1 | package org.farng.mp3; |
2 | |
3 | import org.farng.mp3.id3.ID3v2_2; |
4 | import org.farng.mp3.id3.ID3v2_3; |
5 | import org.farng.mp3.id3.ID3v2_4; |
6 | import org.farng.mp3.object.AbstractMP3Object; |
7 | |
8 | import java.io.IOException; |
9 | import java.io.RandomAccessFile; |
10 | import java.util.ArrayList; |
11 | import java.util.Iterator; |
12 | import java.util.List; |
13 | |
14 | /** |
15 | * This class is contained in the <code>AbstractMP3Fragment</code> and represents the actual data of tags. It contains |
16 | * default get/set methods for all data objects. The data is represented as an ArrayList of <code>MP3Object</code>. |
17 | * ID3v2 tags have frames. Lyrics3 tags have fields. ID3v1 tags do not have fragments. |
18 | * |
19 | * @author Eric Farng |
20 | * @version $Revision: 1.6 $ |
21 | */ |
22 | public abstract class AbstractMP3FragmentBody extends AbstractMP3FileItem { |
23 | |
24 | private static final int SIZE_OBJECT_LIST = 16; |
25 | private static final int SIZE_BRIEF_DESCRIPTION = 64; |
26 | private static final int SIZE_DESCRIPTION = 256; |
27 | /** |
28 | * list of <code>MP3Object</code> |
29 | */ |
30 | private List objectList = new ArrayList(AbstractMP3FragmentBody.SIZE_OBJECT_LIST); |
31 | |
32 | /** |
33 | * Creates a new MP3FragmentBody object. |
34 | */ |
35 | protected AbstractMP3FragmentBody() { |
36 | super(); |
37 | setupObjectList(); |
38 | } |
39 | |
40 | /** |
41 | * Creates a new AbstractMP3FragmentBody object. |
42 | */ |
43 | protected AbstractMP3FragmentBody(final AbstractMP3FragmentBody copyObject) { |
44 | super(copyObject); |
45 | final Iterator iterator = copyObject.iterator(); |
46 | while (iterator.hasNext()) { |
47 | final AbstractMP3Object oldObject = (AbstractMP3Object) iterator.next(); |
48 | final AbstractMP3Object newObject = (AbstractMP3Object) TagUtility.copyObject(oldObject); |
49 | objectList.add(newObject); |
50 | } |
51 | } |
52 | |
53 | /** |
54 | * This method calls <code>toString</code> for all it's objects and appends them without any newline characters. |
55 | * |
56 | * @return brief description string |
57 | */ |
58 | public String getBriefDescription() { |
59 | final StringBuffer stringBuffer = new StringBuffer(AbstractMP3FragmentBody.SIZE_BRIEF_DESCRIPTION); |
60 | final Iterator iterator = objectList.listIterator(); |
61 | while (iterator.hasNext()) { |
62 | final AbstractMP3Object object = (AbstractMP3Object) iterator.next(); |
63 | final String objectToString = object.toString(); |
64 | if (objectToString != null && objectToString.length() > 0) { |
65 | final String identifier = object.getIdentifier(); |
66 | stringBuffer.append(identifier); |
67 | stringBuffer.append("=\""); |
68 | stringBuffer.append(objectToString); |
69 | stringBuffer.append("\"; "); |
70 | } |
71 | } |
72 | return stringBuffer.toString(); |
73 | } |
74 | |
75 | /** |
76 | * This method calls <code>toString</code> for all it's objects and appends them. It contains new line characters |
77 | * and is more suited for display purposes |
78 | * |
79 | * @return formatted description string |
80 | */ |
81 | public String getDescription() { |
82 | final StringBuffer stringBuffer = new StringBuffer(AbstractMP3FragmentBody.SIZE_DESCRIPTION); |
83 | final Iterator iterator = objectList.listIterator(); |
84 | while (iterator.hasNext()) { |
85 | final AbstractMP3Object object = (AbstractMP3Object) iterator.next(); |
86 | final String identifier = object.getIdentifier(); |
87 | stringBuffer.append(identifier); |
88 | stringBuffer.append(" = "); |
89 | final String string = object.toString(); |
90 | stringBuffer.append(string); |
91 | stringBuffer.append(TagConstant.SEPERATOR_LINE); |
92 | } |
93 | final String toString = stringBuffer.toString(); |
94 | return toString.trim(); |
95 | } |
96 | |
97 | public Iterator getObjectListIterator() { |
98 | return objectList.listIterator(); |
99 | } |
100 | |
101 | /** |
102 | * Sets the all objects of identifier type to <code>object</code> argument. |
103 | * |
104 | * @param identifier <code>MP3Object</code> identifier |
105 | * @param object new object value |
106 | */ |
107 | public void setObject(final String identifier, final Object object) { |
108 | final Iterator iterator = objectList.listIterator(); |
109 | while (iterator.hasNext()) { |
110 | final AbstractMP3Object abstractMP3Object = (AbstractMP3Object) iterator.next(); |
111 | final String currentIdentifier = abstractMP3Object.getIdentifier(); |
112 | if (currentIdentifier.equals(identifier)) { |
113 | abstractMP3Object.setValue(object); |
114 | } |
115 | } |
116 | } |
117 | |
118 | /** |
119 | * Returns the object of the <code>MP3Object</code> with the specified <code>identifier</code> |
120 | * |
121 | * @param identifier <code>MP3Object</code> identifier |
122 | * |
123 | * @return the object of the <code>MP3Object</code> with the specified <code>identifier</code> |
124 | */ |
125 | public Object getObject(final String identifier) { |
126 | Object object = null; |
127 | final Iterator iterator = objectList.listIterator(); |
128 | while (iterator.hasNext()) { |
129 | final AbstractMP3Object abstractMP3Object = (AbstractMP3Object) iterator.next(); |
130 | final String currentIdentifier = abstractMP3Object.getIdentifier(); |
131 | if (currentIdentifier.equals(identifier)) { |
132 | object = abstractMP3Object.getValue(); |
133 | } |
134 | } |
135 | return object; |
136 | } |
137 | |
138 | /** |
139 | * Returns the estimated size in bytes of this object if it was to be written to file. This is not guaranteed to be |
140 | * accurate 100% of the time. |
141 | * |
142 | * @return estimated size in bytes of this object |
143 | */ |
144 | public int getSize() { |
145 | //todo get this working 100% of the time |
146 | int size = 0; |
147 | final Iterator iterator = objectList.listIterator(); |
148 | while (iterator.hasNext()) { |
149 | final AbstractMP3Object object = (AbstractMP3Object) iterator.next(); |
150 | size += object.getSize(); |
151 | } |
152 | return size; |
153 | } |
154 | |
155 | /** |
156 | * Returns true if this instance and its entire <code>MP3Object</code> array list is a subset of the argument. This |
157 | * class is a subset if it is the same class as the argument. |
158 | * |
159 | * @param object object to determine subset of |
160 | * |
161 | * @return true if this instance and its entire object array list is a subset of the argument. |
162 | */ |
163 | public boolean isSubsetOf(final Object object) { |
164 | if (!super.isSubsetOf(object)) { |
165 | return false; |
166 | } |
167 | if (!(object instanceof AbstractMP3FragmentBody)) { |
168 | return false; |
169 | } |
170 | final List superset = ((AbstractMP3FragmentBody) object).objectList; |
171 | final int objectListSize = objectList.size(); |
172 | for (int i = 0; i < objectListSize; i++) { |
173 | final AbstractMP3Object abstractMP3Object = (AbstractMP3Object) objectList.get(i); |
174 | if (abstractMP3Object.getValue() != null && !superset.contains(abstractMP3Object)) { |
175 | return false; |
176 | } |
177 | } |
178 | return true; |
179 | } |
180 | |
181 | /** |
182 | * Returns true if this object and its entire <code>MP3Object</code> array list equals the argument. This object is |
183 | * equal to the argument only if they are the same class. |
184 | * |
185 | * @param obj object to determine equality of |
186 | * |
187 | * @return true if this object and its entire <code>MP3Object</code> array list equals the argument. |
188 | */ |
189 | public boolean equals(final Object obj) { |
190 | if (!(obj instanceof AbstractMP3FragmentBody)) { |
191 | return false; |
192 | } |
193 | final AbstractMP3FragmentBody abstractMP3FragmentBody = (AbstractMP3FragmentBody) obj; |
194 | if (!objectList.equals(abstractMP3FragmentBody.objectList)) { |
195 | return false; |
196 | } |
197 | return super.equals(obj); |
198 | } |
199 | |
200 | /** |
201 | * Returns an iterator of the <code>MP3Object</code> object list. |
202 | * |
203 | * @return iterator of the <code>MP3Object</code> object list. |
204 | */ |
205 | public Iterator iterator() { |
206 | return objectList.iterator(); |
207 | } |
208 | |
209 | protected void appendToObjectList(final AbstractMP3Object object) { |
210 | objectList.add(object); |
211 | } |
212 | |
213 | /** |
214 | * Read the data from the given file into this object. The file needs to have its file pointer in the correct |
215 | * location. |
216 | * |
217 | * @param file file to read from |
218 | * |
219 | * @throws IOException on any I/O error |
220 | * @throws InvalidTagException if there is any error in the data format. |
221 | */ |
222 | public void read(final RandomAccessFile file) throws IOException, InvalidTagException { |
223 | final int size = readHeader(file); |
224 | final byte[] buffer = new byte[size]; |
225 | file.read(buffer); |
226 | final Iterator iterator = objectList.listIterator(); |
227 | int offset = 0; |
228 | while (iterator.hasNext()) { |
229 | // sanjay@revasoft.com start bug fix |
230 | if (offset > size - 1) { |
231 | throw new InvalidTagException("Invalid size for Frame Body"); |
232 | } |
233 | |
234 | // sanjay@revasoft.com end bug fix |
235 | final AbstractMP3Object object = (AbstractMP3Object) iterator.next(); |
236 | object.readByteArray(buffer, offset); |
237 | offset += object.getSize(); |
238 | } |
239 | } |
240 | |
241 | /** |
242 | * Calls <code>toString</code> for all <code>MP3Object</code> objects and creates a string with a new line |
243 | * character. |
244 | * |
245 | * @return description string |
246 | */ |
247 | public String toString() { |
248 | final StringBuffer stringBuffer = new StringBuffer(AbstractMP3FragmentBody.SIZE_DESCRIPTION); |
249 | final String thisIdentifier = getIdentifier(); |
250 | stringBuffer.append(thisIdentifier); |
251 | stringBuffer.append(TagConstant.SEPERATOR_LINE); |
252 | final Iterator iterator = objectList.listIterator(); |
253 | while (iterator.hasNext()) { |
254 | final AbstractMP3Object object = (AbstractMP3Object) iterator.next(); |
255 | final String objectIdentifier = object.getIdentifier(); |
256 | stringBuffer.append(objectIdentifier); |
257 | stringBuffer.append(" = "); |
258 | final String string = object.toString(); |
259 | stringBuffer.append(string); |
260 | stringBuffer.append(TagConstant.SEPERATOR_LINE); |
261 | } |
262 | return stringBuffer.toString(); |
263 | } |
264 | |
265 | /** |
266 | * Write the contents of this object to the file at the position it is currently at. |
267 | * |
268 | * @param file destination file |
269 | * |
270 | * @throws IOException on any I/O error |
271 | */ |
272 | public void write(final RandomAccessFile file) throws IOException { |
273 | final int size = getSize(); |
274 | writeHeader(file, size); |
275 | final Iterator iterator = objectList.listIterator(); |
276 | while (iterator.hasNext()) { |
277 | final AbstractMP3Object object = (AbstractMP3Object) iterator.next(); |
278 | final byte[] buffer = object.writeByteArray(); |
279 | file.write(buffer); |
280 | } |
281 | } |
282 | |
283 | /** |
284 | * Reads the header for the fragment body. The header contains things such as the length. |
285 | * |
286 | * @param file file to read the header from. |
287 | * |
288 | * @return size of body in bytes as stated in the header. |
289 | * |
290 | * @throws IOException on any I/O error |
291 | * @throws InvalidTagException if there is any error in the data format. |
292 | */ |
293 | protected abstract int readHeader(RandomAccessFile file) throws IOException, InvalidTagException; |
294 | |
295 | /** |
296 | * Create the order of <code>MP3Object</code> objects that this body expects. This method needs to be overwritten. |
297 | */ |
298 | protected abstract void setupObjectList(); |
299 | |
300 | /** |
301 | * Write the body header to the file at the current file position. |
302 | * |
303 | * @param file file to write to |
304 | * @param size number of bytes the body contains. |
305 | * |
306 | * @throws IOException on any I/O error |
307 | */ |
308 | protected abstract void writeHeader(RandomAccessFile file, int size) throws IOException; |
309 | |
310 | protected static boolean has6ByteHeader() { |
311 | final Exception exception = new Exception(); |
312 | final StackTraceElement[] stackArray = exception.getStackTrace(); |
313 | final String id3v2_2name = ID3v2_2.class.getName(); |
314 | final String id3v2_3name = ID3v2_3.class.getName(); |
315 | final String id3v2_4name = ID3v2_4.class.getName(); |
316 | boolean has6ByteHeader = false; |
317 | boolean withinTag = false; |
318 | for (int i = stackArray.length - 1; i >= 0; i--) { |
319 | final String className = stackArray[i].getClassName(); |
320 | if (id3v2_2name.equals(className)) { |
321 | has6ByteHeader = true; |
322 | withinTag = true; |
323 | } else if (id3v2_3name.equals(className)) { |
324 | has6ByteHeader = false; |
325 | withinTag = true; |
326 | } else if (id3v2_4name.equals(className)) { |
327 | has6ByteHeader = false; |
328 | withinTag = true; |
329 | } |
330 | } |
331 | if (!withinTag) { |
332 | throw new UnsupportedOperationException("FragmentBody not called within ID3v2 tag."); |
333 | } |
334 | return has6ByteHeader; |
335 | } |
336 | } |