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1   /*
2    * $Id: LogonAction.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.HttpServletRequest;
27  import javax.servlet.http.HttpSession;
28  import javax.servlet.http.HttpServletResponse;
29  import org.apache.commons.logging.Log;
30  import org.apache.commons.logging.LogFactory;
31  import org.apache.struts.action.Action;
32  import org.apache.struts.action.ActionMessage;
33  import org.apache.struts.action.ActionMessages;
34  import org.apache.struts.action.ActionForm;
35  import org.apache.struts.action.ActionForward;
36  import org.apache.struts.action.ActionMapping;
37  
38  import org.apache.struts.util.ModuleException;
39  import org.apache.commons.beanutils.PropertyUtils;
40  
41  
42  /**
43   * Implementation of <strong>Action</strong> that validates a user logon.
44   *
45   * @author Craig R. McClanahan
46   * @version $Rev: 471754 $ $Date: 2006-11-06 08:55:09 -0600 (Mon, 06 Nov 2006) $
47   */
48  
49  public final class LogonAction extends Action {
50  
51  
52      // ----------------------------------------------------- Instance Variables
53  
54  
55      /**
56       * The <code>Log</code> instance for this application.
57       */
58      private Log log =
59          LogFactory.getLog("org.apache.struts.webapp.Example");
60  
61  
62      // --------------------------------------------------------- Public Methods
63  
64  
65      /**
66       * Process the specified HTTP request, and create the corresponding HTTP
67       * response (or forward to another web component that will create it).
68       * Return an <code>ActionForward</code> instance describing where and how
69       * control should be forwarded, or <code>null</code> if the response has
70       * already been completed.
71       *
72       * @param mapping The ActionMapping used to select this instance
73       * @param form The optional ActionForm bean for this request (if any)
74       * @param request The HTTP request we are processing
75       * @param response The HTTP response we are creating
76       *
77       * @exception Exception if business logic throws an exception
78       */
79      public ActionForward execute(ActionMapping mapping,
80                   ActionForm form,
81                   HttpServletRequest request,
82                   HttpServletResponse response)
83      throws Exception {
84  
85      // Extract attributes we will need
86      User user = null;
87  
88      // Validate the request parameters specified by the user
89      ActionMessages errors = new ActionMessages();
90      String username = (String)
91              PropertyUtils.getSimpleProperty(form, "username");
92          String password = (String)
93              PropertyUtils.getSimpleProperty(form, "password");
94      UserDatabase database = (UserDatabase)
95        servlet.getServletContext().getAttribute(Constants.DATABASE_KEY);
96      if (database == null)
97              errors.add(ActionMessages.GLOBAL_MESSAGE,
98                         new ActionMessage("error.database.missing"));
99      else {
100         user = getUser(database, username);
101         if ((user != null) && !user.getPassword().equals(password))
102         user = null;
103         if (user == null)
104                 errors.add(ActionMessages.GLOBAL_MESSAGE,
105                            new ActionMessage("error.password.mismatch"));
106     }
107 
108     // Report any errors we have discovered back to the original form
109     if (!errors.isEmpty()) {
110         saveErrors(request, errors);
111             return (mapping.getInputForward());
112     }
113 
114     // Save our logged-in user in the session
115     HttpSession session = request.getSession();
116     session.setAttribute(Constants.USER_KEY, user);
117         if (log.isDebugEnabled()) {
118             log.debug("LogonAction: User '" + user.getUsername() +
119                       "' logged on in session " + session.getId());
120         }
121 
122         // Remove the obsolete form bean
123     if (mapping.getAttribute() != null) {
124             if ("request".equals(mapping.getScope()))
125                 request.removeAttribute(mapping.getAttribute());
126             else
127                 session.removeAttribute(mapping.getAttribute());
128         }
129 
130     // Forward control to the specified success URI
131     return (mapping.findForward("success"));
132 
133     }
134 
135 
136     // ------------------------------------------------------ Protected Methods
137 
138 
139     /**
140      * Look up the user, throwing an exception to simulate business logic
141      * rule exceptions.
142      *
143      * @param database Database in which to look up the user
144      * @param username Username specified on the logon form
145      *
146      * @exception AppException if a business logic rule is violated
147      */
148     public User getUser(UserDatabase database, String username)
149         throws ModuleException {
150 
151         // Force an ArithmeticException which can be handled explicitly
152         if ("arithmetic".equals(username)) {
153             throw new ArithmeticException();
154         }
155 
156         // Force an application-specific exception which can be handled
157         if ("expired".equals(username)) {
158             throw new ExpiredPasswordException(username);
159         }
160 
161         // Look up and return the specified user
162         return (database.findUser(username));
163 
164     }
165 
166 
167 }