Null values, post forms....?!

[Zein Nunna]

Ok guys im using Jakarta, commons, upload to upload a file on to my webserver.

Now that all works fine, however I can access varibles that are enclosed in
<%
String x = ....
%>

request.getParameter.... doesnt work.

In my servlets, how do i get around this (i'd prefer to avoid beans), could you give me example code etc.,

Thanks in advance
Zein

[Ben Souther]

There is an "isFormField" property to the FileItem object.
Just test for true while looping through them.

DiskFileUpload upload = new DiskFileUpload();
List           files  = upload.parseRequest(request);
Iterator       it     = files.iterator(); 
 
while(it.hasNext()){
    FileItem item = (FileItem)it.next();                                                                                                           
    if(item.isFormField()){ 
        System.out.println("FIELD: "  
                            + item.getFieldName() 
                            + " : " 
                            + item.getString());
    }                                                                                                                               
}

[ April 18, 2005: Message edited by: Ben Souther ]

[Zein Nunna]

Yes, I have tried that, that gets the form fields, thats fine.

But there are other varibles in the that are in <%... %> that I cant seem to access, they just come up as null. Normally I would access them via request.getParameter("...") and that would work.

Any ideas?

[Ben Souther]

Can you post an example?

[Zein Nunna]

Ok the varible i want access is paper_id

  
<%
String paper_id = request.getParameter("paper_id");
String version = request.getParameter("version");
%>

In my servlet I have the following code: [I put all the values from the form into a HashMap, I can access them fine, its just values that are not in the form?]

 while (iter.hasNext()) {
item = (FileItem) iter.next();
if (item.isFormField()) {
 
field = item.getFieldName();
value = item.getString();
 
//this is a hash map 
vars.put(field, value);
 
}
//item = (FileItem) iter.next();
else {
File uploadedFile =
new FileUtil().create(filePath, fileName);
item.write(uploadedFile);
updateDB();
 

Any ideas, cues etc..?

Thanks Zein

[Ben Souther]

You'll need to include the value of that variable in the HTML form.

  
<input type="text" name="paper_id" value="<%=paper_id%>" />.

Regardless of the server side technology you are using, it's important to understand how HTTP and HTTP forms work. Two things that I recommend for people trying to get a handle on these concepts are:

1.) Get in the habit of always viewing the HTML source from your browser.
This is the output from your server side code.

2.) Install either a packet sniffer like tcpflow or install the Live HTTP Headers plugin to Firefox.
Either product will allow you to view what gets sent from the browser to the server when you submit a web page form.

[Zein Nunna]

Cheers ben works like a charm [with some light modification]

The code above makes the fields visible on the form, just need to hide them as you dont want the user to seem them.

<input type="hidden" name="paper_id" value="<%=paper_id%>" />
  

Thanks for the advice, really appreciate it.

Zein