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Java > Open Source Codes > org > apache > taglibs > session > AttributeTag


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.session;
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>attribute</b>, used to get the value of a single
27  * HttpSession attribute named <b>name</b>.
28  * <p>
29  * JSP Tag Lib Descriptor
30  * <p><pre>
31  * &lt;name&gt;attribute&lt;/name&gt;
32  * &lt;tagclass&gt;org.apache.taglibs.session.AttributeTag&lt;/tagclass&gt;
33  * &lt;bodycontent&gt;empty&lt;/bodycontent&gt;
34  * &lt;info&gt;Used to get the value of a single session attribute.&lt;/info&gt;
35  * &lt;attribute&gt;
36  * &lt;name&gt;name&lt;/name&gt;
37  * &lt;required&gt;true&lt;/required&gt;
38  * &lt;rtexprvalue&gt;false&lt;/rtexprvalue&gt;
39  * &lt;/attribute&gt;
40  * </pre>
41  *
42  * @author Glenn Nielsen
43  */
44
45 public class AttributeTag extends TagSupport
46 {
47     // Name of session attribute
48 private String JavaDoc name = null;
49
50     /**
51      * Method called at end of Tag to output attribute value
52      *
53      * @return EVAL_PAGE
54      */
55     public final int doEndTag() throws JspException
56     {
57     // Get the session attribute with name
58 Object JavaDoc value = (Object JavaDoc)pageContext.getSession().getAttribute(name);
59     if( value == null )
60         return EVAL_PAGE;
61
62     // Output the value of the session attribute
63 try {
64         pageContext.getOut().write(value.toString());
65     } catch(Exception JavaDoc e) {
66         throw new JspException("IO Error: " + e.getMessage());
67     }
68
69     return EVAL_PAGE;
70     }
71
72     /**
73      * Set the required tag attribute <b>name</b>.
74      *
75      * @param String name of session attribute
76      */
77     public final void setName(String JavaDoc str)
78     {
79     name = str;
80     }
81 }
82
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