1 | <html><body><pre> |
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3 | Licensed to the Apache Software Foundation (ASF) under one or more |
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14 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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15 | See the License for the specific language governing permissions and |
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16 | limitations under the License. |
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18 | <%@ taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/functions" %> |
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19 | |
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20 | <html> |
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21 | <head> |
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22 | <title>JSP 2.0 Expression Language - Implicit Objects</title> |
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23 | </head> |
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24 | <body> |
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25 | <h1>JSP 2.0 Expression Language - Implicit Objects</h1> |
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26 | <hr> |
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27 | This example illustrates some of the implicit objects available |
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28 | in the Expression Lanaguage. The following implicit objects are |
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29 | available (not all illustrated here): |
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30 | <ul> |
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31 | <li>pageContext - the PageContext object</li> |
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32 | <li>pageScope - a Map that maps page-scoped attribute names to |
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33 | their values</li> |
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34 | <li>requestScope - a Map that maps request-scoped attribute names |
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35 | to their values</li> |
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36 | <li>sessionScope - a Map that maps session-scoped attribute names |
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37 | to their values</li> |
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38 | <li>applicationScope - a Map that maps application-scoped attribute |
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39 | names to their values</li> |
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40 | <li>param - a Map that maps parameter names to a single String |
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41 | parameter value</li> |
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42 | <li>paramValues - a Map that maps parameter names to a String[] of |
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43 | all values for that parameter</li> |
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44 | <li>header - a Map that maps header names to a single String |
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45 | header value</li> |
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46 | <li>headerValues - a Map that maps header names to a String[] of |
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47 | all values for that header</li> |
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48 | <li>initParam - a Map that maps context initialization parameter |
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49 | names to their String parameter value</li> |
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50 | <li>cookie - a Map that maps cookie names to a single Cookie object.</li> |
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51 | </ul> |
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52 | |
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53 | <blockquote> |
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54 | <u><b>Change Parameter</b></u> |
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55 | <form action="implicit-objects.jsp" method="GET"> |
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56 | foo = <input type="text" name="foo" value="${fn:escapeXml(param["foo"])}"> |
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57 | <input type="submit"> |
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58 | </form> |
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59 | <br> |
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60 | <code> |
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61 | <table border="1"> |
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62 | <thead> |
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63 | <td><b>EL Expression</b></td> |
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64 | <td><b>Result</b></td> |
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65 | </thead> |
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66 | <tr> |
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67 | <td>\${param.foo}</td> |
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68 | <td>${fn:escapeXml(param["foo"])}&nbsp;</td> |
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69 | </tr> |
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70 | <tr> |
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71 | <td>\${param["foo"]}</td> |
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72 | <td>${fn:escapeXml(param["foo"])}&nbsp;</td> |
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73 | </tr> |
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74 | <tr> |
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75 | <td>\${header["host"]}</td> |
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76 | <td>${fn:escapeXml(header["host"])}&nbsp;</td> |
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77 | </tr> |
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78 | <tr> |
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79 | <td>\${header["accept"]}</td> |
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80 | <td>${fn:escapeXml(header["accept"])}&nbsp;</td> |
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81 | </tr> |
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82 | <tr> |
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83 | <td>\${header["user-agent"]}</td> |
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84 | <td>${fn:escapeXml(header["user-agent"])}&nbsp;</td> |
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85 | </tr> |
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86 | </table> |
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87 | </code> |
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88 | </blockquote> |
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89 | </body> |
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90 | </html> |
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91 | </pre></body></html> |
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