[OT?]JSP: Escape EL expressions

[Ashton]

I am trying to write some JSP code that uses JSTL. However, I also need
the output page to contain the actual string:

<cut value="${param.author}"/>

I've tried HTML tags, using the string as a value in another cut,
setting the string into a JSTL variable, but nothing seems to protect
the EL expression. I even tried putting it in its own file and using
jsp:include, but it looks like that also happens before tag evaluation.

The closest I've got is by using...

<cut value='<cut value="$\{param.author}"/>' escapeXml='false'/>

....but that's a bit too literal and doesn't see the '\' as an escape
character...inserts it verbatim in the response.

What am I missing?

(I suspect I could use entities to make the output *look* right in a
browser, but that's not the goal.)

 

[Ashton]

The closest I've got is by using...

<cut value='<cut value="$\{param.author}"/>' escapeXml='false'/>

Following up my own post....

Of course as soon as I posted that, a solution came to me. If I write
the text I want in chunks, without any one chunk having an EL
expression, no evaluation happens. As in:

<cut value='<cut value="$' escapeXml='false'/><cut
value='{param.author}"/>' escapeXml='false'/>

However, if anyone has a more elegant solution, I'd be happy to hear
about it. Thanks.

 

[Christophe Vanfleteren]

Following up my own post....

Of course as soon as I posted that, a solution came to me. If I write
the text I want in chunks, without any one chunk having an EL
expression, no evaluation happens. As in:

<cut value='<cut value="$' escapeXml='false'/><cut
value='{param.author}"/>' escapeXml='false'/>

However, if anyone has a more elegant solution, I'd be happy to hear
about it. Thanks.

From the JSP 2 spec:

For literal values that include the character sequence ${, JSP 2.0 provides a
way to escape them by using the sequence ${'${'. For example, the following
character sequence is translated into the literal value ${expr}:

${'${'}expr}