1 /*
2 * Copyright (c) 2000, 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package javax.print.attribute;
27
28 import java.io.IOException;
29 import java.io.ObjectInputStream;
30 import java.io.ObjectOutputStream;
31 import java.io.Serializable;
32 import java.util.HashMap;
33
34 /**
35 * Class HashAttributeSet provides an <code>AttributeSet</code>
36 * implementation with characteristics of a hash map.
37 *
38 * @author Alan Kaminsky
39 */
40 public class HashAttributeSet implements AttributeSet, Serializable {
41
42 private static final long serialVersionUID = 5311560590283707917L;
43
44 /**
45 * The interface of which all members of this attribute set must be an
46 * instance. It is assumed to be interface {@link Attribute Attribute}
47 * or a subinterface thereof.
48 * @serial
49 */
50 private Class myInterface;
51
52 /*
53 * A HashMap used by the implementation.
54 * The serialised form doesn't include this instance variable.
55 */
56 private transient HashMap attrMap = new HashMap();
57
58 /**
59 * Write the instance to a stream (ie serialize the object)
60 *
61 * @serialData
62 * The serialized form of an attribute set explicitly writes the
63 * number of attributes in the set, and each of the attributes.
64 * This does not guarantee equality of serialized forms since
65 * the order in which the attributes are written is not defined.
66 */
67 private void writeObject(ObjectOutputStream s) throws IOException {
68
69 s.defaultWriteObject();
70 Attribute [] attrs = toArray();
71 s.writeInt(attrs.length);
72 for (int i = 0; i < attrs.length; i++) {
73 s.writeObject(attrs[i]);
74 }
75 }
76
77 /**
78 * Reconstitute an instance from a stream that is, deserialize it).
79 */
80 private void readObject(ObjectInputStream s)
81 throws ClassNotFoundException, IOException {
82
83 s.defaultReadObject();
84 attrMap = new HashMap();
85 int count = s.readInt();
86 Attribute attr;
87 for (int i = 0; i < count; i++) {
88 attr = (Attribute)s.readObject();
89 add(attr);
90 }
91 }
92
93 /**
94 * Construct a new, empty attribute set.
95 */
96 public HashAttributeSet() {
97 this(Attribute.class);
98 }
99
100 /**
101 * Construct a new attribute set,
102 * initially populated with the given attribute.
103 *
104 * @param attribute Attribute value to add to the set.
105 *
106 * @exception NullPointerException
107 * (unchecked exception) Thrown if <CODE>attribute</CODE> is null.
108 */
109 public HashAttributeSet(Attribute attribute) {
110 this (attribute, Attribute.class);
111 }
112
113 /**
114 * Construct a new attribute set,
115 * initially populated with the values from the
116 * given array. The new attribute set is populated by
117 * adding the elements of <CODE>attributes</CODE> array to the set in
118 * sequence, starting at index 0. Thus, later array elements may replace
119 * earlier array elements if the array contains duplicate attribute
120 * values or attribute categories.
121 *
122 * @param attributes Array of attribute values to add to the set.
123 * If null, an empty attribute set is constructed.
124 *
125 * @exception NullPointerException
126 * (unchecked exception) Thrown if any element of
127 * <CODE>attributes</CODE> is null.
128 */
129 public HashAttributeSet(Attribute[] attributes) {
130 this (attributes, Attribute.class);
131 }
132
133 /**
134 * Construct a new attribute set,
135 * initially populated with the values from the given set.
136 *
137 * @param attributes Set of attributes from which to initialise this set.
138 * If null, an empty attribute set is constructed.
139 *
140 */
141 public HashAttributeSet(AttributeSet attributes) {
142 this (attributes, Attribute.class);
143 }
144
145 /**
146 * Construct a new, empty attribute set, where the members of
147 * the attribute set are restricted to the given interface.
148 *
149 * @param interfaceName The interface of which all members of this
150 * attribute set must be an instance. It is assumed to
151 * be interface {@link Attribute Attribute} or a
152 * subinterface thereof.
153 * @exception NullPointerException if interfaceName is null.
154 */
155 protected HashAttributeSet(Class<?> interfaceName) {
156 if (interfaceName == null) {
157 throw new NullPointerException("null interface");
158 }
159 myInterface = interfaceName;
160 }
161
162 /**
163 * Construct a new attribute set, initially populated with the given
164 * attribute, where the members of the attribute set are restricted to the
165 * given interface.
166 *
167 * @param attribute Attribute value to add to the set.
168 * @param interfaceName The interface of which all members of this
169 * attribute set must be an instance. It is assumed to
170 * be interface {@link Attribute Attribute} or a
171 * subinterface thereof.
172 *
173 * @exception NullPointerException
174 * (unchecked exception) Thrown if <CODE>attribute</CODE> is null.
175 * @exception NullPointerException if interfaceName is null.
176 * @exception ClassCastException
177 * (unchecked exception) Thrown if <CODE>attribute</CODE> is not an
178 * instance of <CODE>interfaceName</CODE>.
179 */
180 protected HashAttributeSet(Attribute attribute, Class<?> interfaceName) {
181 if (interfaceName == null) {
182 throw new NullPointerException("null interface");
183 }
184 myInterface = interfaceName;
185 add (attribute);
186 }
187
188 /**
189 * Construct a new attribute set, where the members of the attribute
190 * set are restricted to the given interface.
191 * The new attribute set is populated
192 * by adding the elements of <CODE>attributes</CODE> array to the set in
193 * sequence, starting at index 0. Thus, later array elements may replace
194 * earlier array elements if the array contains duplicate attribute
195 * values or attribute categories.
196 *
197 * @param attributes Array of attribute values to add to the set. If
198 * null, an empty attribute set is constructed.
199 * @param interfaceName The interface of which all members of this
200 * attribute set must be an instance. It is assumed to
201 * be interface {@link Attribute Attribute} or a
202 * subinterface thereof.
203 *
204 * @exception NullPointerException
205 * (unchecked exception) Thrown if any element of
206 * <CODE>attributes</CODE> is null.
207 * @exception NullPointerException if interfaceName is null.
208 * @exception ClassCastException
209 * (unchecked exception) Thrown if any element of
210 * <CODE>attributes</CODE> is not an instance of
211 * <CODE>interfaceName</CODE>.
212 */
213 protected HashAttributeSet(Attribute[] attributes, Class<?> interfaceName) {
214 if (interfaceName == null) {
215 throw new NullPointerException("null interface");
216 }
217 myInterface = interfaceName;
218 int n = attributes == null ? 0 : attributes.length;
219 for (int i = 0; i < n; ++ i) {
220 add (attributes[i]);
221 }
222 }
223
224 /**
225 * Construct a new attribute set, initially populated with the
226 * values from the given set where the members of the attribute
227 * set are restricted to the given interface.
228 *
229 * @param attributes set of attribute values to initialise the set. If
230 * null, an empty attribute set is constructed.
231 * @param interfaceName The interface of which all members of this
232 * attribute set must be an instance. It is assumed to
233 * be interface {@link Attribute Attribute} or a
234 * subinterface thereof.
235 *
236 * @exception ClassCastException
237 * (unchecked exception) Thrown if any element of
238 * <CODE>attributes</CODE> is not an instance of
239 * <CODE>interfaceName</CODE>.
240 */
241 protected HashAttributeSet(AttributeSet attributes, Class<?> interfaceName) {
242 myInterface = interfaceName;
243 if (attributes != null) {
244 Attribute[] attribArray = attributes.toArray();
245 int n = attribArray == null ? 0 : attribArray.length;
246 for (int i = 0; i < n; ++ i) {
247 add (attribArray[i]);
248 }
249 }
250 }
251
252 /**
253 * Returns the attribute value which this attribute set contains in the
254 * given attribute category. Returns <tt>null</tt> if this attribute set
255 * does not contain any attribute value in the given attribute category.
256 *
257 * @param category Attribute category whose associated attribute value
258 * is to be returned. It must be a
259 * {@link java.lang.Class Class}
260 * that implements interface {@link Attribute
261 * Attribute}.
262 *
263 * @return The attribute value in the given attribute category contained
264 * in this attribute set, or <tt>null</tt> if this attribute set
265 * does not contain any attribute value in the given attribute
266 * category.
267 *
268 * @throws NullPointerException
269 * (unchecked exception) Thrown if the <CODE>category</CODE> is null.
270 * @throws ClassCastException
271 * (unchecked exception) Thrown if the <CODE>category</CODE> is not a
272 * {@link java.lang.Class Class} that implements interface {@link
273 * Attribute Attribute}.
274 */
275 public Attribute get(Class<?> category) {
276 return (Attribute)
277 attrMap.get(AttributeSetUtilities.
278 verifyAttributeCategory(category,
279 Attribute.class));
280 }
281
282 /**
283 * Adds the specified attribute to this attribute set if it is not
284 * already present, first removing any existing in the same
285 * attribute category as the specified attribute value.
286 *
287 * @param attribute Attribute value to be added to this attribute set.
288 *
289 * @return <tt>true</tt> if this attribute set changed as a result of the
290 * call, i.e., the given attribute value was not already a
291 * member of this attribute set.
292 *
293 * @throws NullPointerException
294 * (unchecked exception) Thrown if the <CODE>attribute</CODE> is null.
295 * @throws UnmodifiableSetException
296 * (unchecked exception) Thrown if this attribute set does not support
297 * the <CODE>add()</CODE> operation.
298 */
299 public boolean add(Attribute attribute) {
300 Object oldAttribute =
301 attrMap.put(attribute.getCategory(),
302 AttributeSetUtilities.
303 verifyAttributeValue(attribute, myInterface));
304 return (!attribute.equals(oldAttribute));
305 }
306
307 /**
308 * Removes any attribute for this category from this attribute set if
309 * present. If <CODE>category</CODE> is null, then
310 * <CODE>remove()</CODE> does nothing and returns <tt>false</tt>.
311 *
312 * @param category Attribute category to be removed from this
313 * attribute set.
314 *
315 * @return <tt>true</tt> if this attribute set changed as a result of the
316 * call, i.e., the given attribute category had been a member of
317 * this attribute set.
318 *
319 * @throws UnmodifiableSetException
320 * (unchecked exception) Thrown if this attribute set does not
321 * support the <CODE>remove()</CODE> operation.
322 */
323 public boolean remove(Class<?> category) {
324 return
325 category != null &&
326 AttributeSetUtilities.
327 verifyAttributeCategory(category, Attribute.class) != null &&
328 attrMap.remove(category) != null;
329 }
330
331 /**
332 * Removes the specified attribute from this attribute set if
333 * present. If <CODE>attribute</CODE> is null, then
334 * <CODE>remove()</CODE> does nothing and returns <tt>false</tt>.
335 *
336 * @param attribute Attribute value to be removed from this attribute set.
337 *
338 * @return <tt>true</tt> if this attribute set changed as a result of the
339 * call, i.e., the given attribute value had been a member of
340 * this attribute set.
341 *
342 * @throws UnmodifiableSetException
343 * (unchecked exception) Thrown if this attribute set does not
344 * support the <CODE>remove()</CODE> operation.
345 */
346 public boolean remove(Attribute attribute) {
347 return
348 attribute != null &&
349 attrMap.remove(attribute.getCategory()) != null;
350 }
351
352 /**
353 * Returns <tt>true</tt> if this attribute set contains an
354 * attribute for the specified category.
355 *
356 * @param category whose presence in this attribute set is
357 * to be tested.
358 *
359 * @return <tt>true</tt> if this attribute set contains an attribute
360 * value for the specified category.
361 */
362 public boolean containsKey(Class<?> category) {
363 return
364 category != null &&
365 AttributeSetUtilities.
366 verifyAttributeCategory(category, Attribute.class) != null &&
367 attrMap.get(category) != null;
368 }
369
370 /**
371 * Returns <tt>true</tt> if this attribute set contains the given
372 * attribute.
373 *
374 * @param attribute value whose presence in this attribute set is
375 * to be tested.
376 *
377 * @return <tt>true</tt> if this attribute set contains the given
378 * attribute value.
379 */
380 public boolean containsValue(Attribute attribute) {
381 return
382 attribute != null &&
383 attribute instanceof Attribute &&
384 attribute.equals(attrMap.get(attribute.getCategory()));
385 }
386
387 /**
388 * Adds all of the elements in the specified set to this attribute.
389 * The outcome is the same as if the
390 * {@link #add(Attribute) add(Attribute)}
391 * operation had been applied to this attribute set successively with
392 * each element from the specified set.
393 * The behavior of the <CODE>addAll(AttributeSet)</CODE>
394 * operation is unspecified if the specified set is modified while
395 * the operation is in progress.
396 * <P>
397 * If the <CODE>addAll(AttributeSet)</CODE> operation throws an exception,
398 * the effect on this attribute set's state is implementation dependent;
399 * elements from the specified set before the point of the exception may
400 * or may not have been added to this attribute set.
401 *
402 * @param attributes whose elements are to be added to this attribute
403 * set.
404 *
405 * @return <tt>true</tt> if this attribute set changed as a result of the
406 * call.
407 *
408 * @throws UnmodifiableSetException
409 * (Unchecked exception) Thrown if this attribute set does not
410 * support the <tt>addAll(AttributeSet)</tt> method.
411 * @throws NullPointerException
412 * (Unchecked exception) Thrown if some element in the specified
413 * set is null, or the set is null.
414 *
415 * @see #add(Attribute)
416 */
417 public boolean addAll(AttributeSet attributes) {
418
419 Attribute []attrs = attributes.toArray();
420 boolean result = false;
421 for (int i=0; i<attrs.length; i++) {
422 Attribute newValue =
423 AttributeSetUtilities.verifyAttributeValue(attrs[i],
424 myInterface);
425 Object oldValue = attrMap.put(newValue.getCategory(), newValue);
426 result = (! newValue.equals(oldValue)) || result;
427 }
428 return result;
429 }
430
431 /**
432 * Returns the number of attributes in this attribute set. If this
433 * attribute set contains more than <tt>Integer.MAX_VALUE</tt> elements,
434 * returns <tt>Integer.MAX_VALUE</tt>.
435 *
436 * @return The number of attributes in this attribute set.
437 */
438 public int size() {
439 return attrMap.size();
440 }
441
442 /**
443 *
444 * @return the Attributes contained in this set as an array, zero length
445 * if the AttributeSet is empty.
446 */
447 public Attribute[] toArray() {
448 Attribute []attrs = new Attribute[size()];
449 attrMap.values().toArray(attrs);
450 return attrs;
451 }
452
453
454 /**
455 * Removes all attributes from this attribute set.
456 *
457 * @throws UnmodifiableSetException
458 * (unchecked exception) Thrown if this attribute set does not support
459 * the <CODE>clear()</CODE> operation.
460 */
461 public void clear() {
462 attrMap.clear();
463 }
464
465 /**
466 * Returns true if this attribute set contains no attributes.
467 *
468 * @return true if this attribute set contains no attributes.
469 */
470 public boolean isEmpty() {
471 return attrMap.isEmpty();
472 }
473
474 /**
475 * Compares the specified object with this attribute set for equality.
476 * Returns <tt>true</tt> if the given object is also an attribute set and
477 * the two attribute sets contain the same attribute category-attribute
478 * value mappings. This ensures that the
479 * <tt>equals()</tt> method works properly across different
480 * implementations of the AttributeSet interface.
481 *
482 * @param object to be compared for equality with this attribute set.
483 *
484 * @return <tt>true</tt> if the specified object is equal to this
485 * attribute set.
486 */
487
488 public boolean equals(Object object) {
489 if (object == null || !(object instanceof AttributeSet)) {
490 return false;
491 }
492
493 AttributeSet aset = (AttributeSet)object;
494 if (aset.size() != size()) {
495 return false;
496 }
497
498 Attribute[] attrs = toArray();
499 for (int i=0;i<attrs.length; i++) {
500 if (!aset.containsValue(attrs[i])) {
501 return false;
502 }
503 }
504 return true;
505 }
506
507 /**
508 * Returns the hash code value for this attribute set.
509 * The hash code of an attribute set is defined to be the sum
510 * of the hash codes of each entry in the AttributeSet.
511 * This ensures that <tt>t1.equals(t2)</tt> implies that
512 * <tt>t1.hashCode()==t2.hashCode()</tt> for any two attribute sets
513 * <tt>t1</tt> and <tt>t2</tt>, as required by the general contract of
514 * {@link java.lang.Object#hashCode() Object.hashCode()}.
515 *
516 * @return The hash code value for this attribute set.
517 */
518 public int hashCode() {
519 int hcode = 0;
520 Attribute[] attrs = toArray();
521 for (int i=0;i<attrs.length; i++) {
522 hcode += attrs[i].hashCode();
523 }
524 return hcode;
525 }
526
527 }