如何在JSP中禁用几行的EL表达式

Question

In some JSP pages, I want to the page display

<h4>${id}</h4>

However, EL will try to evaluate "id" variable and leave it to blank(not find the variable) or the actual value.

 <h4>123</h4>

I know there is a

<%@ page isELIgnored="false" %>

but this will disable EL for the whole JSP page.

Is there any way to disable EL just for a few lines?

Thanks guys, I also write a post about this. http://www.ke-cai.net/2010/12/jquery-template-markup-and-jsp.html

Answer 1

Backslash is the easiest.

<h4>\${id}</h4>

Edit: I have used this method in conjunction with the offical jQuery Template plugin which has variables of the same syntax.

Answer 2

From the JSP 2.0 spec :

Quoting in EL Expressions

• There is no special quoting mechanism within EL expressions; use a literal '${' if the literal ${ is desired and expressions are enabled for the page. For example, the evaluation of ${'${'} is '${' . Note that ${'}'} is legal, and simply evaluates to '}' .

So in your case, instead of:

<h4>${id}</h4>

do this:

<h4>${'${'}id}</h4>

It certainly doesn't look pretty but it's what the Java Community Process settled on.

Answer 3

将$表示为HTML / XML实体。

<h1>&#36;{id}</h1>