HTML未通过验证

Question

The below line is not passing validation in my application. The error is in Netbeans is...

Bad value " /content/edit" for attribute href on element "a": WHITESPACE in PATH

    <a href="<%=request.getAttribute("urlPrefix")%>/content/edit">Add Content</a>

The runtime error is:

org.apache.jasper.JasperException: /base.jsp(9,25) PWC6213: quote symbol expected

I am passing an attribute for this value. Why am I getting this error when I pass a value?

Answer 1

Don't use scriptlets in JSP. Use the JSP EL:

<a href="${urlPrefix}/content/edit">Add Content</a>

Answer 2

<a href="<%=request.getAttribute('urlPrefix')%>/content/edit">Add Content</a>

Use single quotes with urlPrefix . It should work.

Answer 3

Try this:

<% String urlPrefix = (String)request.getAttribute("urlPrefix"); %>
<a href="<%=urlPrefix%>/content/edit">Add Content</a>

or better this:

<%
String urlPrefix = (String)request.getAttribute("urlPrefix");
String url = urlPrefix + "/content/edit";
%>
<a href="<%=url%>">Add Content</a>

or even better use EL:

<a href="${urlPrefix}/content/edit">Add Content</a>

It's worth mentioning the protection against XSS attacks as Asaph pointed out in his comment:

<a href="${fn:escapeXml(urlPrefix)}/content/edit">Add Content</a>

might do the trick if you include

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

at the top of your JSP.

Answer 4

I've just done a simple test and the following line has no syntax error and runs without throwing an exception whether the urlPrefix attribute is set or not:

<a href="<%=request.getAttribute("urlPrefix")%>/content/edit">Add Content</a>

There is no syntax error at all. In the case of there being no urlPrefix attribute set, the resulting html is:

<a href="null/content/edit">Add Content</a>

In the case of urlPrefix being equal to http://example.com , the resulting html is:

<a href="http://example.com/content/edit">Add Content</a>

Here is a quick little standalone test.jsp file to demonstrate:

<% request.setAttribute("urlPrefix", "http://example.com"); %>
<a href="<%=request.getAttribute("urlPrefix")%>/content/edit">Add Content</a>

You can remove the first line to test the null case.

So we've demonstrated that the line you posted as the alleged offending line is not actually problematic. Some possibilities:

1. Are you sure you're looking at the correct line?
2. Are you sure you're looking at the correct file?
3. Are you sure you've deployed your application?
4. Are you sure you're looking at the correct url/environment?