BasePO


1   /*
2    * Enhydra Java Application Server Project
3    *
4    * The contents of this file are subject to the Enhydra Public License
5    * Version 1.1 (the "License"); you may not use this file except in
6    * compliance with the License. You may obtain a copy of the License on
7    * the Enhydra web site ( http://www.enhydra.org/ ).
8    *
9    * Software distributed under the License is distributed on an "AS IS"
10   * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
11   * the License for the specific terms governing rights and limitations
12   * under the License.
13   *
14   * The Initial Developer of the Enhydra Application Server is Lutris
15   * Technologies, Inc. The Enhydra Application Server and portions created
16   * by Lutris Technologies, Inc. are Copyright Lutris Technologies, Inc.
17   * All Rights Reserved.
18   *
19   * Contributor(s):
20   *
21   * $Id: BasePO.java,v 1.2 2004/09/20 13:27:59 zoran Exp $
22   */
23  
24  package org.enhydra.pim.presentation;
25  
26  import java.lang.reflect.InvocationTargetException  ;
27  import java.lang.reflect.Method  ;
28  import java.sql.SQLException  ;
29  
30  import org.enhydra.pim.Enhydrapim;
31  import org.enhydra.pim.business.TransactionContextI;
32  import org.enhydra.pim.business.api.CommonConstants;
33  import org.enhydra.pim.business.api.OwnerI;
34  import org.enhydra.pim.exception.EnhydraPimException;
35  import org.enhydra.pim.presentation.enhydrapim.ErrorHTML;
36  import org.enhydra.pim.presentation.enhydrapim.IndexHTML;
37  import org.enhydra.pim.spec.TransactionContextFactory;
38  import org.enhydra.xml.xmlc.XMLObject;
39  import org.w3c.dom.Element  ;
40  
41  import com.lutris.appserver.server.Enhydra;
42  import com.lutris.appserver.server.httpPresentation.ClientPageRedirectException;
43  import com.lutris.appserver.server.httpPresentation.HttpPresentation;
44  import com.lutris.appserver.server.httpPresentation.HttpPresentationComms;
45  import com.lutris.appserver.server.httpPresentation.HttpPresentationException;
46  import com.lutris.logging.Logger;
47  import com.lutris.util.KeywordValueException;
48  
49  /**
50   * This is the parent Presentaion object. All presentation objects should extend
51   * this class.
52   * 
53   * The run method looks for an event parameter and then calls handle
54   * <EventName>. If the "event" Parameter is not defined then the handleDefault()
55   * method is called in your child class.
56   */
57  
58  public abstract class BasePO implements HttpPresentation {
59  
60      public static final String    LOGIN_PAGE  = "Index.po";
61      public static final String    ERROR_PAGE  = "Error.po";
62  
63      private static String   EVENT = "event";
64  
65      private static String   STANDARD_METHOD_PREFIX = "handle";
66  
67      /**
68       * This is the procedure that is called if there is no "event" HTTP
69       * parameter found. It must be overriden by the subclass to do default
70       * processing or error checking/handling.
71       * 
72       * @return String The String representation of the HTML or (other format) of
73       *         the document to be displayed. This method would need to be
74       *         changed if you wanted to return binary data as well. It returns a
75       *         String for simplicity right now.
76       */
77      public abstract XMLObject handleDefault() throws HttpPresentationException;
78  
79      /**
80       * This method should be implemented in the subclass so that it returns true
81       * if this particular request requires the user to be logged in, otherwise
82       * false.
83       */
84      protected abstract boolean loggedInUserRequired();
85  
86      /**
87       * Saved input and output context, and session data
88       */
89      protected HttpPresentationComms myComms = null;
90  
91      /**
92       * 
93       * @uml.property name="mySessionData"
94       * @uml.associationEnd multiplicity="(0 1)"
95       */
96      protected EnhydraPimSessionData mySessionData = null;
97  
98      /**
99       * Reference to the person logged in to the session
100      * 
101      * @uml.property name="myPerson"
102      * @uml.associationEnd multiplicity="(0 1)"
103      */
104     protected OwnerI myPerson = null;
105 
106     /**
107      * Gets HttpPresentation object
108      * 
109      * @return The saved comms objects to whichever subclass needs it
110      */
111     public HttpPresentationComms getComms() {
112         return this.myComms;
113     }
114 
115     /**
116      * Gets the session data
117      * 
118      * @return session data
119      */
120     public EnhydraPimSessionData getSessionData() {
121         return this.mySessionData;
122     }
123 
124     /**
125      * Sets the user into the session
126      * 
127      * @param thePerson
128      *            the person to be set in the session
129      * @exception EnhydraPimPresentationException
130      */
131     public void setUser(OwnerI thePerson)
132             throws EnhydraPimPresentationException {
133         this.getSessionData().setUser(thePerson);
134     }
135 
136     /**
137      * Gets the user from the session
138      * 
139      * @return the person object in the session
140      */
141     public OwnerI getUser() {
142         return this.getSessionData().getUser();
143     }
144 
145     /**
146      * Method to remove the current user from the session
147      */
148     public void removeUserFromSession() {
149         this.getSessionData().removeUser();
150     }
151 
152     /**
153      * This implements the run method in HttpPresentation.
154      * 
155      * @param comms
156      *            HttpPresentationComms
157      * @exception Exception
158      */
159     public void run(HttpPresentationComms comms) throws Exception   {
160         // Initialize new or get the existing session data
161         initSessionData(comms);
162         
163         // Check if the user needs to be logged in for this request.
164         if (this.loggedInUserRequired()) {
165             checkForUserLogin();
166         }
167         
168         TransactionContextI transCtx= TransactionContextFactory.getTransactionContext();
169 
170         try {
171             transCtx.beginContext(CommonConstants.productionDatabaseName);
172             handleEvent(comms);
173         }catch(Exception   e){
174             transCtx.rollbackContext();
175             throw new EnhydraPimException("Unhandled Application Error");
176         }finally {
177             try {
178                 transCtx.commitContext();
179             } catch (SQLException   e){
180                 throw new EnhydraPimException("Unhandled Application Error");
181             }
182         }
183         
184     }
185 
186     /**
187      * Method to get or create the AgSessionData object from the user session
188      * This object is saved in the EbrokerPresentation object
189      * 
190      * @param comms
191      *            HttpPresentationComms
192      * @exception Exception
193      */
194     protected void initSessionData(HttpPresentationComms comms)
195             throws EnhydraPimPresentationException {
196         this.myComms = comms;
197 
198         try {
199             Object   obj = comms.sessionData.get(EnhydraPimSessionData.SESSION_KEY);
200             // If we found the session data, save it in a private data member
201             if (null != obj) {
202                 this.mySessionData = (EnhydraPimSessionData) obj;
203             } else {
204                 // If no session data was found, create a new session data
205                 // instance
206                 this.mySessionData = new EnhydraPimSessionData();
207                 comms.sessionData.set(EnhydraPimSessionData.SESSION_KEY,
208                         this.mySessionData);
209             }
210         } catch (KeywordValueException ex) {
211             writeDebugMsg("Problem getting session data from session: "
212                     + ex.getMessage());
213         }
214     }
215 
216     
217     /**
218      * Checks the session data for a User, if not there then redirects to the
219      * login page
220      */
221     protected void checkForUserLogin() throws ClientPageRedirectException,
222             EnhydraPimPresentationException {
223 
224         try {
225             OwnerI user = getUser();
226 
227             if (null == user) {
228 //                String uri = myComms.request.getRequestURI();
229 //                boolean is = uri.startsWith("/discRack_pres");
230 //                if (!is) {
231 
232                     writeDebugMsg("USER NOT FOUND IN SESSION");
233                     //send to LoginPage if a logged in user is required.
234                     String   requestedPO = myComms.request.getRequestURI();
235                     this.writeDebugMsg("PO: " + requestedPO);
236                     // Call the subclass's implemented method
237                     writeDebugMsg("REDIRECTING TO LOGIN PAGE");
238                     throw new ClientPageRedirectException(LOGIN_PAGE);
239 //                }
240             } else {
241                 writeDebugMsg("USER ALREADY LOGGED IN WITH A SESSION");
242             }
243 
244         } catch (Exception   ex) {
245             throw new EnhydraPimPresentationException(
246                     "Trouble checking for user login status", ex);
247         }
248     }
249 
250     
251     /**
252      * Method to call the proper method for the incoming event
253      * 
254      * @param comms
255      *            HttpPresentationComms
256      * @exception Exception
257      */
258     public void handleEvent(HttpPresentationComms comms) throws Exception   {
259         String   event = comms.request.getParameter(EVENT);
260 
261         XMLObject returnHTML = null;
262         
263         try {
264             // Handle the incoming event request
265             if (event == null || event.length() == 0 || event.equalsIgnoreCase("none") || event.equalsIgnoreCase("Default")) {
266                 returnHTML = handleDefault();
267             } else {
268                 returnHTML = getPageContentForEvent(event);
269             }
270             //comms.response.setEncoding("UTF8");
271             if(getUser()!=null && getUser().getUsername()!=null) {
272                 Element   htm =returnHTML.getElementById("LogUserName");
273                 htm.getFirstChild().setNodeValue("<"+getUser().getUsername()+">");
274             }
275         } catch (Exception   e) {
276             e.printStackTrace();
277             returnHTML = showErrorPage("Presentation Error:"+e.getMessage());
278         }
279         comms.response.writeDOM(returnHTML);
280     }
281 
282     /**
283      * If an event parameter is defined then this invokes the method that
284      * handles that event.
285      * 
286      * @param event
287      *            the incoming event name
288      * @exception Exception
289      */
290     public XMLObject getPageContentForEvent(String   event) throws Exception   {
291 
292         try {
293             Method   method = this.getClass().getMethod(toMethodName(event), null);
294             XMLObject thePage = (XMLObject) method.invoke(this, null);
295             
296             return thePage;
297         } catch (InvocationTargetException   ex) {
298             // Rethrow the originating exception if as it should be propagated
299             // as is
300             // It could be a page redirect exception, etc.
301             if (ex.getTargetException() instanceof Exception  ) {
302                 throw (Exception  ) ex.getTargetException();
303             } else if (ex.getTargetException() instanceof Error  ) {
304                 throw (Error  ) ex.getTargetException();
305             } else {
306                 throw ex;
307             }
308         } catch (NoSuchMethodException   ex) {
309             //The method to handle the event does not exist.
310             throw new EnhydraPimPresentationException(
311                     "NO EVENT HANDLER FOUND FOR EVENT: " + event, ex);
312         } catch (IllegalAccessException   ex) {
313             //The method to handle the event does not exist.
314             throw new EnhydraPimPresentationException(
315                     "ILLEGAL ACCESS TO EVENT HANDLER (is it public?): " + event,
316                     ex);
317         }
318     }
319 
320     /**
321      * This sets the first letter of the event parameter value in order to
322      * adhere to Java method naming conventions.
323      * 
324      * @param event
325      *            the incoming name of the event
326      * @return String the properly capitalized name
327      */
328     private String   toMethodName(String   event) {
329         StringBuffer   methodName = new StringBuffer  (STANDARD_METHOD_PREFIX);
330         methodName.append(Character.toUpperCase(event.charAt(0)));
331 
332         if (event.length() > 1) {
333             methodName.append(event.substring(1));
334         }
335 
336         return methodName.toString();
337     }
338 
339     /**
340      * Returns the application object associated with the current request.
341      * 
342      * @return the application object.
343      */
344     public Enhydrapim getApplication() {
345         return (Enhydrapim) Enhydra.getApplication();
346     }
347 
348     /**
349      * Method to write a debugging message to the debug log channel when the
350      * DEBUG flag is turned on
351      * 
352      * @param msg
353      *            The message to write to the DEBUG log channel
354      */
355     public static void writeDebugMsg(String   msg) {
356         Enhydra.getLogChannel().write(Logger.DEBUG, msg);
357     }
358     
359     
360     
361     /**
362      * Display Error.html page
363      * 
364      * @return html document
365      * @throws ClientPageRedirectException
366      * @throws HttpPresentationException
367      */
368     public void goToErrorPage(String   errorText) throws ClientPageRedirectException, HttpPresentationException{
369         if(errorText!=null) {
370             this.getSessionData().setUserMessage(errorText);
371         }
372         throw new ClientPageRedirectException(ERROR_PAGE);
373     }
374     
375     
376     /**
377      * Display Error.html page
378      * 
379      * @return html document
380      * @throws ClientPageRedirectException
381      * @throws HttpPresentationException
382      */
383     public XMLObject showErrorPage(String   errorText) throws ClientPageRedirectException, HttpPresentationException{
384         ErrorHTML errorPage = (ErrorHTML) myComms.xmlcFactory.create(ErrorHTML.class);
385         if(errorText!=null) {
386             errorPage.setTextErrorText(errorText);
387         }else {
388             errorPage.setTextErrorText("Unhandled presentation Error");
389         }
390         return errorPage;
391     }
392     
393 
394     
395     /**
396      * Display Index.html page
397      * 
398      * @return html document
399      */
400     public XMLObject showIndexPage() {
401         return (IndexHTML) myComms.xmlcFactory.create(IndexHTML.class);
402     }
403     
404 }
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