fmt:parseNumber

[Eddie Barna]

I thought it would be fun to use JSTL for some form validation instead of Javascript. 
I am trying to make sure a user only enters numbers in a field called AcctNum. Also i 
decided to use <fmt:parseNumber /> to test my field. Here's the code:

<c:catch var="parsingError">

<fmt:parseNumber var="Gotcha" value="${param.AcctNum}"/>

</c:catch>

<c:if test="${Gotcha != param.AcctNum}" var="noMatch"/>



Now here's where i run into problems. if i input a string followed by numbers such as 
iu789 then my catch statement catches the error and stores the following statement in 
in my variable:

javax.servlet.jsp.JspException: In &lt;parseNumber&gt;, value attribute can not be 
parsed: "iu789"

This good. Thats what i am trying to do.

Now if i input something like this: 45678uy78 or number followed by a string such as 
this: 89087yht then the whole page craps out on me and i get this error from the 
server:

org.apache.jasper.JasperException: javax.servlet.jsp.JspException: An error occurred 
while evaluating custom action attribute "test" with value "${Gotcha == 
param.AcctNum}": An exception occured trying to convert String "45678uy78" to type 
"java.lang.Long" (null) at 
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:248) 

My understanding is that my catch statement is supposed to catch this also but it 
doesn't. Am I missing something here guys? Please be gentle since i am a novice. TIA