1 /*
2 * Copyright 2000-2004 Sun Microsystems, Inc. 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. Sun designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any questions.
24 */
25
26
27 package javax.print.attribute;
28
29 import java.io.Serializable;
30
31 /**
32 * Class AttributeSetUtilities provides static methods for manipulating
33 * AttributeSets.
34 * <ul>
35 * <li>Methods for creating unmodifiable and synchronized views of attribute
36 * sets.
37 * <li>operations useful for building
38 * implementations of interface {@link AttributeSet AttributeSet}
39 * </ul>
40 * <P>
41 * An <B>unmodifiable view</B> <I>U</I> of an AttributeSet <I>S</I> provides a
42 * client with "read-only" access to <I>S</I>. Query operations on <I>U</I>
43 * "read through" to <I>S</I>; thus, changes in <I>S</I> are reflected in
44 * <I>U</I>. However, any attempt to modify <I>U</I>,
45 * results in an UnmodifiableSetException.
46 * The unmodifiable view object <I>U</I> will be serializable if the
47 * attribute set object <I>S</I> is serializable.
48 * <P>
49 * A <B>synchronized view</B> <I>V</I> of an attribute set <I>S</I> provides a
50 * client with synchronized (multiple thread safe) access to <I>S</I>. Each
51 * operation of <I>V</I> is synchronized using <I>V</I> itself as the lock
52 * object and then merely invokes the corresponding operation of <I>S</I>. In
53 * order to guarantee mutually exclusive access, it is critical that all
54 * access to <I>S</I> is accomplished through <I>V</I>. The synchronized view
55 * object <I>V</I> will be serializable if the attribute set object <I>S</I>
56 * is serializable.
57 * <P>
58 * As mentioned in the package description of javax.print, a null reference
59 * parameter to methods is
60 * incorrect unless explicitly documented on the method as having a meaningful
61 * interpretation. Usage to the contrary is incorrect coding and may result in
62 * a run time exception either immediately
63 * or at some later time. IllegalArgumentException and NullPointerException
64 * are examples of typical and acceptable run time exceptions for such cases.
65 *
66 * @author Alan Kaminsky
67 */
68 public final class AttributeSetUtilities {
69
70 /* Suppress default constructor, ensuring non-instantiability.
71 */
72 private AttributeSetUtilities() {
73 }
74
75 /**
76 * @serial include
77 */
78 private static class UnmodifiableAttributeSet
79 implements AttributeSet, Serializable {
80
81 private AttributeSet attrset;
82
83 /* Unmodifiable view of the underlying attribute set.
84 */
85 public UnmodifiableAttributeSet(AttributeSet attributeSet) {
86
87 attrset = attributeSet;
88 }
89
90 public Attribute get(Class<?> key) {
91 return attrset.get(key);
92 }
93
94 public boolean add(Attribute attribute) {
95 throw new UnmodifiableSetException();
96 }
97
98 public synchronized boolean remove(Class<?> category) {
99 throw new UnmodifiableSetException();
100 }
101
102 public boolean remove(Attribute attribute) {
103 throw new UnmodifiableSetException();
104 }
105
106 public boolean containsKey(Class<?> category) {
107 return attrset.containsKey(category);
108 }
109
110 public boolean containsValue(Attribute attribute) {
111 return attrset.containsValue(attribute);
112 }
113
114 public boolean addAll(AttributeSet attributes) {
115 throw new UnmodifiableSetException();
116 }
117
118 public int size() {
119 return attrset.size();
120 }
121
122 public Attribute[] toArray() {
123 return attrset.toArray();
124 }
125
126 public void clear() {
127 throw new UnmodifiableSetException();
128 }
129
130 public boolean isEmpty() {
131 return attrset.isEmpty();
132 }
133
134 public boolean equals(Object o) {
135 return attrset.equals (o);
136 }
137
138 public int hashCode() {
139 return attrset.hashCode();
140 }
141
142 }
143
144 /**
145 * @serial include
146 */
147 private static class UnmodifiableDocAttributeSet
148 extends UnmodifiableAttributeSet
149 implements DocAttributeSet, Serializable {
150
151 public UnmodifiableDocAttributeSet(DocAttributeSet attributeSet) {
152
153 super (attributeSet);
154 }
155 }
156
157 /**
158 * @serial include
159 */
160 private static class UnmodifiablePrintRequestAttributeSet
161 extends UnmodifiableAttributeSet
162 implements PrintRequestAttributeSet, Serializable
163 {
164 public UnmodifiablePrintRequestAttributeSet
165 (PrintRequestAttributeSet attributeSet) {
166
167 super (attributeSet);
168 }
169 }
170
171 /**
172 * @serial include
173 */
174 private static class UnmodifiablePrintJobAttributeSet
175 extends UnmodifiableAttributeSet
176 implements PrintJobAttributeSet, Serializable
177 {
178 public UnmodifiablePrintJobAttributeSet
179 (PrintJobAttributeSet attributeSet) {
180
181 super (attributeSet);
182 }
183 }
184
185 /**
186 * @serial include
187 */
188 private static class UnmodifiablePrintServiceAttributeSet
189 extends UnmodifiableAttributeSet
190 implements PrintServiceAttributeSet, Serializable
191 {
192 public UnmodifiablePrintServiceAttributeSet
193 (PrintServiceAttributeSet attributeSet) {
194
195 super (attributeSet);
196 }
197 }
198
199 /**
200 * Creates an unmodifiable view of the given attribute set.
201 *
202 * @param attributeSet Underlying attribute set.
203 *
204 * @return Unmodifiable view of <CODE>attributeSet</CODE>.
205 *
206 * @exception NullPointerException
207 * Thrown if <CODE>attributeSet</CODE> is null. Null is never a
208 */
209 public static AttributeSet unmodifiableView(AttributeSet attributeSet) {
210 if (attributeSet == null) {
211 throw new NullPointerException();
212 }
213
214 return new UnmodifiableAttributeSet(attributeSet);
215 }
216
217 /**
218 * Creates an unmodifiable view of the given doc attribute set.
219 *
220 * @param attributeSet Underlying doc attribute set.
221 *
222 * @return Unmodifiable view of <CODE>attributeSet</CODE>.
223 *
224 * @exception NullPointerException
225 * Thrown if <CODE>attributeSet</CODE> is null.
226 */
227 public static DocAttributeSet unmodifiableView
228 (DocAttributeSet attributeSet) {
229 if (attributeSet == null) {
230 throw new NullPointerException();
231 }
232 return new UnmodifiableDocAttributeSet(attributeSet);
233 }
234
235 /**
236 * Creates an unmodifiable view of the given print request attribute set.
237 *
238 * @param attributeSet Underlying print request attribute set.
239 *
240 * @return Unmodifiable view of <CODE>attributeSet</CODE>.
241 *
242 * @exception NullPointerException
243 * Thrown if <CODE>attributeSet</CODE> is null.
244 */
245 public static PrintRequestAttributeSet
246 unmodifiableView(PrintRequestAttributeSet attributeSet) {
247 if (attributeSet == null) {
248 throw new NullPointerException();
249 }
250 return new UnmodifiablePrintRequestAttributeSet(attributeSet);
251 }
252
253 /**
254 * Creates an unmodifiable view of the given print job attribute set.
255 *
256 * @param attributeSet Underlying print job attribute set.
257 *
258 * @return Unmodifiable view of <CODE>attributeSet</CODE>.
259 *
260 * @exception NullPointerException
261 * Thrown if <CODE>attributeSet</CODE> is null.
262 */
263 public static PrintJobAttributeSet
264 unmodifiableView(PrintJobAttributeSet attributeSet) {
265 if (attributeSet == null) {
266 throw new NullPointerException();
267 }
268 return new UnmodifiablePrintJobAttributeSet(attributeSet);
269 }
270
271 /**
272 * Creates an unmodifiable view of the given print service attribute set.
273 *
274 * @param attributeSet Underlying print service attribute set.
275 *
276 * @return Unmodifiable view of <CODE>attributeSet</CODE>.
277 *
278 * @exception NullPointerException
279 * Thrown if <CODE>attributeSet</CODE> is null.
280 */
281 public static PrintServiceAttributeSet
282 unmodifiableView(PrintServiceAttributeSet attributeSet) {
283 if (attributeSet == null) {
284 throw new NullPointerException();
285 }
286 return new UnmodifiablePrintServiceAttributeSet (attributeSet);
287 }
288
289 /**
290 * @serial include
291 */
292 private static class SynchronizedAttributeSet
293 implements AttributeSet, Serializable {
294
295 private AttributeSet attrset;
296
297 public SynchronizedAttributeSet(AttributeSet attributeSet) {
298 attrset = attributeSet;
299 }
300
301 public synchronized Attribute get(Class<?> category) {
302 return attrset.get(category);
303 }
304
305 public synchronized boolean add(Attribute attribute) {
306 return attrset.add(attribute);
307 }
308
309 public synchronized boolean remove(Class<?> category) {
310 return attrset.remove(category);
311 }
312
313 public synchronized boolean remove(Attribute attribute) {
314 return attrset.remove(attribute);
315 }
316
317 public synchronized boolean containsKey(Class<?> category) {
318 return attrset.containsKey(category);
319 }
320
321 public synchronized boolean containsValue(Attribute attribute) {
322 return attrset.containsValue(attribute);
323 }
324
325 public synchronized boolean addAll(AttributeSet attributes) {
326 return attrset.addAll(attributes);
327 }
328
329 public synchronized int size() {
330 return attrset.size();
331 }
332
333 public synchronized Attribute[] toArray() {
334 return attrset.toArray();
335 }
336
337 public synchronized void clear() {
338 attrset.clear();
339 }
340
341 public synchronized boolean isEmpty() {
342 return attrset.isEmpty();
343 }
344
345 public synchronized boolean equals(Object o) {
346 return attrset.equals (o);
347 }
348
349 public synchronized int hashCode() {
350 return attrset.hashCode();
351 }
352 }
353
354 /**
355 * @serial include
356 */
357 private static class SynchronizedDocAttributeSet
358 extends SynchronizedAttributeSet
359 implements DocAttributeSet, Serializable {
360
361 public SynchronizedDocAttributeSet(DocAttributeSet attributeSet) {
362 super(attributeSet);
363 }
364 }
365
366 /**
367 * @serial include
368 */
369 private static class SynchronizedPrintRequestAttributeSet
370 extends SynchronizedAttributeSet
371 implements PrintRequestAttributeSet, Serializable {
372
373 public SynchronizedPrintRequestAttributeSet
374 (PrintRequestAttributeSet attributeSet) {
375 super(attributeSet);
376 }
377 }
378
379 /**
380 * @serial include
381 */
382 private static class SynchronizedPrintJobAttributeSet
383 extends SynchronizedAttributeSet
384 implements PrintJobAttributeSet, Serializable {
385
386 public SynchronizedPrintJobAttributeSet
387 (PrintJobAttributeSet attributeSet) {
388 super(attributeSet);
389 }
390 }
391
392 /**
393 * @serial include
394 */
395 private static class SynchronizedPrintServiceAttributeSet
396 extends SynchronizedAttributeSet
397 implements PrintServiceAttributeSet, Serializable {
398 public SynchronizedPrintServiceAttributeSet
399 (PrintServiceAttributeSet attributeSet) {
400 super(attributeSet);
401 }
402 }
403
404 /**
405 * Creates a synchronized view of the given attribute set.
406 *
407 * @param attributeSet Underlying attribute set.
408 *
409 * @return Synchronized view of <CODE>attributeSet</CODE>.
410 *
411 * @exception NullPointerException
412 * Thrown if <CODE>attributeSet</CODE> is null.
413 */
414 public static AttributeSet synchronizedView
415 (AttributeSet attributeSet) {
416 if (attributeSet == null) {
417 throw new NullPointerException();
418 }
419 return new SynchronizedAttributeSet(attributeSet);
420 }
421
422 /**
423 * Creates a synchronized view of the given doc attribute set.
424 *
425 * @param attributeSet Underlying doc attribute set.
426 *
427 * @return Synchronized view of <CODE>attributeSet</CODE>.
428 *
429 * @exception NullPointerException
430 * Thrown if <CODE>attributeSet</CODE> is null.
431 */
432 public static DocAttributeSet
433 synchronizedView(DocAttributeSet attributeSet) {
434 if (attributeSet == null) {
435 throw new NullPointerException();
436 }
437 return new SynchronizedDocAttributeSet(attributeSet);
438 }
439
440 /**
441 * Creates a synchronized view of the given print request attribute set.
442 *
443 * @param attributeSet Underlying print request attribute set.
444 *
445 * @return Synchronized view of <CODE>attributeSet</CODE>.
446 *
447 * @exception NullPointerException
448 * Thrown if <CODE>attributeSet</CODE> is null.
449 */
450 public static PrintRequestAttributeSet
451 synchronizedView(PrintRequestAttributeSet attributeSet) {
452 if (attributeSet == null) {
453 throw new NullPointerException();
454 }
455 return new SynchronizedPrintRequestAttributeSet(attributeSet);
456 }
457
458 /**
459 * Creates a synchronized view of the given print job attribute set.
460 *
461 * @param attributeSet Underlying print job attribute set.
462 *
463 * @return Synchronized view of <CODE>attributeSet</CODE>.
464 *
465 * @exception NullPointerException
466 * Thrown if <CODE>attributeSet</CODE> is null.
467 */
468 public static PrintJobAttributeSet
469 synchronizedView(PrintJobAttributeSet attributeSet) {
470 if (attributeSet == null) {
471 throw new NullPointerException();
472 }
473 return new SynchronizedPrintJobAttributeSet(attributeSet);
474 }
475
476 /**
477 * Creates a synchronized view of the given print service attribute set.
478 *
479 * @param attributeSet Underlying print service attribute set.
480 *
481 * @return Synchronized view of <CODE>attributeSet</CODE>.
482 */
483 public static PrintServiceAttributeSet
484 synchronizedView(PrintServiceAttributeSet attributeSet) {
485 if (attributeSet == null) {
486 throw new NullPointerException();
487 }
488 return new SynchronizedPrintServiceAttributeSet(attributeSet);
489 }
490
491
492 /**
493 * Verify that the given object is a {@link java.lang.Class Class} that
494 * implements the given interface, which is assumed to be interface {@link
495 * Attribute Attribute} or a subinterface thereof.
496 *
497 * @param object Object to test.
498 * @param interfaceName Interface the object must implement.
499 *
500 * @return If <CODE>object</CODE> is a {@link java.lang.Class Class}
501 * that implements <CODE>interfaceName</CODE>,
502 * <CODE>object</CODE> is returned downcast to type {@link
503 * java.lang.Class Class}; otherwise an exception is thrown.
504 *
505 * @exception NullPointerException
506 * (unchecked exception) Thrown if <CODE>object</CODE> is null.
507 * @exception ClassCastException
508 * (unchecked exception) Thrown if <CODE>object</CODE> is not a
509 * {@link java.lang.Class Class} that implements
510 * <CODE>interfaceName</CODE>.
511 */
512 public static Class<?>
513 verifyAttributeCategory(Object object, Class<?> interfaceName) {
514
515 Class result = (Class) object;
516 if (interfaceName.isAssignableFrom (result)) {
517 return result;
518 }
519 else {
520 throw new ClassCastException();
521 }
522 }
523
524 /**
525 * Verify that the given object is an instance of the given interface, which
526 * is assumed to be interface {@link Attribute Attribute} or a subinterface
527 * thereof.
528 *
529 * @param object Object to test.
530 * @param interfaceName Interface of which the object must be an instance.
531 *
532 * @return If <CODE>object</CODE> is an instance of
533 * <CODE>interfaceName</CODE>, <CODE>object</CODE> is returned
534 * downcast to type {@link Attribute Attribute}; otherwise an
535 * exception is thrown.
536 *
537 * @exception NullPointerException
538 * (unchecked exception) Thrown if <CODE>object</CODE> is null.
539 * @exception ClassCastException
540 * (unchecked exception) Thrown if <CODE>object</CODE> is not an
541 * instance of <CODE>interfaceName</CODE>.
542 */
543 public static Attribute
544 verifyAttributeValue(Object object, Class<?> interfaceName) {
545
546 if (object == null) {
547 throw new NullPointerException();
548 }
549 else if (interfaceName.isInstance (object)) {
550 return (Attribute) object;
551 } else {
552 throw new ClassCastException();
553 }
554 }
555
556 /**
557 * Verify that the given attribute category object is equal to the
558 * category of the given attribute value object. If so, this method
559 * returns doing nothing. If not, this method throws an exception.
560 *
561 * @param category Attribute category to test.
562 * @param attribute Attribute value to test.
563 *
564 * @exception NullPointerException
565 * (unchecked exception) Thrown if the <CODE>category</CODE> is
566 * null or if the <CODE>attribute</CODE> is null.
567 * @exception IllegalArgumentException
568 * (unchecked exception) Thrown if the <CODE>category</CODE> is not
569 * equal to the category of the <CODE>attribute</CODE>.
570 */
571 public static void
572 verifyCategoryForValue(Class<?> category, Attribute attribute) {
573
574 if (!category.equals (attribute.getCategory())) {
575 throw new IllegalArgumentException();
576 }
577 }
578 }
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