Re: Problem with EL (Expression Language) in JST /JSP

From:

"Lee Crawford" <lee.crawford@gmail.com>

Newsgroups:

comp.lang.java.programmer

Date:

29 Dec 2006 16:33:24 -0800

Message-ID:

<1167438804.131905.40950@73g2000cwn.googlegroups.com>

I think the problem is that the forEach tag is generating a numeric
type for the clientnum variable and the ${clients[clientnum]} syntax is
failing to interpret the expression correctly because it can't use an
int to index a map and isn't making the leap to try and coerce the
value to a string. If you convert the clientnum to a string explicitly
it will work:

Add this at the top:

 <%@ taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/functions"
%>

and use:

 Value: ${clients[fn:toLowerCase (clientnum)]}

alternately, if the only information being carrier in the map keys is
an integer perhaps a List would do?

<%
 final List clients = new ArrayList ();
 clients.add ("John");
 clients.add ("Peter");
 clients.add ("Gerald");
 request.setAttribute ("clients", clients);
%>

<c:forEach var="client" varStatus="status" items="${clients}">
 ${status.count}: '${client}' 
</c:forEach>

--lee

jgmaux@telefonica.net wrote:

Thanks, Steve.

I try your solution, but I have same problem.....

Steve ha escrito:

The problem is with the nested expressions, which you shouldn't need. I
think that

Value:${requestScope.clients[clientnum]}

should do the trick.

jgmaux@telefonica.net wrote:

Hi,

I have a problem with JSTL EL (Expression Language) in JSP.

The follow example show my problem.:

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<body>
<%
 java.util.HashMap clients = new java.util.HashMap();
 clients.put("1","John");
 clients.put("2","Peter");
 clients.put("3","Gerald");
 clients.put("4","Nick");
 request.setAttribute("clients",clients);
%>
<c:forEach var='clientnum' begin='1' end='4'>
 
 Client N=BA::${clientnum}
 
 
 Value:${requestScope.clients["${clientnum}"]}
 
</c:forEach>
</body>
</html>

My code don't display the "clients" values...
=BFWhere is the problem?
I don't want to use iteration, please....
Thanks in advance.