Your code isn't safe. If "go" isn't specified in the query string, you
will be calling equals() on a null object. That's why you get a
NullPointerException.
You can fix this by using the code below:
String go = request.getParameter("go");
if ("tips".equals(go)) {
showTips(response);
}
This code won't throw a NullPointerException if go is null. You could also
do
something like this:
if (go != null && go.equals("tips")) {
[ Matthias Carlsson ]
[ Programmer (Java, XML/XSL, CGI/Perl, HTML/JS) ] [ Web Designer ]
[ E-Mail : [EMAIL PROTECTED] ] [ ICQ: 1430647 ]
> -----Ursprungligt meddelande-----
> Fran: A mailing list for discussion about Sun Microsystem's Java Servlet
> API Technology. [mailto:[EMAIL PROTECTED]]For roy woods
> Skickat: den 8 april 2001 11:38
> Till: [EMAIL PROTECTED]
> Amne: Re: Query String Value is returning null. why?
>
>
> I am simply using this:
>
> String go = req.getParameter("go");
> if(go.equals("tips")){
> showTips(res);
> }
>
> and I get the java.lang.NullPointerException on the
> browser. Could you show me how you do it in simple
> code?
>
> roy
>
>
> --- Robert Nicholson <[EMAIL PROTECTED]> wrote:
> > What happens when you iterate over the requests
> > parameter list. What's
> > there? What to does QueryHash's keyEnumerator show?
> >
> > > -----Original Message-----
> > > From: A mailing list for discussion about Sun
> > Microsystem's Java Servlet
> > > API Technology.
> > [mailto:[EMAIL PROTECTED]]On Behalf Of
> > roy
> > > woods
> > > Sent: Saturday, April 07, 2001 12:34 PM
> > > To: [EMAIL PROTECTED]
> > > Subject: Query String Value is returning null.
> > why?
> > >
> > >
> > > Hi all
> > >
> > > In my Servlet I have a link like this:
> > > http://localhost/servlet/Library?go=tips But the
> > Query
> > > string value is ignored. I mean, go has no value.
> > > and the parameter go returns null. On my browser I
> > > therefore get
> > >
> > > Error: 500
> > >
> > > Location: /servlet/Library
> > >
> > > Internal Servlet Error:
> > >
> > > java.lang.NullPointerException:
> > >
> > > How can I get the query string values?
> > >
> > > Thanks in advance
> > >
> > > roy
> > >
>
>
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