates the 'url' property of the bean.
>
>The second frame is an application.jsp that reloads every 5 seconds,
>and outputs the String from the Reader.java getSource method.
>
>I pasted the all my jsp's on the
><tomcat_folder>\webapps\ROOT\myappfolder - as well as the context.xml
>and web.xml files generated by Netbeans 6, the entire contents of
>'web' folder. Pasted also all my classes on
><tomcat_folder>\webapps\ROOT\myappfolder\WEB-INF\classes and
><tomcat_folder>\webapps\ROOT\WEB-INF\classes.
>
>When I try and fire up the page, the second frame displays nothing and
>I get this error on Tomcat console: http://rafb.net/p/5auMCE76.html
>
>I've tested the code with simple html files and it worked fine. I
>tested the code with a jsp file without dynamic code (only HTML) it
>worked fine either. And finally testes the code with the default jsp
>for tomcat (http://localhost:8080/index.jsp) that has dynamic code in
>it and it worked flawless as well.
>
>I think I'm not doing something here, can anybody give me some advice
>on how to put this thing to work?
>
>I send also some useful information.
>
>The application.jsp:
>
><%@page import="reader.*" %>
><html>
>    <head>
>        <META HTTP-EQUIV="Refresh" CONTENT="5; URL=application.jsp">
>        <%
>        HttpSession s = request.getSession();
>        Reader reader = (Reader) s.getAttribute("reader");
>        %>
>        <title>JSP Page</title>
>    </head>
>    <body>
>        <%
>        out.print(reader.getSource());
>        %>
>    </body>
></html>
>
>I'm using Windows XP Professional SP2, Jakarta Apache Tomcat 5.5.9
>(downloaded from here
>http://archive.apache.org/dist/jakarta/tomcat-5/v5.5.9/bin/jakarta-tomcat-5.5.9.exe)
>and NetBeans IDE 6.0 Beta 2 (Build 200710212201).
>
>All the other JSP features work fine.
>
>:)
>
>Thanks in advance.
>
>Cheers.
>
>Pedro Machado Santa
>
>---------------------------------------------------------------------
>To start a new topic, e-mail: users@tomcat.apache.org
>To unsubscribe, e-mail: users-unsubscribe@tomcat.apache.org
>For additional commands, e-mail: users-help@tomcat.apache.org
>
>  
>


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