如何使用Spring将列表中的输入值绑定到bean属性

Question

I need to bind an object with a list of objects as an attribute. It is a static list and it is created and partially filled in the Controller. It is displayed correctly in the view, however the value in the input field is not set when the form is sent to the controller. I did some research and found several similar questions, however none of the proposed solutions worked for me.

edit.jsp

<c:forEach items="${priceConfigurationForm.priceList}" var="price" varStatus="priceStatus">
                    <tr>
                        <td>
                            <spring:bind path="priceConfigurationForm.priceList[${priceStatus.index}].country">
                                ${price.country}
                                <input type="hidden" name="<c:out value="${status.expression}"/>"
                                       id="<c:out value="${status.expression}"/>"
                                       value="<c:out value="${status.value}"/>"/>
                            </spring:bind>
                        </td>

                        <td>
                            <spring:bind path="priceConfigurationForm.priceList[${priceStatus.index}].amount">
                                <input type="text" name="price" value="${price.amount}"/>
                                <input type="hidden"
                                       name="<c:out value="${status.expression}"/>"
                                       id="<c:out value="${status.expression}"/>"
                                       value="<c:out value="${status.value}"/>"/>
                            </spring:bind>
                        </td>

                        <td>
                            <spring:bind path="priceConfigurationForm.priceList[${priceStatus.index}].currency">
                                ${price.currency}
                                <input type="hidden" name="<c:out value="${status.expression}"/>"
                                       id="<c:out value="${status.expression}"/>"
                                       value="<c:out value="${status.value}"/>"/>
                            </spring:bind>
                        </td>
                    </tr>
                </c:forEach>

Abstract from Controller populating the list:

@RequestMapping(value = "/price/create", method = RequestMethod.GET)
    public String toCreatePriceConfiguratioView(Model model) {

        log.info("::createPriceConfiguration: {}");

        final PriceConfigurationForm priceConfigurationForm = new PriceConfigurationForm();

        final List<PriceConfigurationForm.Price> prices = new ArrayList<>();
        for (Country country : Country.values()) {
            PriceConfigurationForm.Price price = new PriceConfigurationForm.Price();
            price.setAmount(100);
            price.setCountry(country.getCountryCode());
            price.setCurrency(country.getCurrency());
            prices.add(price);
        }

        priceConfigurationForm.setPriceList(prices);

        model.addAttribute("priceConfigurationForm", priceConfigurationForm);

        return "/secured/sources/onboarding/price/edit";
    }

Abstract from Controller for storing the list:

@RequestMapping(value = "/price/create", method = RequestMethod.POST)
    public String createPriceConfiguration(Model model, @ModelAttribute("priceConfigurationForm") @Valid PriceConfigurationForm priceConfigurationForm, BindingResult bindingResult, RedirectAttributes attributes) {

        log.info("::createPriceConfiguration {}", priceConfigurationForm);
        // TODO: Validate, before create

        /* transform form to domain object */
        PriceConfiguration configuration = PriceConfigurationForm.toPriceConfiguration(priceConfigurationForm);
        onboardingApi.createPriceConfiguration(configuration);

        attributes.addFlashAttribute("message", success("price configuration saved", priceConfigurationForm.getName()));
        return "/secured/sources/onboarding/price/index";
    }

Object:

@Data
public class PriceConfigurationForm {

    private String name;

    private String description;

    private List<Price> priceList;

    private Map<String, Long> countryToPriceMap;

    public static PriceConfiguration toPriceConfiguration(PriceConfigurationForm form) {
        final PriceConfiguration pc = new PriceConfiguration();
        pc.setName(form.getName());
        pc.setDescription(form.getDescription());
        final Map<String, Long> prices = form.getPriceList().stream().collect(toMap(Price::getCountry, Price::getAmount));
        pc.setCountryToPriceMap(prices);
        return pc;
    }

    @Data
    public static class Price {
        private String country;
        private long amount;
        private String currency;
    }
}

Answer 1

This is example of how I sucessfully parsed nested objects in one project :

<c:forEach var="block" items="${newplaceform.blocks}" varStatus="counter">
        <fieldset data-block-order="${counter.index}" data-block-index="${counter.index}">
<c:if test='${block.type=="quizSingleAnswer"}'>
            <legend><s:message code='blocks.type.quizSingleAnswer'/> <a class="glyphicon glyphicon-move move-block pull-right" href="#"></a><a data-remove="block" class="glyphicon glyphicon-remove pull-right" href="#"></a><a data-reordering="up" class="glyphicon glyphicon-chevron-up pull-right" href="#"></a><a data-reordering="down" class="glyphicon glyphicon-chevron-down pull-right" href="#"></a></legend>
            <div class="form-group production-hide">
                <label class="col-sm-3 control-label">id:</label>
                <div class="col-sm-9"><input type="text" name="blocks[${counter.index}].id" value="${block.id}" data-row="blockId" data-disabled class="form-control"/></div>
            </div>
            <div class="form-group production-hide">
                <label class="col-sm-3 control-label">type:</label>
                <div class="col-sm-9"><input type="text" name="blocks[${counter.index}].type" value="${block.type}" data-disabled class="form-control"/></div>
            </div>
            <div class="form-group">
                <label class="col-sm-3 control-label"><s:message code='blocks.description'/>:</label>
                <div class="col-sm-9"><textarea class="form-control" name="blocks[${counter.index}].description" data-description rows="3">${block.description}</textarea></div>
            </div>
            <div class="row">
                <div class="col-sm-6">
                    <div class="col-sm-6 control-label">
                        <label class="inner-header"><s:message code='blocks.answers'/>:</label>
                    </div>
                    <div class="col-sm-6">
                        <div class="btn-group m-t-9">
                            <a class="btn btn-primary btn-xs" href="#" data-add-answer data-add-answer-block-index="${counter.index}"><i class="glyphicon glyphicon-plus"></i> <s:message code="blocks.add-answer" /></a>
                        </div>
                    </div>
                </div>
            </div>
            <div class="row quiz-answers" data-count-answer="${block.answers.size()}">
                <c:forEach var="answer" items="${block.answers}" varStatus="counterInner">
                    <div class="col-sm-6">
                        <fieldset>
                            <legend>
                                <div class="bootstrap-center">
                                    <span><s:message code="blocks.answerNo"/> ${counterInner.index+1}</span>
                                    <a data-remove="answer" class="glyphicon glyphicon-remove pull-right" href="#"></a>
                                </div>
                            </legend>
                            <div class="form-group production-hide">
                                <label class="col-sm-6 control-label">id:</label>
                                <div class="col-sm-6"><input type="text" name="blocks[${counter.index}].answers[${counterInner.index}].id" value="${answer.id}" data-row="answerId" data-disabled class="form-control"/></div>
                            </div>
                            <div class="form-group">
                                <label class="col-sm-6 control-label"><s:message code="blocks.answer"/>:</label>
                                <div class="col-sm-6"><input type="text" name="blocks[${counter.index}].answers[${counterInner.index}].text" value="${answer.text}" class="form-control"/></div>
                            </div>
                            <div class="form-group">
                                <div class="col-sm-6 col-sm-offset-6">
                                    <div class="checkbox">
                                        <label>
                                            <input type="checkbox" name="blocks[${counter.index}].answers[${counterInner.index}].right" value="true" ${answer.checked()}/>
                                            <s:message code="blocks.right"/>
                                        </label>
                                    </div>
                                </div>
                            </div>
                        </fieldset>
                    </div>
                </c:forEach>
            </div>