SaveSupport


1   /*
2    * The contents of this file are subject to the terms of the Common Development
3    * and Distribution License (the License). You may not use this file except in
4    * compliance with the License.
5    *
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11   * If applicable, add the following below the CDDL Header, with the fields
12   * enclosed by brackets [] replaced by your own identifying information:
13   * "Portions Copyrighted [year] [name of copyright owner]"
14   *
15   * The Original Software is NetBeans. The Initial Developer of the Original
16   * Software is Sun Microsystems, Inc. Portions Copyright 1997-2006 Sun
17   * Microsystems, Inc. All Rights Reserved.
18   */
19  
20  package org.netbeans.modules.settings;
21  
22  import java.beans.*;
23  import java.io.IOException  ;
24  import java.util.logging.Level  ;
25  import java.util.logging.Logger  ;
26  
27  import org.openide.cookies.SaveCookie;
28  import org.openide.filesystems.FileSystem;
29  import org.openide.filesystems.FileObject;
30  
31  import org.netbeans.spi.settings.Convertor;
32  import org.netbeans.spi.settings.Saver;
33  import org.openide.util.Exceptions;
34  
35  /** Support handles automatic storing/upgrading; notifies about changes in file.
36   *
37   * @author  Jan Pokorsky
38   */
39  final class SaveSupport {
40      /** property means setting is changed and should be changed */
41      public final static String   PROP_SAVE = "savecookie"; //NOI18N
42      /** property means setting file content is changed */
43      public final static String   PROP_FILE_CHANGED = "fileChanged"; //NOI18N
44      /** data object name cached in the attribute to prevent instance creation when
45       * its node is displayed.
46       * @see org.openide.loaders.InstanceDataObject#EA_NAME
47       */
48      static final String   EA_NAME = "name"; // NOI18N
49      
50      /** support for PropertyChangeListeners */
51      private PropertyChangeSupport changeSupport;
52      
53      /** convertor for possible format upgrade */
54      private Convertor convertor;
55      /** SaveCookie implementation */
56      private final SaveCookieImpl instToSave = new SaveCookieImpl();
57      /** setting is already changed */
58      private boolean isChanged = false;
59      /** .settings file */
60      private final FileObject file;
61      /** reference to setting object */
62      private final java.lang.ref.SoftReference  <Object  > instance;
63      private final InstanceProvider ip;
64      /** remember whether the DataObject is a template or not; calling isTemplate() is slow  */
65      private Boolean   knownToBeTemplate = null;
66      
67      /** Creates a new instance of SaveSupport
68       * @param ip instance provider
69       * @param inst setting object
70       */
71      public SaveSupport(InstanceProvider ip, Object   inst) {
72          this.ip = ip;
73          this.instance = new java.lang.ref.SoftReference  <Object  >(inst);
74          this.file = ip.getFile();
75      }
76      
77      /** get convertor for possible upgrade; can be null */
78      private Convertor getConvertor() {
79          return convertor;
80      }
81      
82      /** try to find out convertor for possible upgrade and cache it; can be null */
83      private Convertor initConvertor() {
84          Object   inst = instance.get();
85          if (inst == null) {
86              throw new IllegalStateException  ("setting object cannot be null: " + ip);// NOI18N
87          }
88          
89          try {
90              FileObject newProviderFO = Env.findProvider(inst.getClass());
91              if (newProviderFO != null) {
92                  if (getPublicID(newProviderFO).equals(getPublicID(ip.getProvider()))) {
93                      // nothing to upgrade
94                      convertor = ip.getConvertor();
95                      return convertor;
96                  }
97                  Object   attrb = newProviderFO.getAttribute(Env.EA_CONVERTOR);
98                  if (attrb == null || !(attrb instanceof Convertor)) {
99                      throw new IOException  ("cannot create convertor: " + attrb + ", provider: " + newProviderFO); //NOI18N
100                 } else {
101                     convertor = (Convertor) attrb;
102                     return convertor;
103                 }
104             }
105             convertor = ip.getConvertor();
106         } catch (IOException   ex) {
107             Logger.getLogger(SaveSupport.class.getName()).log(Level.WARNING, null, ex);
108         }
109         return convertor;
110     }
111     
112     /** get publicid of the file fo */
113     private String   getPublicID(FileObject fo) throws IOException   {
114         FileObject foEntity = Env.findEntityRegistration(fo);
115         if (foEntity == null) foEntity = fo;
116         Object   publicId = foEntity.getAttribute(Env.EA_PUBLICID);
117         if (publicId == null || !(publicId instanceof String  )) {
118             throw new IOException  ("missing or invalid attribute: " + //NOI18N
119                 Env.EA_PUBLICID + ", provider: " + foEntity); //NOI18N
120         }
121         return (String  ) publicId;
122     }
123     
124     /** return SaveCookie impl */
125     public final SaveCookie getSaveCookie () {
126             return instToSave;
127     }
128     
129     /** is setting object changed? */
130     public final boolean isChanged() {
131         return isChanged;
132     }
133     
134     /** Registers PropertyChangeListener to receive events; initialize
135      * listening to events comming from the setting object and file object.
136      * @param listener The listener to register.
137      */
138     public synchronized void addPropertyChangeListener(PropertyChangeListener listener) {
139         if (changeSupport == null) {
140             changeSupport = new PropertyChangeSupport(this);
141             Object   inst = instance.get();
142             if (inst == null) return;
143             Convertor conv = initConvertor();
144             if (conv != null) {
145                 conv.registerSaver(inst, instToSave);
146             }
147         }
148         changeSupport.addPropertyChangeListener(listener);
149     }
150     
151     /** Removes PropertyChangeListener from the list of listeners.
152      * @param listener The listener to remove.
153      */
154     public synchronized void removePropertyChangeListener(PropertyChangeListener listener) {
155         if (changeSupport != null) {
156             changeSupport.removePropertyChangeListener(listener);
157             Object   inst = instance.get();
158             if (inst == null) return;
159             Convertor conv = getConvertor();
160             if (conv != null) {
161                 conv.unregisterSaver(inst, instToSave);
162             }
163         }
164     }
165     
166     /** Notifies all registered listeners about the event.
167      * @param event The event to be fired
168      * @see #PROP_FILE_CHANGED
169      * @see #PROP_SAVE
170      */
171     private void firePropertyChange(String   name) {
172         if (changeSupport != null)
173             changeSupport.firePropertyChange(name, null, null);
174     }
175     
176     /** called by ScheduledRequest in order to perform the request */
177     public void writeDown() throws IOException   {
178         instToSave.writeDown();
179     }
180     
181     /** Support for storing instances allowing identify the origin of file events 
182      * fired as a consequence of this storing.
183      */
184     private class SaveCookieImpl implements FileSystem.AtomicAction, SaveCookie, Saver {
185     
186         private java.io.ByteArrayOutputStream   buf;
187         
188         private SaveCookieImpl() {
189         }
190         
191         /** store buffer to the file. */
192         public void run () throws IOException   {
193             if (!ip.getDataObject().isValid()) {
194                 //invalid data object cannot be used for storing
195                 Logger.getAnonymousLogger().fine("invalid data object cannot be used for storing " + ip.getDataObject()); // NOI18N
196                 return;
197             }
198             org.openide.filesystems.FileLock lock = null;
199             java.io.OutputStream   los;
200             synchronized (ip.READWRITE_LOCK) {
201 //                if (err.isLoggable(ErrorManager.INFORMATIONAL)) {
202 //                    err.log("saving " + dobj); // NOI18N
203 //                }
204                 lock = ip.getScheduledRequest().getFileLock();
205                 if (lock == null) return;
206                 los = file.getOutputStream(lock);
207 
208                 java.io.OutputStream   os = new java.io.BufferedOutputStream  (los, 1024);
209                 try {
210                     buf.writeTo(os);
211 //                        if (err.isLoggable(ErrorManager.INFORMATIONAL)) {
212 //                            dobj.err.log("saved " + dobj); // NOI18N
213 //                        }
214                 } finally {
215                     os.close();
216                 }
217             }
218         } 
219         
220         /** Implementation of SaveCookie. */
221         public void save() throws IOException   {
222             if (!isChanged) return;
223             ip.getScheduledRequest().runAndWait();
224         }
225         
226         private void writeDown() throws IOException   {
227             Object   inst = instance.get();
228             if (inst == null) return ;
229             Convertor conv = getConvertor();
230             if (conv == null) return ;
231             java.io.ByteArrayOutputStream   b = new java.io.ByteArrayOutputStream  (1024);
232             java.io.Writer   w = ContextProvider.createWriterContextProvider(
233                 new java.io.OutputStreamWriter  (b, "UTF-8"), // NOI18N
234                 SaveSupport.this.file
235             );
236             isChanged = false;
237             try {
238                 conv.write(w, inst);
239             } finally {
240                 w.close();
241             }
242             
243             buf = b;
244             file.getFileSystem().runAtomicAction(this);
245             buf = null;
246             synchronizeName(inst);
247             if (!isChanged) firePropertyChange(PROP_SAVE);
248         }
249         
250         public void markDirty() {
251             if (isChanged || !ip.getDataObject().isValid()) return;
252             if (knownToBeTemplate == null) knownToBeTemplate = ip.getDataObject().isTemplate() ? Boolean.TRUE : Boolean.FALSE;
253             if (knownToBeTemplate.booleanValue()) return;
254             isChanged = true;
255             firePropertyChange(PROP_SAVE);
256         }
257         
258         public void requestSave() throws java.io.IOException   {
259             if (isChanged || !ip.getDataObject().isValid()) return;
260             if (knownToBeTemplate == null) knownToBeTemplate = ip.getDataObject().isTemplate() ? Boolean.TRUE : Boolean.FALSE;
261             if (knownToBeTemplate.booleanValue()) return;
262             isChanged = true;
263             firePropertyChange(PROP_SAVE);
264             ip.getScheduledRequest().schedule(instance.get());
265         }
266         
267         /** try to synchronize file name with instance name */
268         private void synchronizeName(Object   inst) {
269             java.lang.reflect.Method   getter;
270             try {
271                 try {
272                     getter = inst.getClass().getMethod("getDisplayName"); // NOI18N
273                 } catch (NoSuchMethodException   me) {
274                     getter = inst.getClass().getMethod("getName"); // NOI18N
275                 }
276             } catch (Exception   ex) { // do nothing
277                 return;
278             }
279             if (!getter.isAccessible()) return;
280             
281             try {
282                 String   name = (String  ) getter.invoke(inst);
283                 String   oldName = ip.getDataObject().getName();
284                 if (!name.equals(oldName)) {
285                     file.setAttribute(EA_NAME, name);
286                 } else if (file.getAttribute(EA_NAME) == null) {
287                     file.setAttribute(EA_NAME, name);
288                 }
289             } catch (Exception   ex) {
290                 Exceptions.attachLocalizedMessage(ex, file.toString());
291             Logger.getLogger(SaveSupport.class.getName()).log(Level.WARNING, null, ex);
292             }
293         }
294         
295     }
296     
297 }
298
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