Getting HTTP Request Headers in a JSP

By: Bruce W. Perry Printer Friendly Format

The JSTL v1.0 makes all existing request headers available via the header implicit object. The JSTL automatically makes this variable available to JSPs; the header object evaluates to a java.util.Map type.

In sample program below, the c:forEach tag iterates over this Map and stores each header name and value in the loop variable named by c:forEach's var attribute. The c:forEach var attribute is implemented as a java.util.Map.Entry type, which is a data type that stores keys and their values. The c:out tag displays each header name by using EL format: ${req.key}. Consequently c:out displays the value with ${req.value}.

Viewing the request header names and values in a JSP

<%@ taglib uri="http://java.sun.com/jstl/core" prefix="c" %>

<html>
<head><title>Request Headers</title></head>
<body>
<h2>Here are the Request Header names and values</h2>

<c:forEach var="req" items="${header}">

    <strong><c:out value=
        "${req.key}"/></strong>: <c:out value="${req.value}"/><br>

</c:forEach>

</body>
</html>

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