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gerjantd/list-objects.jsp

Created January 31, 2014 10:09
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List JSP implicit object
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list-objects.jsp
<!--
Licensed to the Apache Software Foundation (ASF) under one or more
contributor license agreements. See the NOTICE file distributed with
this work for additional information regarding copyright ownership.
The ASF licenses this file to You under the Apache License, Version 2.0
(the "License"); you may not use this file except in compliance with
the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
-->
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/fmt" prefix="fmt" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/functions" prefix="fn" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/sql" prefix="sql" %>
<html>
<head>
<title>JSP 2.0 Expression Language - Implicit Objects (Custom)</title>
</head>
<body>
<h1>JSP 2.0 Expression Language - Implicit Objects (Custom)</h1>
<hr>
<h2>pageScope</h2>
<code>
<table border="1">
<thead>
<td><b>Key</b></td>
<td><b>Value</b></td>
</thead>
<c:forEach var="pageScopeEntry" items="${pageScope}">
<tr>
<td>${pageScopeEntry.key}</td>
<td>${fn:escapeXml(pageScopeEntry.value)}&nbsp;</td>
</tr>
</c:forEach>
</table>
</code>
<h2>requestScope</h2>
<code>
<table border="1">
<thead>
<td><b>Key</b></td>
<td><b>Value</b></td>
</thead>
<c:forEach var="requestScopeEntry" items="${requestScope}">
<tr>
<td>${requestScopeEntry.key}</td>
<td>${fn:escapeXml(requestScopeEntry.value)}&nbsp;</td>
</tr>
</c:forEach>
</table>
</code>
<h2>sessionScope</h2>
<code>
<table border="1">
<thead>
<td><b>Key</b></td>
<td><b>Value</b></td>
</thead>
<c:forEach var="sessionScopeEntry" items="${sessionScope}">
<tr>
<td>${sessionScopeEntry.key}</td>
<td>${fn:escapeXml(sessionScopeEntry.value)}&nbsp;</td>
</tr>
</c:forEach>
</table>
</code>
<h2>applicationScope</h2>
<code>
<table border="1">
<thead>
<td><b>Key</b></td>
<td><b>Value</b></td>
</thead>
<c:forEach var="applicationScopeEntry" items="${applicationScope}">
<tr>
<td>${applicationScopeEntry.key}</td>
<td>
<c:catch var="applicationScopeEntryValueError">
${fn:escapeXml(applicationScopeEntry.value)}&nbsp;
</c:catch>
<c:if test="${not empty applicationScopeEntryValueError}">
Caught exception while trying to output applicationScopeEntry.value
</c:if>
</td>
</tr>
</c:forEach>
</table>
</code>
<h2>initParam</h2>
<code>
<table border="1">
<thead>
<td><b>Key</b></td>
<td><b>Value</b></td>
</thead>
<c:forEach var="initParamEntry" items="${initParam}">
<tr>
<td>${initParamEntry.key}</td>
<td>${fn:escapeXml(initParamEntry.value)}&nbsp;</td>
</tr>
</c:forEach>
</table>
</code>
<h2>header</h2>
<code>
<table border="1">
<thead>
<td><b>Key</b></td>
<td><b>Value</b></td>
</thead>
<c:forEach var="headerEntry" items="${header}">
<tr>
<td>${headerEntry.key}</td>
<td>${fn:escapeXml(headerEntry.value)}&nbsp;</td>
</tr>
</c:forEach>
</table>
</code>
<h2>param</h2>
<code>
<table border="1">
<thead>
<td><b>Key</b></td>
<td><b>Value</b></td>
</thead>
<c:forEach var="paramEntry" items="${param}">
<tr>
<td>${paramEntry.key}</td>
<td>${fn:escapeXml(paramEntry.value)}&nbsp;</td>
</tr>
</c:forEach>
</table>
</code>
<h2>cookie</h2>
<code>
<table border="1">
<thead>
<td><b>Key</b></td>
<td><b>Value</b></td>
</thead>
<c:forEach var="cookieEntry" items="${cookie}">
<tr>
<td>${cookieEntry.key}</td>
<td>${fn:escapeXml(cookieEntry.value)}&nbsp;</td>
</tr>
</c:forEach>
</table>
</code>
<hr>
This example illustrates some of the implicit objects available
in the Expression Lanaguage. The following implicit objects are
available (not all illustrated here):
<ul>
<li>pageContext - the PageContext object</li>
<li>pageScope - a Map that maps page-scoped attribute names to
their values</li>
<li>requestScope - a Map that maps request-scoped attribute names
to their values</li>
<li>sessionScope - a Map that maps session-scoped attribute names
to their values</li>
<li>applicationScope - a Map that maps application-scoped attribute
names to their values</li>
<li>param - a Map that maps parameter names to a single String
parameter value</li>
<li>paramValues - a Map that maps parameter names to a String[] of
all values for that parameter</li>
<li>header - a Map that maps header names to a single String
header value</li>
<li>headerValues - a Map that maps header names to a String[] of
all values for that header</li>
<li>initParam - a Map that maps context initialization parameter
names to their String parameter value</li>
<li>cookie - a Map that maps cookie names to a single Cookie object.</li>
</ul>
<blockquote>
<u><b>Change Parameter</b></u>
<form action="implicit-objects-custom.jsp" method="GET">
foo = <input type="text" name="foo" value="${fn:escapeXml(param["foo"])}">
<input type="submit">
</form>
<br>
<code>
<table border="1">
<thead>
<td><b>EL Expression</b></td>
<td><b>Result</b></td>
</thead>
<tr>
<td>\${param.foo}</td>
<td>${fn:escapeXml(param["foo"])}&nbsp;</td>
</tr>
<tr>
<td>\${param["foo"]}</td>
<td>${fn:escapeXml(param["foo"])}&nbsp;</td>
</tr>
<tr>
<td>\${header["host"]}</td>
<td>${fn:escapeXml(header["host"])}&nbsp;</td>
</tr>
<tr>
<td>\${header["accept"]}</td>
<td>${fn:escapeXml(header["accept"])}&nbsp;</td>
</tr>
<tr>
<td>\${header["user-agent"]}</td>
<td>${fn:escapeXml(header["user-agent"])}&nbsp;</td>
</tr>
</table>
</code>
</blockquote>
</body>
</html>
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