Encoding Non-XML Data and Special Characters
Since a JSP Document is a formal XML document, all template data must
be well- formed XML. Example 17-10 is well-formed
because it contains XHTML elements, such as the
<ul>
and <li>
elements, represented by opening and closing tags, and an empty
<br/>
tag.
If you use a JSP Document to generate a response in a format that is
not XML-based, you can embed the template data that is not
well-formed in XML CDATA sections. For instance, if the response must
be accessible to older browsers that only understand HTML 3.2, you
can’t use the XHTML <br/>
empty tag syntax, but using HTML 3.2 syntax with a single opening
<br>
tag violates the well-formedness
requirement. Embedding the HTML 3.2 single opening
<br>
tag in a CDATA
section
solves the problem; it satisfies the
container’s well-formed XML requirement and feeds
the browser the HTML 3.2 tag it understands:
<ul>
<c:forEach items="${paramValues}" var="current">
<li>
${current.key}:
<c:forEach items="${current.value}" var="parValue">
<![CDATA[<br>]]>${parValue}
</c:forEach>
</li>
</c:forEach>
In an XML document, special characters such as greater-than and
less-than in an element body (or attribute) must be replaced with
character entity codes, for example, the <
character must be replaced with <
and
>
must be replaced with
>
. These characters are common in Java
code, so if you need to use scripting elements in a JSP Document, you
can use a CDATA section to work around this issue as well:
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