handling html parameters in a jsp page

[federico tonioni]

Hi to all!
I have the following code in a jsp page:

<% for (int i = 0; i < collectionArray.length; i++) {
%>
<tr>
<td width="18%"><a href="documentview.jsp?id=<%= collectionArray[i]%>"><%= collectionArray[i] %></a></td>
<td width="17%"><input type="checkbox" name="checkbox" value="<%= collectionArray[i] %>" >
</td>
</tr>
<%
}
}
catch (XMLDBException e) {
response.getWriter().println("adminstart.jsp Exception occured " + e.errorCode);
}
finally {
if (col != null) {
col.close();
}
}%>
</table>

<p>
<input type="submit" name="choice" value="Delete Checked Collection" >

</form>
<p>
<form name="insertionForm" action="CollectionFormProcess" method=post >
<input type="submit" name="choice" value="Insert a collection name" >
<input type="text" name="collectionName" >
</form>
</p>
iwould like to know if it is possible to get the value of the submit html variable...
i would like to know if it possible to write the following:
<% if choice.value.equals(null) choice.value= "Insert a collection name" %>
my problem is that the servlet rises a NullPointerException when an user write some text in the collectionName field and press Enter because the servlet makes an if-clause on the "choice" value
if (request.getParameter("choice").equals("Insert a collection name")) {
//some code
}
else
// other code

any help would be highly appreciated
thank you in advance
federico

[Dominic Paquette]

Hi
From what I see in the code you posted, when you call
request.getParameter("choice")
it should return the string "Insert a collection name", I tried it and it works.
are you sure the exception is comming from that statement?
Dominic

[Bosun Bello]

You are calling equals on null. Try this...
<% if choice.value == null) choice.value= "Insert a collection name" %>

[Dominic Paquette]

I don't think that calling equals with a null parameter throws an exception, I think it simply returns false
Dominic

[Asher Tarnopolski]

dominic is right. it just returns false.
to the main questio: can you please post your code as it is in your java/jsp file?