UniFileLoader


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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9    * When distributing Covered Code, include this CDDL Header Notice in each file
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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.openide.loaders;
21  
22  import java.io.IOException  ;
23  
24  import org.openide.*;
25  import org.openide.filesystems.*;
26  import org.openide.util.io.SafeException;
27  
28  /** Support class for loader handling one file at a time.
29   * This is used for many file types, e.g. HTML, images, etc.
30   * File extensions recognized by the loader may be set.
31  *
32  * @author Petr Hamernik, Jaroslav Tulach
33  */
34  public abstract class UniFileLoader extends MultiFileLoader {
35      /** SUID */
36      static final long serialVersionUID=-6190649471408985837L;
37  
38      /** name of property with extensions */
39      public static final String   PROP_EXTENSIONS = "extensions"; // NOI18N
40      
41      /** Constructor.
42      * @param representationClass class that is produced by this loader
43       * @deprecated Use UniFileLoader#UniFileLoader(String) instead.
44      */
45      @Deprecated  
46      protected UniFileLoader(Class  <? extends DataObject> representationClass) {
47          super (representationClass);
48      }
49  
50      /** Constructor.
51      * @param representationClassName the fully qualified name of the
52      * representation class.
53      *
54      * @since 1.10
55      */
56      protected UniFileLoader (String   representationClassName) {
57          super (representationClassName);
58      }
59  
60      /** Get the primary file.
61      * By default, only accepts files, not folders.
62      * @param fo the file to find the primary file for
63      *
64      * @return the primary file, or <code>null</code> if its extension is not {@link #getExtensions recognized}
65      */
66      protected FileObject findPrimaryFile (FileObject fo) {
67          // never recognize folders
68          if (fo.isFolder()) return null;
69          
70          return getExtensions().isRegistered(fo) ? fo : null;
71      }
72  
73      /* Creates the right data object for given primary file.
74      * It is guaranteed that the provided file is realy primary file
75      * returned from the method findPrimaryFile.
76      *
77      * @param primaryFile the primary file
78      * @return the data object for this file
79      * @exception DataObjectExistsException if the primary file already has data object
80      */
81      protected abstract MultiDataObject createMultiObject (FileObject primaryFile)
82      throws DataObjectExistsException, java.io.IOException  ;
83  
84      /* Creates the right primary entry for given primary file.
85      *
86      * @param obj requesting object
87      * @param primaryFile primary file recognized by this loader
88      * @return primary entry for that file
89      */
90      protected MultiDataObject.Entry createPrimaryEntry (MultiDataObject obj, FileObject primaryFile) {
91          return new FileEntry (obj, primaryFile);
92      }
93  
94      /** Do not create a seconday entry.
95      *
96      * @param obj ignored
97      * @param secondaryFile ignored
98      * @return never returns
99      * @exception UnsupportedOperationException because this loader supports only a primary file object
100     */
101     protected MultiDataObject.Entry createSecondaryEntry (MultiDataObject obj, FileObject secondaryFile) {
102 
103         // Debug messages for #17014. Please remove, when the bug is fixed.
104         StringBuffer   buf = new StringBuffer  ("Error in data system. Please reopen the bug #17014 with the following message: "); //NOI18N
105         buf.append("\n  DataLoader:"); //NOI18N
106         buf.append(getClass().getName());
107         buf.append("\n  DataObject:"); //NOI18N
108         buf.append(obj);
109         buf.append("\n  PrimaryEntry:"); //NOI18N
110         buf.append(obj.getPrimaryEntry());
111         buf.append("\n  PrimaryFile:"); //NOI18N
112         buf.append(obj.getPrimaryFile());
113         buf.append("\n  SecondaryFile:"); //NOI18N
114         buf.append(secondaryFile);
115         buf.append("\n");
116         
117         throw new UnsupportedOperationException   (buf.toString()); //NOI18N
118     }
119 
120     /** Called when there is a collision between a data object that 
121     * this loader tries to create and already existing one.
122     * 
123     * @param obj existing data object
124     * @param file the original file that has been recognized by this loader
125     *    as bellonging to obj data object
126     * @return null 
127     */
128     final DataObject checkCollision (DataObject obj, FileObject file) {
129         return null;
130     }
131     
132     /** Does nothing because this loader works only with objects
133     * with one file => primary file so it is not necessary to search
134     * for anything else.
135     * 
136     * @param obj the object to test
137     */
138     final void checkConsistency (MultiDataObject obj) {
139     }
140     
141     /** Does nothing because this loader works only with objects
142     * with one file => primary file so it is not necessary to search
143     * for anything else.
144     * 
145     * @param obj the object to test
146     */
147     final void checkFiles (MultiDataObject obj) {
148     }
149 
150     /** Set the extension list for this data loader.
151     * @param ext new list of extensions
152     */
153     public void setExtensions(ExtensionList ext) {
154         putProperty (PROP_EXTENSIONS, ext, true);
155     }
156 
157     /** Get the extension list for this data loader.
158     * @return list of extensions
159     */
160     public ExtensionList getExtensions() {
161         ExtensionList l = (ExtensionList)getProperty (PROP_EXTENSIONS);
162         if (l == null) {
163             l = new ExtensionList ();
164             putProperty (PROP_EXTENSIONS, l, false);
165         }
166         return l;
167     }
168 
169     /** Writes extensions to the stream.
170     * @param oo ignored
171     */
172     public void writeExternal (java.io.ObjectOutput   oo) throws IOException   {
173         super.writeExternal (oo);
174 
175         oo.writeObject (getProperty (PROP_EXTENSIONS));
176     }
177 
178     /** Reads nothing from the stream.
179     * @param oi ignored
180     */
181     public void readExternal (java.io.ObjectInput   oi)
182     throws IOException  , ClassNotFoundException   {
183         SafeException se;
184         try {
185             super.readExternal (oi);
186             se = null;
187         } catch (SafeException se2) {
188             se = se2;
189         }
190 
191         setExtensions ((ExtensionList)oi.readObject ());
192         if (se != null) throw se;
193     }
194 
195 }
196
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