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e1066. Getting a Request Parameter Using JSTL in a JSP Page

When using the JSTL's expression language (see e1065 Enabling the JSTL Expression Language in a JSP Page), the request parameters are made available in the implicit object param. This example demonstrates how to include the value of a request parameter from the query string or posted data in the generated output:

    <%-- Declare the core library --%>
    <%@ taglib uri="/WEB-INF/tld/c.tld" prefix="c" %>
    
    <c:choose>
        <c:when test="${empty param.name}">
            Please enter your name.
        </c:when>
        <c:otherwise>
            Hello <b><c:out value="${param.name}" /></b>!
        </c:otherwise>
    </c:choose>

If the page was accessed with the URL:

    http://hostname.com/mywebapp/mypage.jsp?name=John+Smith

the resulting output would be:

    Hello <b>John Smith</b>!