getParameter question

[Bernard Sigmund Gustav]

i have 2 jsps, where
jsp1 has a form and submits a dynamic number of textboxes and combo boxes
and
jsp2 which receives those submitted

now, in jsp1, my textbox names are arrays, as in:

   
<form method="post" action="jsp2.jsp">
for(int a=0; a<size; a++)
{
   StringBuffer readingname = new StringBuffer();
   readingname.append("reading");
   readingname.append(a);
   readingname.toString();
   //now readingname is reading0, reading1,reading2, etc. depending on the number of textboxes
 
   <input type="text" name="<%=readingname%>" disabled class="textbox" size="6">
 
</form>
}

and how do i get those values in my jsp2?
i need to retrieve all the values inputted in the dynamic number of textboxes i have

thanks

[Bernard Sigmund Gustav]

i solved some of the problem:
i tried it with textboxes but it still doesn't work with combo boxes

this is what i did

   
<form method="post" action="jsp2.jsp">
for(int a=0; a<size; a++)
{   
    <input type="text" name="<%=readingname%>" disabled class="textbox" size="6"> 
</form>
}

and in jsp2

   
 
String[] readings = request.getParameterValues("reading");
for(int a=0; a<readings.length; a++)
{
out.println(readings[a]);
}

but if i do the same thing with combo boxes, it doesn't work

<select name="combo1">
<option value="1">1</option>
<option value="2">2</option>
</select>

and same as in jsp2

[Stefan Evans]

If your fields are named field0, field1, field2, field3..., then you have to retrieve the parameters under the names field1, field2, field3

ie

int currentIndex = 0;
String fieldName = "reading";
 
String paramValue = request.getParameter(fieldName + currentIndex++);
while(paramValue != null){
  // do something with this parameter value
  // eg add it to a list
  myValues.add(paramValue);
  // look for the next value
  paramValue = request.getParameter(fieldName + currentIndex++);
}

This code doesn't need to know how many items there are. It assumes when it doesn't find an item, that there are no more. That works for textboxes/select items, but won't work for checkboxes.


On request.getParameterValues(): this gets all the values for parameter.
eg reading=Headfirst Java&reading=Struts in Action&reading=Design Patterns
All of these have the same parameter name, but multiple values were submitted. However there is no guaruntee on the order of those parameters. In your case if the textbox and select box are linked, you can't be sure that you match them up correctly unless you number them yourself.

Also there is a useful package in the jakarta commons: BeanUtils.
If you name your fields field[0], field[1], field[2] then it will automagically retrieve them as array fields. (This is used in Struts)

Hope some of this helps,
evnafets

[Bernard Sigmund Gustav]

thanks very much.

you're a very good teacher.
i'll try your code.
i'm just not too sure about the struts thing though. i don't know how it works and how to use it

thanks again

[Bear Bibeault]

I woud not adopt Struts for something so trivial.