在 JSP 中，输入标记中的路径和值属性有何作用？表单前缀如何影响它们？
只是想要一个直接问题的明确答案 - 谷歌结果到处都是，或者没有解决您将在下面看到的组合。
我通常是一个 JSP 新手，一直在使用以下代码。
<form:input id="theId" path="path.copied.directly.fromSomewhereElse"
cssClass="contentTextInput" cssStyle="width: 229px" />
当我将其放入 JSP 页面并加载我的网站时，它工作正常并且看起来像我的 cssClass 定义的那样。然后我开始搞乱它，因为我希望它显示默认的值。
<form:input id="theId" path="path.copied.directly.fromSomewhereElse"
value="blah" cssClass="contentTextInput" cssStyle="width: 229px" />
突然，HTTP 500，一个 org.apache.jasper.JasperException！因此，我决定完全删除路径，同时保留值。由于之前的经验，这只是我知道有效的方法的第一步。现在的代码是：
<form:input id="theId" value="someClass.valueIWantAsDefault"
cssClass="contentTextInput" cssStyle="width: 229px" />
这实际上也引发了异常 - 但后来我删除了表单前缀并且它基本上起作用了。你看，cssClass 的效果现在消失了；它看起来像一个常规的、不受影响的输入文本框。这是到目前为止的代码。
<input id="theId" value="someClass.valueIWantAsDefault"
cssClass="contentTextInput" cssStyle="width: 229px" />
这些属性（和前缀）到底做了什么才能使这种混合搭配发挥作用？
Just wanted a clear answer for a direct question -- google results have been all over the place or don't address the combos you'll see below.
I'm generally a JSP newbie and have been screwing around with the following code.
<form:input id="theId" path="path.copied.directly.fromSomewhereElse"
cssClass="contentTextInput" cssStyle="width: 229px" />
When I put that into my JSP page and load my website, it works fine and looks as my cssClass defines it. Then I start messing with it because I want it to display a default value.
<form:input id="theId" path="path.copied.directly.fromSomewhereElse"
value="blah" cssClass="contentTextInput" cssStyle="width: 229px" />
Suddenly, HTTP 500, an org.apache.jasper.JasperException! So I decide to remove the path altogether, while leaving in the value. This is just step 1 in something I know works because of prior experience. The code is now:
<form:input id="theId" value="someClass.valueIWantAsDefault"
cssClass="contentTextInput" cssStyle="width: 229px" />
That actually throws an exception, too -- but then I remove the form prefix and it works-- mostly. You see, the cssClass's effects are now gone; it looks like a regular, unaffected input textbox. Here's the code so far.
<input id="theId" value="someClass.valueIWantAsDefault"
cssClass="contentTextInput" cssStyle="width: 229px" />
What exactly do these attributes (and prefix) do that makes this mix-and-match work?
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我猜您正在处理一个依赖于 JSP 自定义标记库的 jsp 页面，该标记库是 Spring 框架的一部分。以下是
value不是此自定义标记的有效属性，您可以在我上面提供的文档链接中看到。当您删除form:时，您会将标记转换为普通的旧 HTML标记，这就是您的错误此时消失的原因。这也是你的 css 停止工作的原因。cssClass不是 HTML标记的正确属性。它只是类。他们在 jsp 自定义标记库中将其称为cssClass，最有可能避免与Object.getClass()方法发生较低级别的冲突（长话短说，请相信我的话） ）。I'm guessing you're dealing with a jsp page that relies on a JSP custom tag library that's part of the Spring Framework. Here are the docs for the
<form:input>tag.valueis not a valid attribute for this custom tag as you can see in the docs link I provided above. When you remove theform:, you're turning the tag into a plain old HTML<input>tag which is why your error is going away at that point. It's also why your css stops working.cssClassis not the correct attribute for the HTML<input>tag. It's simplyclass. They called itcssClassin the jsp custom tag lib most likely to avoid a lower level collision with theObject.getClass()method (long story, just take my word for it).