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| 2 | Licensed to the Apache Software Foundation (ASF) under one or more | 
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| 3 | contributor license agreements.  See the NOTICE file distributed with | 
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| 5 | The ASF licenses this file to You under the Apache License, Version 2.0 | 
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| 6 | (the "License"); you may not use this file except in compliance with | 
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| 9 | http://www.apache.org/licenses/LICENSE-2.0 | 
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| 16 | --> | 
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| 17 | <%@ taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/functions" %> | 
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| 18 |  | 
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| 19 | <html> | 
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| 20 | <head> | 
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| 21 | <title>JSP 2.0 Expression Language - Implicit Objects</title> | 
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| 22 | </head> | 
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| 23 | <body> | 
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| 24 | <h1>JSP 2.0 Expression Language - Implicit Objects</h1> | 
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| 25 | <hr> | 
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| 26 | This example illustrates some of the implicit objects available | 
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| 27 | in the Expression Lanaguage.  The following implicit objects are | 
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| 28 | available (not all illustrated here): | 
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| 29 | <ul> | 
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| 30 | <li>pageContext - the PageContext object</li> | 
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| 31 | <li>pageScope - a Map that maps page-scoped attribute names to | 
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| 32 | their values</li> | 
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| 33 | <li>requestScope - a Map that maps request-scoped attribute names | 
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| 34 | to their values</li> | 
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| 35 | <li>sessionScope - a Map that maps session-scoped attribute names | 
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| 36 | to their values</li> | 
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| 37 | <li>applicationScope - a Map that maps application-scoped attribute | 
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| 38 | names to their values</li> | 
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| 39 | <li>param - a Map that maps parameter names to a single String | 
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| 40 | parameter value</li> | 
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| 41 | <li>paramValues - a Map that maps parameter names to a String[] of | 
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| 42 | all values for that parameter</li> | 
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| 43 | <li>header - a Map that maps header names to a single String | 
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| 44 | header value</li> | 
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| 45 | <li>headerValues - a Map that maps header names to a String[] of | 
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| 46 | all values for that header</li> | 
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| 47 | <li>initParam - a Map that maps context initialization parameter | 
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| 48 | names to their String parameter value</li> | 
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| 49 | <li>cookie - a Map that maps cookie names to a single Cookie object.</li> | 
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| 50 | </ul> | 
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| 51 |  | 
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| 52 | <blockquote> | 
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| 53 | <u><b>Change Parameter</b></u> | 
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| 54 | <form action="implicit-objects.jsp" method="GET"> | 
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| 55 | foo = <input type="text" name="foo" value="${fn:escapeXml(param["foo"])}"> | 
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| 56 | <input type="submit"> | 
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| 57 | </form> | 
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| 58 | <br> | 
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| 59 | <code> | 
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| 60 | <table border="1"> | 
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| 61 | <thead> | 
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| 62 | <td><b>EL Expression</b></td> | 
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| 63 | <td><b>Result</b></td> | 
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| 64 | </thead> | 
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| 65 | <tr> | 
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| 66 | <td>\${param.foo}</td> | 
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| 67 | <td>${fn:escapeXml(param["foo"])} </td> | 
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| 68 | </tr> | 
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| 69 | <tr> | 
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| 70 | <td>\${param["foo"]}</td> | 
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| 71 | <td>${fn:escapeXml(param["foo"])} </td> | 
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| 72 | </tr> | 
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| 73 | <tr> | 
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| 74 | <td>\${header["host"]}</td> | 
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| 75 | <td>${fn:escapeXml(header["host"])} </td> | 
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| 76 | </tr> | 
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| 77 | <tr> | 
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| 78 | <td>\${header["accept"]}</td> | 
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| 79 | <td>${fn:escapeXml(header["accept"])} </td> | 
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| 80 | </tr> | 
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| 81 | <tr> | 
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| 82 | <td>\${header["user-agent"]}</td> | 
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| 83 | <td>${fn:escapeXml(header["user-agent"])} </td> | 
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| 84 | </tr> | 
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| 85 | </table> | 
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| 86 | </code> | 
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| 87 | </blockquote> | 
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| 88 | </body> | 
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| 89 | </html> | 
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