On Tue, 13 Mar 2001 [EMAIL PROTECTED] wrote:
> Yup, the jsp is in webapps/jdbctut/jdbctut.jsp
>
> This is where i get the err.
>
> if i use this stmt.
> ==> String value = getServletContext().getInitParameter("dbuser");
>
> or if i use this stmt
> ==>
> System.out.println(getServletConfig().getServletContext().getInitParameter
>
> or if i use these stmts
> ServletConfig sc = getServletConfig();
> ==> ServletContext sctx = sc.getServletContext();
> System.out.println(sctx.getInitParameter("dbuser"));
[ ... ]
Ahhh, it looks to me like a ServletConfig problem -- probably the well
known init ServletConfig problem. Do you override init(ServletConfig
config) in your servlet? If so, you need to make sure that the first
thing it does is call super.init(config). Or, as introduced in the
2.1 API, you can override a no-argument init() method.
Scratch that -- I see that your servlet code is still included below,
including the overriden init, and it looks like you do properly call
super.init(config). But from what you indicated above, it looks like
the ServletConfig or the ServletContext is null. I'm not sure why
else that would be.
How are you calling the servlet? Is that happening in the JSP? Maybe
it has something to do with that.
Not sure what else to suggest at this point.
> > -----Original Message-----
> > From: Milt Epstein [SMTP:[EMAIL PROTECTED]]
> > Sent: Tuesday, March 13, 2001 2:23 PM
> > To: [EMAIL PROTECTED]
> > Subject: RE: getServletContext null pointer exception
> >
> > On Tue, 13 Mar 2001 [EMAIL PROTECTED] wrote:
> >
> > > Thanks for your reply,
> > >
> > > This is the URL I am using
> > http://localhost:8080/jdbctut/jdbctut.jsp
> > >
> > > The class file is going into the webapps/jdbctut/Web-inf/classes of
> > the
> > > standard tom-cat installation.
> > [ ... ]
> >
> > Hmmm. I didn't realize you were using a JSP. But since this is
> > context-param's we're talking about, I don't think it should matter
> > (how you set up init-param's varies slightly for servlets and JSPs).
> >
> > Where is the JSP file located? webapps/jdbctut/jdbctut.jsp?
> >
> > Can you give more info about what the problem is, what error you are
> > getting? You say you are getting a null pointer exception. What does
> > the stack trace look like on that? Does it indicate where the
> > exception occurs (i.e. what line)? You might need to turn off the
> > compiler to see the line numbers.
> >
> >
> > > > -----Original Message-----
> > > > From: Milt Epstein [SMTP:[EMAIL PROTECTED]]
> > > > Sent: Saturday, March 10, 2001 9:26 AM
> > > > To: [EMAIL PROTECTED]
> > > > Subject: Re: getServletContext null pointer exception
> > > >
> > > > On Fri, 9 Mar 2001 [EMAIL PROTECTED] wrote:
> > > >
> > > > > Hi,
> > > > >
> > > > > I have been unable to get at the servletcontext param values. I
> > keep
> > > > > getting the null pointer exception.
> > > > > I have looked thru all the archives and quite a few sites trying all
> > the
> > > > > recommendations, but to no avail.
> > > > > Must be doing something really stupid, or I've missed a basic
> > concept
> > > > > somewhere.
> > > > > I am running tomcat 3.2.1
> > > > >
> > > > > Any hints would be gratefully appreciated.
> > > > > Thanks in advance.
> > > > > Chuck
> > > >
> > > > What URL are you using to access the servlet? Where (in the directory
> > > > structure) is your servlet class located?
> > > >
> > > >
> > > > > Here's my web.xml and the code trying to get at it.
> > > > >
> > > > > <web-app>
> > > > > <display-name>jdbctut</display-name>
> > > > > <description>This is version X.X of an application to
> > > > > perform</description>
> > > > > <context-param>
> > > > > <param-name>dbuser</param-name>
> > > > > <param-value>fabdev</param-value>
> > > > > <description>User name to logon to the Db.</description>
> > > > > </context-param>
> > > > > <servlet>
> > > > > <servlet-name>DataBaseSelect</servlet-name>
> > > > > <description> This servlet </description>
> > > > > <servlet-class>DataBaseSelect</servlet-class>
> > > > > <!-- Load this servlet at server startup time -->
> > > > > <load-on-startup>5</load-on-startup>
> > > > > </servlet>
> > > > > <servlet-mapping>
> > > > > <servlet-name>DataBaseSelect</servlet-name>
> > > > > <url-pattern>jdbctut</url-pattern>
> > > > > </servlet-mapping>
> > > > > <session-config>
> > > > > <session-timeout>30</session-timeout> <!-- 30 minutes -->
> > > > > </session-config>
> > > > > </web-app>
> > > > >
> > > > > import java.sql.*;
> > > > > import java.util.Vector;
> > > > > import javax.servlet.http.*;
> > > > > import javax.servlet.*;
> > > > > import java.io.*;
> > > > > public class DataBaseSelect extends HttpServlet {
> > > > >
> > > > > private Vector result;
> > > > > private String url =
> > > > >
> > "jdbc:informix-sqli://poldev:2005/fabdev:INFORMIXSERVER=poldev_713_tcp";
> > > > >
> > > > > public void init( ServletConfig config ) throws
> > > > > javax.servlet.ServletException{
> > > > > super.init( config ) ; // Essential!!
> > > > > }
> > > > >
> > > > > public DataBaseSelect() {
> > > > > result = new Vector();
> > > > > } // constructor DataBaseSelect
> > > > >
> > > > > public String connect() {
> > > > > try {
> > > > > Class.forName("com.informix.jdbc.IfxDriver").newInstance();
> > > > > return "Driver Loaded!";
> > > > > } catch (Exception E) {
> > > > > return "Unable to load driver.";
> > > > > }
> > > > > }
> > > > >
> > > > > public String select() {
> > > > > // String value =
> > getServletContext().getInitParameter("dbuser");
> > > > > //
> > > > >
> > > >
> > System.out.println(getServletConfig().getServletContext().getInitParameter
> > > > ("
> > > > > dbuser"));
> > > > > ServletConfig sc = getServletConfig();
> > > > > ServletContext sctx = sc.getServletContext();
> > > > > System.out.println(sctx.getInitParameter("dbuser"));
> > > > >
> > > > > try {
> > > > > Connection C = DriverManager.getConnection(url, "fabdev",
> > > > > "fabdev$");
> > > > > Statement Stmt = C.createStatement();
> > > > > ResultSet myResult = Stmt.executeQuery("SELECT lst_nm from
> > > > > person_profile ORDER BY lst_nm");
> > > > >
> > > > > while (myResult.next()) {
> > > > > result.addElement(myResult.getString(1));
> > > > > }
> > > > >
> > > > > // Clean up
> > > > > myResult.close();
> > > > > Stmt.close();
> > > > > C.close();
> > > > > return "Connection Success!";
> > > > > } catch (SQLException E) {
> > > > > return "SQLException: " + E.getMessage();
> > > > > }
> > > > > }
> > > > >
> > > > > /**
> > > > > * Accessor for result
> > > > > **/
> > > > > public Vector getResult() {
> > > > > return result;
> > > > > }
> > > > >
> > > > > /**
> > > > > * Mutator for result
> > > > > **/
> > > > > public void setResult(Vector avector) {
> > > > > result = avector;
> > > > > }
> > > > >
> > > > > } // class DataBaseSelect
> > > > >
Milt Epstein
Research Programmer
Software/Systems Development Group
Computing and Communications Services Office (CCSO)
University of Illinois at Urbana-Champaign (UIUC)
[EMAIL PROTECTED]
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