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Java > Open Source Codes > org > apache > taglibs > request > IsSessionValidTag


1 /*
2  * Copyright 1999,2004 The Apache Software Foundation.
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16
17 package org.apache.taglibs.request;
18
19 import java.util.*;
20 import javax.servlet.*;
21 import javax.servlet.http.*;
22 import javax.servlet.jsp.*;
23 import javax.servlet.jsp.tagext.*;
24
25 /**
26  * JSP Tag <b>issessionvalid</b>, used to determine if HttpServletRequest
27  * session is valid.
28  * <p>
29  * Includes the body of the tag if session is valid.
30  * <p>
31  * You can set the optional tag attribute <b>value</b> to <i>true</i> or
32  * <i>false</i>. The body of the tag is included if issessionvalid matches
33  * the value.
34  * <p>
35  * JSP Tag Lib Descriptor
36  * <p><pre>
37  * &lt;name&gt;issessionvalid&lt;/name&gt;
38  * &lt;tagclass&gt;org.apache.taglibs.request.IsSessionValidTag&lt;/tagclass&gt;
39  * &lt;bodycontent&gt;JSP&lt;/bodycontent&gt;
40  * &lt;info&gt;Test whether the HTTP session is valid.&lt;/info&gt;
41  * &lt;attribute&gt;
42  * &lt;name&gt;value&lt;/name&gt;
43  * &lt;required&gt;false&lt;/required&gt;
44  * &lt;rtexprvalue&gt;false&lt;/rtexprvalue&gt;
45  * &lt;/attribute&gt;
46  * </pre>
47  *
48  * @author Glenn Nielsen
49  */
50
51 public class IsSessionValidTag extends TagSupport
52 {
53     private boolean value = true;
54
55     /**
56      * Determines whether session is valid.
57      *
58      * @return SKIP_BODY if issessionvalid doesn't match value, EVAL_BODY_include if issessionvalid matches value
59      */
60     public final int doStartTag() throws JspException
61     {
62     boolean result = ((HttpServletRequest)pageContext.getRequest()).isRequestedSessionIdValid();
63
64     if( value == result )
65         return EVAL_BODY_INCLUDE;
66
67     return SKIP_BODY;
68     }
69
70     /**
71      * Set the optional tag attribute <b>value</b> to true or false.
72      *
73      * @param boolean true or false
74      */
75     public final void setValue(boolean value)
76     {
77     this.value = value;
78     }
79
80 }
81
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