Servlet Request Parameter return null - java

My code is as follows:
<c:forEach items="${cashInList}" var="list" varStatus="stat">
<tr>
<td>${list.dateandtime}
</td>
<td><fmt:formatNumber type="number" pattern="###,###,###,##0.00" value="${list.cashAmount}" />
</td>
<td>
<input id="checkBoxID" type="checkbox" name="checkBoxValues" value="${list.checkBoxValue}" />
${list.checkBoxValue}
</td>
</tr>
</c:forEach>
in the controller bean
String[] checkedValues = req.getParameterValues("checkBoxValues");
However I got a null value.

When an HTML page is submitted, no parameters are sent on the HTTP request for inputs of type "checkbox" if they are not checked.
Try a simple sample with a static HTMl page containing a simple form with two checkboxes, one checked and the other one not checked. In the development tools of your browser you should see that only a parameter for one input is added on the request.
There is also a problem in your code, you have several inputs with the same ID. You should have a different ID for each checkbox.

Related

How to catch a table in POST and use it as an array

so basically to lay this out I have
AffidavitController - Controller
Affidavit.jsp - GET view page
summary.jsp - POST view page
so basically I have a form that a user fills out and then they hit the submit button and it posts it.
This method is then called in the controller
#RequestMapping(value = "/affidavit", method = RequestMethod.POST)
public String post(AffidavitDetailDto affidavitDetail, HttpServletRequest request, HttpServletResponse response, Model model) {
now within this method I catch the information that was passed over in the response object.
an example of this is I have a name field on the GET view page and the name of this field is 'custName'
so I catch it like so
String contactName = request.getParameter("custName");
model.addAttribute("contactName", contactName);
and then I can display it on my POST view page
<p>Name: ${contactName}</p>
but now I am trying to figure out how I can do the same with a table and treat it like an array
the following is how it is added on the GET view page
<table id="certEmail" name="certEmail">
<tr>
<td>${user.email}</td>
</tr>
</table>
the following is what I have attempted
String[] certEmail = request.getParameterValues("certEmail");
model.addAttribute("certEmail", certEmail);
and this is what I have on the view page to display it
<div id="Emails">
<c:forEach items="${certEmail}" var="email">
<p>${email}</p>
</c:forEach>
</div>
this does not currently work. I know I am probably just doing it wrong so can someone please at least point me in right direction. I just haven't figured out a good google query yet to get an answer.
Table is not a form element (https://www.w3schools.com/html/html_form_elements.asp). Only form element values on form are submitted to server. So instead of
<table id="certEmail" name="certEmail">
<tr>
<td>${user.email}</td>
</tr>
</table>
You should have something like
<table id="certEmail">
<tr>
<td>
<input type="text" name="certEmail" value="${user.email}" />
</td>
</tr>
</table>
if you want your data to be editable, or
<table id="certEmail">
<tr>
<td>
${user.email}
<input type="hidden" name="certEmail" value="${user.email}" />
</td>
</tr>
</table>
if you want it to be hidden and just resent to the server.
While I should denote that second variant generally should be avoided. I would recommend you to pass the user id and use it in back-end to load user and read his email.
Please learn how to use HTML forms: https://developer.mozilla.org/en-US/docs/Learn/HTML/Forms/Your_first_HTML_form

How to edit fields of a table?

I have a table to show a long list of items, I am wondering how I can edit the fields and submit the form to update them?
<form name="edit" method="POST" action="edit">
<table border="4">
<tbody>
<c:forEach items="${basket.items}" var="item">
<tr>
<td>
<input name="item.id" value="${item.id}"/>
</td>
<td>
<input label="Price" value="${item.product.price}"/>
<br/>
</td>
</tr>
</c:forEach>
</tbody>
</table>
this is a new one
<input id="edit" type="submit" name="edit" value="Edit"/>
</form>
You are using Struts2, with JSTL and EL instead of Struts Tags and OGNL... is there a particular reason that forces you to drop most of the framework mechanics ?
That said, your inputs aren't valid (no type specified) and the "this is a new one" sentence in the HTML seems to indicate the willing to insert a new row, instead of editing the existing entres. Your description and your code seem to ask two different things... to insert a new one, just make a call to another method of the action (or another action) called "add" instead of "edit", sending one single element and adding it to the collection. No need to use AJAX here...
If instead, the question is really:
how I can edit the fields and submit the form to update them ?
this is the way:
<s:form method="POST" action="edit">
<table border="4">
<tbody>
<s:iterator value="basket.items" var="item" status="ctr">
<tr>
<td>
<s:textfield name="item[%{#ctr.index}].id" />
</td>
<td>
<s:textfield name="item[%{#ctr.index}].product.price" />
</td>
</tr>
</s:iterator>
</tbody>
</table>
<s:submit value="Edit"/>
</form>
I would suggest you make an AJAX call using jquery to update the new one. And then in the success handler you can append the new line to the existing table. Before doing that you need to give your table proper ids so that its easier to use JQUERY.
var newLine = document.createElement("tr");
var cellName = document.createElement("td");
$(cellName).text("itemId");
$(newLine).append(cellName);
// similarly create other td's
$("#modelTable").append(newLine);// replace modelTable by the id of your table

Validate programatically generated form fields on client side and server side

I have a struts2 form that is programatically generated upon request. The element names for all the fields are the same namely idA and paramValue because I am passing the form values as array and looping through it for database inserts. Inserts are now OK, but I am still finding out how to validate the form.
Here's the form:
<s:iterator value="sysParamList" var="sysParam">
<tr>
<td>
<strong><s:property value="paramName" /></strong>
<input type="hidden" name="idA" value="<s:property value="id" />" />
</td>
<td>
<input type="text" name="paramValue" />
</td>
</tr>
</s:iterator>
The properties in my action are declared like
private String[] idA;
private String[] paramValue;
And I pass these in my DAO as-is. The DAO does the looping through the array for database insert.
I can validate forms using jquery.validate IF the form is hard coded in the JSP.

Sending form parameters from JSP to Struts action class

I am implementing a search functionality in a website I am building, which involves searching by the md5 hash of the name of the file submitted and searching by the notes associated with each submitted file. So, I should detect as to which button is pressed "Search by MD5" or "Search by Notes". This is the code I have:
JSP code for the form:
<form id="search" name="search" action = "search.do"
method="POST" enctype="multipart/form-data">
<table align = "center">
<tr>
<th colspan="4" bgcolor="#004276"><font color="white">
Search for Sample
</th>
</tr>
<tr>
<td><input name="md5" type="text" value="${form.md5}"/></td>
<td><input name="md5search" type="submit" value="Search by MD5"/>
</tr>
<tr>
<td><input name="notes" type="text" value="${form.notes}"/></td>
<td><input name="notessearch" type="submit" value="Search by Notes"/>
</tr>
</table>
</form>
search.do is mapped to SearchResultsAction.java. Code in Java action class (SearchResultsAction) which handles the request is:
if(request.getParameter("md5search").toString().equals("Search by MD5")){
searchSubmissionsList = submissionsDAO.searchSubmissionsByMD5(form.getMD5());
}
if(request.getParameter("notessearch").toString().equals("Search by Notes")){
searchSubmissionsList = submissionsDAO.searchSubmissionByNotes(form.getNotes());
}
But the problem I am facing here is that, request.getParameter("md5search") and request.getParameter("notessearch") return null for some reason. I have been working on this for a while and have not been able to figure it out. The weird thing is that it once worked for me sometime back when I was working on another project. Am I missing something here?
It's null because you used multipart/form-data form encoding instead of (default) application/x-www-form-urlencoded. Basically, you have to (let Struts) extract the text fields from the multipart form data body the same way as you (or Struts) extracted the uploaded file. Or, as there is actually no <input type="file"> field in your form at all, just remove the enctype attribute altogether.
See also
Does form with enctype="multipart/form-data" cause problems accessing a hidden field

How to get custom value from text field in JSP?

I'm working in a very simple and small web application, it is a jsp that handles a shopping cart.
What I do at this point is to iterate through all the products that are stored in the car and add them one by one to the jsp with each iteration.
This is the code that adds a row to the jsp in each iteration:
<tr>
<td>
<input type=text name=Quantity value=<%=quantity%>>
</td>
<td>
<input type=text name=id value=<%=id%>>
</td>
<td>
<input type=submit value="Delete" onclick=<%CustomSubmit(request, id); %>>
</td>
</tr>
As you can see I add to the end of each row a submit type control with a custom method for handling Click events, the use of this control is to remove from the car the respective product.
The problem that I have is that when I click in the delete button of a product, the id that is passed to the CustomSubmit(...) method is not the id of the product that I'm trying to remove but the id of the last product added to the jsp.
So, my question is how can I get the correct id from the item that I'm trying to remove?
The way i use to do it is as follows:
Replace
<input type=submit with a button
<input type="button" value="Delete" onclick="deleteIt('yourid');" />
add the deleteIt javascript function, in the function you fill a hidden input field with the id.
Then submit the page and the correct id gets passed to your page
Little sidenote its always prudent to escape all your Strings
dont use <input type=submit but use <input type="submit"
maybe like
<td>
<input type="text" name="id" value="<%=id%>">
</td>
<td>
<input type="button" value="Delete" onclick="deleteItem('<%=id%>')">
</td>
I assume your cart is a list of objects, each having the attributes id and quantity. So I would expect you code to look something like this (noting Peter's answer about using a 'button'):
<input type="button" value="Delete" onclick="CustomSubmit('<%=cartItem.id%>');"/>
I'm not entirely sure what you are trying to do with the 'request' parameter in your original code but if this is the HTTP request all you will get when you try to write it to the JSP is the result of the request.toString method.

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