java 如何在不使用表单标记库的情况下在 JSP 中访问 Spring 3 MVC 验证器结果
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How to access Spring 3 MVC validator results in JSP without using form taglib
提问by chubbsondubs
I have a simple Spring 3 MVC form using jsp taglibs. I need to add a class based on whether a field within the form has any errors associated with it or not. Here is a snipet of my HTML:
我有一个使用 jsp taglibs 的简单 Spring 3 MVC 表单。我需要根据表单中的字段是否有任何相关错误添加一个类。这是我的 HTML 片段：
<div class="control-group error"> <!-- HERE: binding.hasErrors() ? "error" : "" -->
<form:label path="username" cssClass="control-label">User Name</form:label>
<div class="controls">
<form:input path="username" cssClass="span3"/>
<form:errors path="username" cssClass="help-inline" />
</div>
</div>
So on the first line the class attribute has two classes "control-group" and "error". I need to add error class only if that field has an error associated with it. I know the WebDataBinder is included in the page somehow, but I don't know how to access it. Essentially I just want to execute some good old fashion <%= binding.hasError() ? "error" : "" %>, but how do I get access to the binder in the page?
所以在第一行类属性有两个类“控制组”和“错误”。仅当该字段有与之关联的错误时，我才需要添加错误类。我知道 WebDataBinder 以某种方式包含在页面中，但我不知道如何访问它。基本上我只想执行一些好的旧时尚 <%= binding.hasError() ？"error" : "" %>，但是如何访问页面中的活页夹？
采纳答案by chubbsondubs
While this is a little more obscure I think it's simpler because it's a single line which is what it would be if I were just using scriplets like any sane Java dev should. Taglibs need to die die die die, then die some more. They are horrible and I can't believe Java devs still think they actually help and not waste our utter time. PHP developers laugh at us when we use those things.
虽然这有点晦涩，但我认为它更简单，因为它是一行，如果我只是像任何理智的 Java 开发人员那样使用脚本，就会如此。Taglibs需要死死死死，然后再死一些。他们太可怕了，我不敢相信 Java 开发人员仍然认为他们真的有帮助而不是浪费我们的全部时间。当我们使用这些东西时，PHP 开发人员会嘲笑我们。
<div class="control-group ${requestScope['org.springframework.validation.BindingResult.user'].hasFieldErrors('firstName') ? 'error' : ''}">
回答by Xaerxess
Did you try <spring:hasBindErrors>tag (I don't understand what you mean writing "without using form taglib")?
您是否尝试过<spring:hasBindErrors>标记（我不明白您写“不使用表单 taglib”的意思）？
<%@ taglib prefix="spring" uri="http://www.springframework.org/tags"%>
<spring:hasBindErrors name="yourCommandName">
<c:if test="${errors.hasFieldErrors('username')}">
<c:set var="errorClass" value="error" />
</c:if>
</spring:hasBindErrors>
<div class="control-group <c:out value='${errorClass}' />">
Edit after comments:
评论后编辑：
Inside <spring:hasBindErrors>tag there is errorsvariable (see Errorsinterface) bound to actual binding errors. You can check if field has errors via errors.hasFieldErrors(fieldName).
<spring:hasBindErrors>标签内部有一个errors变量（见Errors接口）绑定到实际的绑定错误。您可以通过errors.hasFieldErrors(fieldName).
And really obscure way to get field errors without any tag is requestScope['org.springframework.validation.BindingResult.yourCommandName'].hasFieldErrors('username')...
在没有任何标签的情况下获取字段错误的真正晦涩的方法是requestScope['org.springframework.validation.BindingResult.yourCommandName'].hasFieldErrors('username')......
回答by java_dude
There is a better way to get the error message
有更好的方法来获取错误信息
<spring:hasBindErrors name="yourCommandName">
${errors.hasFieldErrors('userId') ? errors.getFieldError('userId').defaultMessage : ''}
</spring:hasBindErrors>
And one liner
和一个班轮
${requestScope['org.springframework.validation.BindingResult.user'].hasFieldErrors('emailId') ? requestScope['org.springframework.validation.BindingResult.user'].getFieldError('emailId').defaultMessage : ''}
