How to make fmt:formatDate work for form:input

问题

I have a jstl loop and I want to format the date of a form:input. I have tried many permutations of some of the suggestions that I've fond online but I just cannot get it to work.. Can someone please have a look?

I've included the full loop for context but the problem lies in the last <td></td> block.

<c:forEach items="${valueTransactionsModel.transactions}" var="transaction" varStatus="loopStatus">

                        <tr class="${loopStatus.index % 2 == 0 ? 'even' : 'odd'}">
                            <spring:message code="valueTransactions.transactionType" var="transactionTypeLbl" />
                            <tags:dropdown id="transactionTypeId${loopStatus.index}" path="transactions['${loopStatus.index}'].valueTransactionType.id" 
                                fieldName="${transactionTypeLbl}" classStyle="mandatory" items="${transactionTypes}" itemLabel="value"/>
                        </tr>
                        <tr class="${loopStatus.index % 2 == 0 ? 'even' : 'odd'}">
                            <spring:message code="valueTransactions.transactionAmount" var="valueTransactionAmountLbl${loopStatus.index}" />
                            <tags:input id="transactionAmountId${loopStatus.index}" 
                                path="transactions['${loopStatus.index}'].valueTransactionAmount"
                                fieldName="valueTransactionAmountLbl${loopStatus.index}"
                                maxlength="30" classStyle="mandatory" />
                            <spring:message code="valueTransactions.transactionDate"
                                var="valueTransactionDateLbl${loopStatus.index}" />
                            <td>
                                <form:input type="text" path="transactions['${loopStatus.index}'].valueTransactionDate" cssClass="mandatory" value="<fmt:formatDate value="transactions['${loopStatus.index}'].valueTransactionDate"  type="date" pattern="yyyy-MM-dd"/>" />
                            </td>
                        </tr> 


            </c:forEach>

My most recent issue is:

JSPG0055E: Unable to create an xml attribute from name [transactions[] value [${loopStatus.index}]

回答1:

You can't use a JSP tag in an attribute of another JSP tag. STore the result of the date formatting in a page attribute, and use this page attribute (as you would do with a variable in Java):

<fmt:formatDate value="transactions['${loopStatus.index}'].valueTransactionDate"  
                type="date" 
                pattern="yyyy-MM-dd"
                var="theFormattedDate" />
<form:input type="text" path="..." value="${theFormattedDate}"/>

回答2:

In the latest releases of the spring JSTL tags you can't use the attribute value into de tah form:input. If you try, you will get a value attribute is not valid for tag <form:input> error.

In this case you must use a normal HTML input tag and put the path as the name of the input to trigger the binding to the Spring form like this

<fmt:formatDate var="fmtDate" value="${form.bean.dateProperty}" pattern="dd/MM/yyyy"/>
<input type="text" name="bean.dateProperty" value="${fmtDate}"/>

Ugly but works for me! ;)

来源：https://stackoverflow.com/questions/11736150/how-to-make-fmtformatdate-work-for-forminput