SongBean


1   // $Id: SongBean.java,v 1.1 2002/07/18 09:08:03 per_nyfelt Exp $
2   
3   package webapp;
4   
5   import org.apache.log4j.Category;
6   
7   import javax.servlet.http.*;
8   
9   import song.Song;
10  import song.SongServices;
11  
12  /**
13   * An Application object for the (persistent) song.Song data object.
14   * A song.Song is someone who is active in the organization.
15   * This Bean is does nifty web-oriented stuff like validating fields
16   * and making sure everything is kosher before creating a persistent
17   * song.
18   *
19   * @version $Revision: 1.1 $ $Date: 2002/07/18 09:08:03 $
20   * @author James Stiefel
21   */
22  
23  public class SongBean {
24  
25      //local stuff to deal with life
26      Song                m_real_song     = null;
27      String                m_message       = new String  ();
28  
29      String                m_submit_action = null;
30  
31      String                m_handle        = "-2";
32  
33      //real fields
34      String                m_title         = new String  ();
35      String                m_author        = new String  ();
36      String                m_copyright     = new String  ();
37      String                m_publisher     = new String  ();
38  
39      private static Category logger = Category.getInstance(SongBean.class.getName());
40  
41  
42      /**
43       * Sets the WebApp object. There should be a single WebApp per context.
44       * The JSP should set it in here before it expects this guy to do any
45       * important work, like talk to the database.
46       *
47       */
48  
49      public void setSubmit(String   sub) {
50          m_submit_action = sub;
51      }
52  
53      public String   getSubmit() {
54          return m_submit_action;
55      }
56  
57      /**
58       * Initialize this object (application data values only)
59       *
60       */
61  
62      public void initThis(){
63          m_real_song = null;
64  
65          m_handle        = "-2";
66  
67          //real fields
68          m_title         = new String  ();
69          m_author        = new String  ();
70          m_copyright     = new String  ();
71          m_publisher     = new String  ();
72      }
73  
74      public boolean processAddRequest(HttpServletRequest request) {
75  
76          logger.debug("processAddRequest(): action =" + m_submit_action);
77  
78          boolean created  = createIfValid();
79  
80          if (created){
81              return true;
82          } else {
83              return false;
84          }
85      }
86  
87      public boolean processUpdateRequest(HttpServletRequest request) {
88  
89          logger.debug("processUpdateRequest(): action =" + m_submit_action);
90  
91          /* Note:  this is a simple sample application.  It does not properly
92          update the song index if you update the title of the song.  The persistent
93          song.Song's title will be updated, but it will still be indexed by the old title;
94          lookups by (the new) title will fail. */
95  
96          if (isValidForUpdate()) {
97              try {
98                  thisToReal();
99                  return true;
100             } catch (Exception   e) {
101                 logger.error("processUpdateRequest() failed to update");
102             }
103         }
104         return false;
105     }
106 
107 
108     public Song   songForTitle(String   title) {
109 
110         if( title == null  || title.length() == 0){
111              logger.info("Bean songForTitle: NULL name.");
112              m_real_song = null;
113              initThis();
114              return null;
115         }
116 
117        m_real_song = SongServices.songForTitle(title);
118        if (m_real_song == null){
119            logger.warn("songForTitle: NOT retrieved.");
120            initThis();
121        }else {
122            realToThis();
123        }
124 
125         return m_real_song;
126     }
127 
128     public Song   songForHandle(String   handle) {
129 
130         if( handle == null  || handle.length() == 0){
131             logger.error("Bean songForHandle: NULL handle.");
132             m_real_song = null;
133             initThis();
134             return null;
135         }
136 
137        m_real_song = SongServices.songForHandle(handle);
138        if (m_real_song == null){
139            logger.warn("songForHandle: NOT retrieved.");
140            initThis();
141        }else {
142            realToThis();
143        }
144 
145         return m_real_song;
146     }
147 
148     /**
149      *  If the data is deemed valid, then a new persistent song.Song object
150      *  is created, and its values set according to the data.
151      *
152      * @return true if successful
153      */
154     public boolean createIfValid(){
155         logger.debug("Bean creation:  entering creation function.");
156 
157         if (this.isValidForAdd()){
158             logger.debug("Bean creation:  valid song.");
159             try {
160 
161                 m_real_song = SongServices.createSong(m_title);
162 
163                 if (m_real_song == null){
164                     logger.warn("Bean creation:  song creation failed.");
165                     return false;
166                 } else {
167                     logger.debug("Bean creation:  song created successfully.");
168                 }
169             } catch (Exception   e){
170                 logger.error("Bean creation: Ozone create Object failed. song.Song NOT created.", e);
171                 return false;
172             }
173             thisToReal();
174 
175             return true;
176         }
177         return false;
178     }
179 
180     /**
181      * Moves data values from this transient store to the associated
182      * persisteant Memeber
183      *
184      */
185     private void thisToReal(){
186         m_real_song.setTitle (this.getTitle());
187         m_real_song.setAuthor (this.getAuthor());
188         m_real_song.setCopyright (this.getCopyright());
189         m_real_song.setPublisher (this.getPublisher());
190     }
191 
192 
193     /**
194      * Moves data values from the associated persistent song
195      * to this temporary song.
196      *
197      */
198     private void realToThis(){
199 
200         this.setTitle           (m_real_song.getTitle());
201         this.setAuthor          (m_real_song.getAuthor());
202         this.setCopyright    (m_real_song.getCopyright());
203         this.setPublisher       (m_real_song.getPublisher());
204     }
205 
206 
207     /**
208      * Retrieves the object's unique (database) Handle
209      *
210      * @return the object handle
211      */
212     public String   handle(){
213 
214         if(m_real_song != null){
215             return m_real_song.handle();
216         }
217 
218         //or local string copy...hopefully a valid handle
219         return m_handle;
220     }
221     /**
222      * Retrieves the object's unique (database) objectID
223      * This is primarly to satisfy the interface OzoneRemote.
224      * We don't really use it, but we want to implement the same interface to keep us honest.
225      *
226      * @return the object handle
227      */
228 
229     /**
230      *  Sets Title. Username is the name used to sign on to the site.
231      *  Username may differ from the song.Song's actual name, and must be
232      *  unique systemwide.
233      */
234     public void     setTitle (String   title){
235         m_title = title.trim();
236     }
237 
238     /**
239      *  Retrieves Title, a song.Song's unique name.
240      */
241     public String     getTitle (){
242         return  m_title;
243     }
244 
245     /**
246      *  Sets Author.
247      *
248      */
249     public void     setAuthor (String   author){
250        m_author = author.trim();
251     }
252 
253     /**
254      *  Retrieves Author
255      */
256     public String     getAuthor (){
257         return  m_author;
258     }
259 
260     /**
261      *  Sets Copyright
262      */
263     public void     setCopyright (String   copyright){
264        m_copyright = copyright.trim();
265     }
266 
267     /**
268      *  Retrieves Copyright
269      */
270     public String     getCopyright (){
271         return  m_copyright;
272     }
273 
274     /**
275      *  Sets Publisher
276      */
277     public void     setPublisher (String   publisher){
278         m_publisher  = publisher.trim();
279     }
280 
281     /**
282      *  Retrieves first name
283      */
284     public String     getPublisher (){
285         return  m_publisher;
286     }
287 
288 
289     //Validation routines
290     /**
291      *  Tests fields to see if they are filled in.
292      *  Validations includes title uniqueness test against dB
293      */
294     public boolean isValidForAdd(){
295         m_message = new String  ();
296 
297         boolean success = true;
298 
299         if (SongServices.getAllSongs().findSong(m_title) != null){
300             m_message += "song.Song title already exists in database.<br/>";
301             success = false;
302         }
303         if (! validateTitle())
304             success = false;
305         if (!validateAuthor())
306             success = false;
307         if (!validateCopyright())
308             success = false;
309         if (!validatePublisher())
310             success = false;
311 
312         return success;
313 
314     }
315 
316     /**
317      *  Tests fields to see if they are filled in.
318      *  No username validation is performed since we won't be updating it.
319      *
320      */
321     public boolean isValidForUpdate(){
322         m_message = new String  ();
323 
324         boolean success = true;
325 
326         if ( m_title.length() == 0 ){
327             m_message += "Title cannot be blank.<br/>";
328             success = false;
329         }
330         //if renaming, make sure new name is not taken
331         if ( !m_title.toUpperCase().equals(m_real_song.getTitle().toUpperCase()) ){
332             if (SongServices.getAllSongs().findSong(m_title) != null){
333                 m_message += "New title already exists in database.<br/>";
334                 success = false;
335             }
336         }
337 
338         if (!validateAuthor())
339             success = false;
340         if (!validateCopyright())
341             success = false;
342         if (!validatePublisher())
343             success = false;
344 
345         return success;
346 
347     }
348 
349 
350     /**
351      * Gets any error messages generated by the validation.
352      */
353     public String    getMessage() {
354         return m_message;
355     }
356 
357     public boolean              validateTitle()    {
358         if (m_title == null){
359             m_message += "Title null.<br/>";
360             return false;
361         } else if (m_title.length() == 0){
362             m_message += "Title empty.<br/>";
363             return false;
364         }
365 
366         //all good
367         return true;
368     }
369 
370     public boolean              validateCopyright(){
371         if (m_copyright == null){
372             m_message += "Copyright null.<br/>";
373             return false;
374         } else if (m_copyright.length() == 0){
375             //song don't have to be copyrighted
376         }
377 
378         //all good
379         return true;
380     }
381     public boolean              validatePublisher()   {
382         if (m_publisher == null){
383             m_message += "Publisher null.<br/>";
384             return false;
385         } else if (m_publisher.length() == 0){
386             //songs don't have to be published
387         }
388 
389         //all good
390         return true;
391     }
392     public boolean              validateAuthor()    {
393         if (m_author == null){
394             m_message += "Author null.<br/>";
395             return false;
396         } else if (m_author.length() == 0){
397             //don't have to know the author
398         }
399 
400         //all good
401         return true;
402     }
403 
404 }
405
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