Spring MVC - Submit an Object from JSP - java

I have a JSP that presents a list of customers (ArrayList searchResults). I want to be able to pick one of those, and submit it to a Spring MVC controller. However, it appears that I cannot pass the selected object, only a property of it, such as customerId. I really need to pass the entire object.
Is there a standard way to do this in Spring 3.x?
<c:forEach items="${searchResults}" var="searchResult">
<tr>
<td><c:out value="${searchResult.customerId}" /></td>
<td><c:out value="${searchResult.firstName}" /></td>
<td><c:out value="${searchResult.lastName}" /></td>
<td>
<form method="POST" ACTION="./customercare">
<input type="SUBMIT" value="Select This Customer"/>
<input type="hidden" name ="searchResult" value="${searchResult}"/>
</form>
</td>
</tr>
</c:forEach>

You can use Spring's form taglib instead of plain <form> to post back to a Spring MVC Controller and then it will Bind the values back to the model you specify.
<form:form method="post" action="addContact.html">
<table>
<tr>
<td><form:label path="firstname">First Name</form:label></td>
<td><form:input path="firstname" /></td>
</tr>
...
#RequestMapping(value = "/addContact", method = RequestMethod.POST)
public String addContact(#ModelAttribute("contact")
Contact contact, BindingResult result) {
See this Post: http://viralpatel.net/blogs/spring-3-mvc-handling-forms/

You might want to consider giving id to each and nested tags to differentiate between row that you want to POST
<c:forEach items="${searchResults}" var="searchResult">
<tr>
....
<form:form id="${searchResults.key}-form" method="POST" ACTION="./customercare">
<form:input id="${searchResults.key}-btn" type="SUBMIT" value="Select This Customer"/>
<form:input id="${searchResults.key}-hidden" type="hidden" name ="${searchResults.key}" value="searchResult['${searchResults.key}']"/>
</form:form>
</tr>
On the backend side you will have to write the controller as suggested by #PatBurke

You could have 1 form per customer with a lot of hidden inputs in. When that customer is selected you can POST that form. Spring can then bind all the hidden inputs to your customer object.
(Generally, I would just send the id only and load the customer info, as an entity, from a Database. However, I assume you must have a good reason for not wanting to do this)

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

Jsp form submit with list to spring MVC controller

I am new to jsp and spring MVC.
I had a jsp which display students list to take attendance with a checkbox in the form.
The Students jsp contains student details from student table and checkbox is from attendance table and my jsp page is like this
Jsp Code
<tr>
<th width="80">Student No</th>
<th width="120">Student Name</th>
<th width="120">Father Name</th>
<th width="60">Mobile No</th>
<th width="60">Present</th>
</tr>
<c:if test="${!empty studentsList}">
<c:forEach items="${studentsList}" var="student">
<tr>
<td>${student.studentId}</td>
<td>${student.studentName}</td>
<td>${student.fatherName}</td>
<td>${student.mobileNo}</td>
<td><form:checkbox path="attendance.presentFlag" /></td>
</c:forEach>
</c:if>
</table>
<div align="center">
<tr>
<td></td>
<td><input type="submit" value="Present" style="margin-top: 12px;"/></td>
</tr>
</div>
</form:form>
Above jsp will display list of students with a checkbox.
Now I want to submit the modified list in jsp to spring MVC controller to store in database based on the checkbox checked flag, can any one please suggest me how to overcome jsp form submission to spring mvc, I am unable to get what to do. I am able to call a method of controller what I have do for list submission.
Create a button instead of submit and call a java script function and then submit the form after applying your logic.
You need few things inside form tag:
method="GET/POST"
action="${request.contextPath}/requestMapping"
modelAttribute="attendance"
<form:checkbox path="presentFlag" /> -> will autobind value if attendance object have array of booleans "presentFlag"
Submit name and value determine request parameter with name and value respectively.
Your Spring controller should have request mapping same as in action, as well as request parameter and model attribute "attendance".
https://www.mkyong.com/spring-mvc/spring-mvc-checkbox-and-checkboxes-example/

On refreshing jsp page got submited again

I have created simple jsp servlet project on that when i submitting jsp form it insert data to specified table but after that when i refersh same jsp form get submitted and same data inserted to table..
ItemUnit.jsp
<form method="POST" action='ItemUnitHandler' name="frmAddUser">
<input type="hidden" name="action" value="insert" />
<table style="width:95%;margin-top:70px;" align="center">
<tr>
<td style="width:10%"> </td>
<td style="width:30%" align="right">Item Unit :</td>
<td style="width:2%"> </td>
<td style="width:40%" align="left"><input type="text" name="itemUnitName" style="width:200px;" /></td>
<td style="width:18%"> </td>
</tr>
<tr><td colspan="5"> </td></tr>
<tr>
<td colspan="5" align="center">
<input type="submit" class="button-2" value="Insert"></input>
<input type="reset" class="button-2" value="Reset"></input>
</td>
</tr>
</table>
</form>
Servlet post method code..
String action = request.getParameter("action");
System.out.println("action :action action : "+action);
if(action == null)
{
redirect = "ItemUnit.jsp";
}
else if(action.equalsIgnoreCase("insert"))
{
ItemUnit objItemUnit = new ItemUnit();
// System.out.println("request.getParameter : "+request.getParameter("itemUnitName"));
objItemUnit.setItemUnit(request.getParameter("itemUnitName"));
dao.addItemUnit(objItemUnit);
redirect = "ItemUnit.jsp";
}
please help me out from this problem...
Ideally, you should land on a static result page, instead of displaying the input form again. The idea is to force the browser to switch to a new URL so that a refresh will not re-trigger another data update. This is the simplest fix.
But if you prefer to use the same screen, you should use a hidden token. You must record some state since you want to differentiate 2 requests from one another: first and second request (the refresh).
Within your logic, plant a token the first time you display the input form. On any incoming request from the same session, check if you have used the token already and use it to determine if this is a second-time request. The diagram below will illustrate it further.
Setup
Processing

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

How to use session in JSP pages to get information?

I have a JSP page used for editing some user's info. When a user logins to the website, I keep the information in the session, then in my edit page I try the following:
<%! String username=session.getAttribute("username"); %>
<form action="editinfo" method="post">
<table>
<tr>
<td>Username: </td><td> <input type="text" value="<%=username %>" /> </td>
</tr>
</table>
</form>
but it gives error saying session cannot be resolved. What can I do about it?
JSP implicit objects likes session, request etc. are not available inside JSP declaration <%! %> tags.
You could use it directly in your expression as
<td>Username: </td>
<td><input type="text" value="<%= session.getAttribute("username") %>" /></td>
On other note, using scriptlets in JSP has been long deprecated. Use of EL (expression language) and JSTL tags is highly recommended. For example, here you could use EL as
<td>Username: </td>
<td><input type="text" value="${username}" /></td>
The best part is that scope resolution is done automatically. So, here username could come from page, or request, or session, or application scopes in that order. If for a particular instance you need to override this because of a name collision you can explicitly specify the scope as
<td><input type="text" value="${requestScope.username}" /></td> or,
<td><input type="text" value="${sessionScope.username}" /></td> or,
<td><input type="text" value="${applicationScope.username}" /></td>
Use
<% String username = (String)request.getSession().getAttribute(...); %>
Note that your use of <%! ... %> is translated to class-level, but request is only available in the service() method of the translated servlet.
See how JSP code is translated to a servlet.
The reason why you are getting the compilation error is, you are trying to access the session in declaration block (<%! %>) where it is not available. All the implicit objects of jsp are available in service method only. Code of declarative blocks goes outside the service method.
I'd advice you to use EL. It is a simplified approach.
${sessionScope.username} would give you the desired output.
Suppose you want to use, say ID in any other webpage then you can do it by following code snippet :
String id=(String)session.getAttribute("uid");
Here uid is the attribute in which you have stored the ID earlier. You can set it by:
session.setAttribute("uid",id);
<%! String username=(String)session.getAttribute("username"); %>
form action="editinfo" method="post">
<table>
<tr>
<td>Username: </td><td> <input type="text" value="<%=username %>" /> </td>
</tr>
</table>
add <%! String username=(String)session.getAttribute("username"); %>
You can directly use (String)session.getAttribute("username"); inside scriptlet tag ie <% %>.
form action="editinfo" method="post">
<table>
<tr>
<td>Username:</td>
<td>
<input type="text" value="<%if( request.getSession().getAttribute(" parameter_whatever_you_passed ") != null
{
request.getSession().getAttribute("parameter_whatever_you_passed ").toString();
}
%>" />
</td>
</tr>
</table>
</form>

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