If there is no parameter names "param" passed to the servlet (i.e. not part
of the query string for the servlet or not an input field on the form
posting to the servlet) then getParameter indeed returns null and you can
check it with
String param = getParameter("param");
if (param == null )
..... // Your investment in JAVA book is not wasted.
But if parameter param is passed to the servlet without a value,
getParameter will return an empty string "".
You can test this using
if(param != null && param.length() > 0); // To guard against
NullPointerException.
That's why you should always check for the parameter as
if (param != null && param.length() > 0 ) {
...// Do something useful with the parameter.
} else {
... /// Do something else.
}
I hope it helps.
Vivek
> -----Original Message-----
> From: Purav [mailto:[EMAIL PROTECTED]]
> Sent: Wednesday, August 16, 2000 5:17 AM
> To: [EMAIL PROTECTED]
> Subject: Re: getParameter method return null string
>
>
> Hi,
>
> So if I write
> if(Name.equals("null"))
> System.out.println("I have already invested in a Java book");
> else
> System.out.println("But Still I am Confused");
>
> will it work?
>
> Purav
>
>
> ----- Original Message -----
> From: "David Concannon" <[EMAIL PROTECTED]>
> To: <[EMAIL PROTECTED]>
> Sent: Wednesday, August 16, 2000 11:00 AM
> Subject: Re: getParameter method return null string
>
>
> > try
> >
> > if(Name.equals("null"))
> > System.out.println("I need to invest in a Java book");
> > else
> > System.out.println("Or look at the API");
> >
> >
> >
> > -----Original Message-----
> > From: Purav [mailto:[EMAIL PROTECTED]]
> > Sent: Wednesday, August 16, 2000 9:55 AM
> > To: [EMAIL PROTECTED]
> > Subject: [SERVLET-INTEREST] getParameter method return null string
> >
> >
> > Hi,
> >
> > The Request.getparameter() method return null string when
> it does not find
> > the parameter. it does not return null as a keyword
> >
> > so if i write
> > String Name=Request.getParameter("Name");
> > if(Name==null)
> > then something....
> >
> > It doesnt work
> >
> > I am little confused
> >
> > Can anybody help me out
> >
> >
> > Purav
> >
> >
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