Render HTML conditionally in Spring MVC

问题:

Is there any tag which lets to render the HTML blocks conditionally. For e.g.: Struts has:

<logic:present name="someForm" property="someProperty">
    //Code block
</logic:present>

For e.g.: JSF has:

<h:panelGrid rendered="#{not empty someList}">
    //Some code block
</h:panelGrid>

Is there anything like that in spring MVC?

回答1:

Plain old JSTL to your rescue!

The beauty of Spring MVC is that it doesn't add tons of redundant tag libraries unlike other frameworks. You can always rely on JSTL for such checks which is part of the JSP spec now.

<c:if test="${not empty someList}">

</c:if>

回答2:

The JSTL:

<c:if test="${!empty someForm.someProperty}">

</c:if>

回答3:

you could use the common JSP/JSTL taglibs

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>

<c:choose>
        <c:when test="${condition}">
            something
        </c:when>
        <c:otherwise>
            something else
        </c:otherwise>
    </c:choose>

alternatively

<c:if test="${condition}">
        something
    </c:if>

using c:if there is no else condition as far as i know