Re: JSP and hashmap's containsKey

From:
=?ISO-8859-1?Q?Arne_Vajh=F8j?= <arne@vajhoej.dk>
Newsgroups:
comp.lang.java.programmer
Date:
Tue, 05 May 2009 21:54:26 -0400
Message-ID:
<4a00edcd$0$90276$14726298@news.sunsite.dk>
Lew wrote:

Lew wrote:

Try this (untested here):

 <c:if ${ ! empty myMap["keyValue"]} >


that should be

   <c:if test='${ ! empty myMap["keyValue"]}' >

   <c:out value='${myMap["keyValue"]}' />
 </c:if>


There are plenty of alternatives anyway. See demo below.

Arne

===============================================

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%@ page import="java.util.*" %>
<%
Map m = new HashMap();
m.put("k", "val");
request.setAttribute("m", m);
%>
Lew:
<c:if test='${! empty m["k"]}' >
     <c:out value='${m["k"]}' />
</c:if>
<br>
Alternative 1:
<c:if test='${m["k"] != null}' >
    <c:out value='${m["k"]}' />
</c:if>
<br>
Alternative 2:
<c:if test='${! empty m.k}' >
    <c:out value='${m.k}' />
</c:if>
<br>
Alternative 3:
<c:if test='${m.k != null}' >
    <c:out value='${m.k}' />
</c:if>
<br>
Alternative 4:
<c:out value='${m["k"]}' default=''/>
<br>
Alternative 5:
<c:out value='${m.k}' default=''/>
<br>
Alternative 6:
<c:out value='${m["k"]}' />
<br>
Alternative 7:
<c:out value='${m.k}' />
<br>
Alternative 8:
${m["k"] != null ? m["k"] : ""}
<br>
Alternative 9:
${m.k != null ? m.k : ""}
<br>
Alternative 10:
${m["k"]}
<br>
Alternative 11:
${m.k}

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