JSP 2.0 Expression Language - Functions


An upgrade from the JSTL expression language, the JSP 2.0 EL also allows for simple function invocation. Functions are defined by tag libraries and are implemented by a Java programmer as static methods.
Change Parameter
foo =

EL Expression Result
\${param["foo"]} ${fn:escapeXml(param["foo"])} 
\${my:reverse(param["foo"])} ${my:reverse(fn:escapeXml(param["foo"]))} 
\${my:reverse(my:reverse(param["foo"]))} ${my:reverse(my:reverse(fn:escapeXml(param["foo"])))} 
\${my:countVowels(param["foo"])} ${my:countVowels(fn:escapeXml(param["foo"]))}