Spring MVC映射具有相同名称的多个动态表单元素

Question

I have a Spring MVC application and I am wondering how to successfully map multiple, dynamic form elements with the same name in my JSP page to my object class. For example:

In my locations.jsp page, I have multiple dropdown boxes:

<form id="tabs-3-form">
    <input id="locations-1" name="location" />
    <input id="locations-2" name="location" />
    <input id="locations-3" name="location" />
    ... (more can be added or deleted dynamically by user)
</form>

I'm using jQuery to POST the form to my controller:

$("#tabs-3-form").submit(function() {
    $.ajax({
        type: 'POST',
        url: '/searchResults',
        data: $(this).serialize(),
        dataType: 'json',
        success: function(data) {
           ...
        }
    });
    return false;
});

My LocationsController.java is set up as follows:

@RequestMapping(value = "/locationResults", method = RequestMethod.POST)
public @ResponseBody LocationsCollection locationsCollection
(
    @ModelAttribute(value = "location") Location location,
    BindingResult result
) 
{   
    LocationsCollection locationsCollection = new LocationsCollection();
    locationsCollection.addLocation(location);

    // Anything else to do here?

    return locationsCollection;
}

LocationsCollection.java just contains a List of Location objects.

Do I need to add brackets to the names of my input fields? Will MVC automatically do the mapping to a List, as it does with the other form elements? If anyone could provide an example, I'd appreciate it.

Answer 1

I was able to get it working by following the example from: http://lifeinide.blogspot.com/2010/12/dynamic-forms-lazylist-and-transparent.html?showComment=1355160197390#c6923871316812590644

I did make one adjustment, however. For the form names, I used:

<input name="locationList[0].locationName" />

instead of what the article suggests:

<input name="myFormObject.elements[0].property" />

Answer 2

I think you need to use brackets if you are using same name for form elements.

<c:forEach items="${expenseForm.expenseDetails}" varStatus="i">
  <tr id="expenseDetail_${i.index}" class="lineItemsClass" lineNum="${i.index}">
    <td><form:input path="expenseDetails[${i.index}].description" cssStyle="width: 200px;" /> <label style="color: red;"><form:errors path="expenseDetails[${i.index}].description" /></label></td>
    <td><form:input path="expenseDetails[${i.index}].quantity" cssStyle="width: 60px;" readonly="true"/> <label style="color: red;"><form:errors path="expenseDetails[${i.index}].quantity" /></label></td>
    <td><form:input path="expenseDetails[${i.index}].unitPrice" cssStyle="width: 60px;" readonly="true"/> <label style="color: red;"><form:errors path="expenseDetails[${i.index}].unitPrice" /></label></td>
    <td><form:input path="expenseDetails[${i.index}].total" cssStyle="width: 60px;" /> <label style="color: red;"><form:errors path="expenseDetails[${i.index}].total" /></label></td>
  </tr>
</c:forEach>

Here expenseDetails is the list in the modelAttribute class. The path name will be used as html form name and it will be indexed based. The above code segment is working fine for me.