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1   /*
2    * $Id: CheckLogonTag.java 471754 2006-11-06 14:55:09Z husted $
3    *
4    * Licensed to the Apache Software Foundation (ASF) under one
5    * or more contributor license agreements.  See the NOTICE file
6    * distributed with this work for additional information
7    * regarding copyright ownership.  The ASF licenses this file
8    * to you under the Apache License, Version 2.0 (the
9    * "License"); you may not use this file except in compliance
10   * with the License.  You may obtain a copy of the License at
11   *
12   *  http://www.apache.org/licenses/LICENSE-2.0
13   *
14   * Unless required by applicable law or agreed to in writing,
15   * software distributed under the License is distributed on an
16   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17   * KIND, either express or implied.  See the License for the
18   * specific language governing permissions and limitations
19   * under the License.
20   */
21  
22  
23  package org.apache.struts.webapp.example;
24  
25  
26  import javax.servlet.http.HttpSession;
27  import javax.servlet.jsp.JspException;
28  import javax.servlet.jsp.tagext.TagSupport;
29  
30  
31  /**
32   * Check for a valid User logged on in the current session.  If there is no
33   * such user, forward control to the logon page.
34   *
35   * @author Craig R. McClanahan
36   * @author Marius Barduta
37   * @version $Rev: 471754 $ $Date: 2006-11-06 08:55:09 -0600 (Mon, 06 Nov 2006) $
38   */
39  
40  public final class CheckLogonTag extends TagSupport {
41  
42  
43      // --------------------------------------------------- Instance Variables
44  
45  
46      /**
47       * The key of the session-scope bean we look for.
48       */
49      private String name = Constants.USER_KEY;
50  
51  
52      /**
53       * The page to which we should forward for the user to log on.
54       */
55      private String page = "/logon.jsp";
56  
57  
58      // ----------------------------------------------------------- Properties
59  
60  
61      /**
62       * Return the bean name.
63       */
64      public String getName() {
65  
66      return (this.name);
67  
68      }
69  
70  
71      /**
72       * Set the bean name.
73       *
74       * @param name The new bean name
75       */
76      public void setName(String name) {
77  
78      this.name = name;
79  
80      }
81  
82  
83      /**
84       * Return the forward page.
85       */
86      public String getPage() {
87  
88      return (this.page);
89  
90      }
91  
92  
93      /**
94       * Set the forward page.
95       *
96       * @param page The new forward page
97       */
98      public void setPage(String page) {
99  
100     this.page = page;
101 
102     }
103 
104 
105     // ------------------------------------------------------- Public Methods
106 
107 
108     /**
109      * Defer our checking until the end of this tag is encountered.
110      *
111      * @exception JspException if a JSP exception has occurred
112      */
113     public int doStartTag() throws JspException {
114 
115     return (SKIP_BODY);
116 
117     }
118 
119 
120     /**
121      * Perform our logged-in user check by looking for the existence of
122      * a session scope bean under the specified name.  If this bean is not
123      * present, control is forwarded to the specified logon page.
124      *
125      * @exception JspException if a JSP exception has occurred
126      */
127     public int doEndTag() throws JspException {
128 
129     // Is there a valid user logged on?
130     boolean valid = false;
131     HttpSession session = pageContext.getSession();
132     if ((session != null) && (session.getAttribute(name) != null))
133         valid = true;
134 
135     // Forward control based on the results
136     if (valid)
137         return (EVAL_PAGE);
138     else {
139         try {
140         pageContext.forward(page);
141         } catch (Exception e) {
142         throw new JspException(e.toString());
143         }
144         return (SKIP_PAGE);
145     }
146 
147     }
148 
149 
150     /**
151      * Release any acquired resources.
152      */
153     public void release() {
154 
155         super.release();
156         this.name = Constants.USER_KEY;
157         this.page = "/logon.jsp";
158 
159     }
160 
161 
162 }