View Javadoc

1   /*
2    * Copyright 1999-2002,2004 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  
18  package org.apache.struts.webapp.example;
19  
20  
21  import java.lang.reflect.InvocationTargetException;
22  
23  import javax.servlet.ServletException;
24  import javax.servlet.http.HttpServletRequest;
25  import javax.servlet.http.HttpServletResponse;
26  import javax.servlet.http.HttpSession;
27  
28  import org.apache.commons.beanutils.PropertyUtils;
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.ActionForm;
33  import org.apache.struts.action.ActionForward;
34  import org.apache.struts.action.ActionMapping;
35  import org.apache.struts.util.MessageResources;
36  
37  
38  /***
39   * Implementation of <strong>Action</strong> that validates and creates or
40   * updates the mail subscription entered by the user.
41   *
42   * @author Craig R. McClanahan
43   * @version $Rev: 421493 $ $Date: 2006-07-12 20:52:31 -0700 (Wed, 12 Jul 2006) $
44   */
45  
46  public final class SaveSubscriptionAction extends Action {
47  
48  
49      // ----------------------------------------------------- Instance Variables
50  
51  
52      /***
53       * The <code>Log</code> instance for this application.
54       */
55      private Log log =
56          LogFactory.getLog("org.apache.struts.webapp.Example");
57  
58  
59      // --------------------------------------------------------- Public Methods
60  
61  
62      /***
63       * Process the specified HTTP request, and create the corresponding HTTP
64       * response (or forward to another web component that will create it).
65       * Return an <code>ActionForward</code> instance describing where and how
66       * control should be forwarded, or <code>null</code> if the response has
67       * already been completed.
68       *
69       * @param mapping The ActionMapping used to select this instance
70       * @param form The optional ActionForm bean for this request (if any)
71       * @param request The HTTP request we are processing
72       * @param response The HTTP response we are creating
73       *
74       * @exception Exception if the application business logic throws
75       *  an exception
76       */
77      public ActionForward execute(ActionMapping mapping,
78  				 ActionForm form,
79  				 HttpServletRequest request,
80  				 HttpServletResponse response)
81  	throws Exception {
82  
83  	// Extract attributes and parameters we will need
84  	MessageResources messages = getResources(request);
85  	HttpSession session = request.getSession();
86  	SubscriptionForm subform = (SubscriptionForm) form;
87  	String action = subform.getAction();
88  	if (action == null) {
89  	    action = "?";
90          }
91          if (log.isDebugEnabled()) {
92              log.debug("SaveSubscriptionAction:  Processing " + action +
93                        " action");
94          }
95  
96  	// Is there a currently logged on user?
97  	User user = (User) session.getAttribute(Constants.USER_KEY);
98  	if (user == null) {
99              if (log.isTraceEnabled()) {
100                 log.trace(" User is not logged on in session "
101                           + session.getId());
102             }
103 	    return (mapping.findForward("logon"));
104         }
105 
106 	// Was this transaction cancelled?
107 	if (isCancelled(request)) {
108             if (log.isTraceEnabled()) {
109                 log.trace(" Transaction '" + action +
110                           "' was cancelled");
111             }
112             session.removeAttribute(Constants.SUBSCRIPTION_KEY);
113 	    return (mapping.findForward("success"));
114 	}
115 
116 	// Is there a related Subscription object?
117 	Subscription subscription =
118 	  (Subscription) session.getAttribute(Constants.SUBSCRIPTION_KEY);
119         if ("Create".equals(action)) {
120             if (log.isTraceEnabled()) {
121                 log.trace(" Creating subscription for mail server '" +
122                           subform.getHost() + "'");
123             }
124             subscription =
125                 user.createSubscription(subform.getHost());
126         }
127 	if (subscription == null) {
128             if (log.isTraceEnabled()) {
129                 log.trace(" Missing subscription for user '" +
130                           user.getUsername() + "'");
131             }
132 	    response.sendError(HttpServletResponse.SC_BAD_REQUEST,
133 	                       messages.getMessage("error.noSubscription"));
134 	    return (null);
135 	}
136 
137 	// Was this transaction a Delete?
138 	if (action.equals("Delete")) {
139             if (log.isTraceEnabled()) {
140                 log.trace(" Deleting mail server '" +
141                           subscription.getHost() + "' for user '" +
142                           user.getUsername() + "'");
143             }
144             user.removeSubscription(subscription);
145 	    session.removeAttribute(Constants.SUBSCRIPTION_KEY);
146             try {
147                 UserDatabase database = (UserDatabase)
148                     servlet.getServletContext().
149                     getAttribute(Constants.DATABASE_KEY);
150                 database.save();
151             } catch (Exception e) {
152                 log.error("Database save", e);
153             }
154 	    return (mapping.findForward("success"));
155 	}
156 
157 	// All required validations were done by the form itself
158 
159 	// Update the persistent subscription information
160         if (log.isTraceEnabled()) {
161             log.trace(" Populating database from form bean");
162         }
163         try {
164             PropertyUtils.copyProperties(subscription, subform);
165         } catch (InvocationTargetException e) {
166             Throwable t = e.getTargetException();
167             if (t == null)
168                 t = e;
169             log.error("Subscription.populate", t);
170             throw new ServletException("Subscription.populate", t);
171         } catch (Throwable t) {
172             log.error("Subscription.populate", t);
173             throw new ServletException("Subscription.populate", t);
174         }
175 
176         try {
177             UserDatabase database = (UserDatabase)
178                 servlet.getServletContext().
179                 getAttribute(Constants.DATABASE_KEY);
180             database.save();
181         } catch (Exception e) {
182             log.error("Database save", e);
183         }
184 
185 	// Remove the obsolete form bean and current subscription
186 	if (mapping.getAttribute() != null) {
187             if ("request".equals(mapping.getScope()))
188                 request.removeAttribute(mapping.getAttribute());
189             else
190                 session.removeAttribute(mapping.getAttribute());
191         }
192 	session.removeAttribute(Constants.SUBSCRIPTION_KEY);
193 
194 	// Forward control to the specified success URI
195         if (log.isTraceEnabled()) {
196             log.trace(" Forwarding to success page");
197         }
198 	return (mapping.findForward("success"));
199 
200     }
201 
202 
203 }