JSP/Servlet: Is Form field Defined

[DiggidyMack69]

Hello folks I am working on a project using JSP's and Servlets. I have
a servlet that handles requests from several dynamic HTML forms. I
want to know if there is a way to check wether an HTML form field was
defined. In ColdFusion there is an isDefined() function. Right now I
am checking wether the request.getParameter("formfield") is null.
this has problems with fields left empty as nulls mean something in
this form. What is the best way to accomplish this??

DM

[Joe]

In article <c8*************************@posting.google.com> ,
Di***********@hotmail.com says...

I want to know if there is a way to check wether an HTML form field was
defined.

I think I'd do it this way:
public isDefined(HttpServletRequest req, String fieldNameToSearchFor) {
return req.getParameterMap().containsKey(fieldNameToSearc hFor);
}



--

Fuck George W. Bush!!!

[Joe]

In article <MP************************@sfo.news.speakeasy.net >,
sf***@spamcop.net says...

In article <c8*************************@posting.google.com> ,
Di***********@hotmail.com says...

I want to know if there is a way to check wether an HTML form field was
defined.

I think I'd do it this way:
public isDefined(HttpServletRequest req, String fieldNameToSearchFor) {
return req.getParameterMap().containsKey(fieldNameToSearc hFor);
}

oops, I meant:

public boolean isDefined(HttpServletRequest req, String fieldToSearchFor)
{
return req.getParameterMap().containsKey(fieldToSearchFor );
}

[Nathan Zumwalt]

It sounds like you already have the solution to this problem... check
for null. Fields that are left empty will return an empty string
("").

Alternatively, you could have a hidden input field that lists all the
fields on the screen. When it submits, parse this field first to get
your "valid" parameters.

-Nathan

Di***********@hotmail.com (DiggidyMack69) wrote in message news:<c8*************************@posting.google.c om>...

Hello folks I am working on a project using JSP's and Servlets. I have
a servlet that handles requests from several dynamic HTML forms. I
want to know if there is a way to check wether an HTML form field was
defined. In ColdFusion there is an isDefined() function. Right now I
am checking wether the request.getParameter("formfield") is null.
this has problems with fields left empty as nulls mean something in
this form. What is the best way to accomplish this??

DM

[DiggidyMack69]

Joe <sf***@spamcop.net> wrote in message news:<MP************************@sfo.news.speakeas y.net>...

In article <c8*************************@posting.google.com> ,
Di***********@hotmail.com says...

I want to know if there is a way to check wether an HTML form field was
defined.

I think I'd do it this way:
public isDefined(HttpServletRequest req, String fieldNameToSearchFor) {
return req.getParameterMap().containsKey(fieldNameToSearc hFor);
}

Joe, your a life saver. before I saw your post I popped all of the
results into an enumeration list and checked them manually. Your ways
is Definately much better. Thanks
public boolean isFormFieldDefined(HttpServletRequest request, String
x)
throws ServletException, IOException
{
String tests = "a";
String chkfield = x;
boolean def = false;
Enumeration enum = request.getParameterNames();
while (enum.hasMoreElements())
{
tests = (String)enum.nextElement();
if(tests.equals(chkfield))
{
def = true;
break;
}
}
return def;
}//end isFormFieldDefined.