1 /*
2 * Copyright (c) 1997, 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 java.awt.datatransfer;
27
28 import java.awt.Toolkit;
29
30 import java.lang.ref.SoftReference;
31
32 import java.io.BufferedReader;
33 import java.io.File;
34 import java.io.InputStreamReader;
35 import java.io.IOException;
36
37 import java.net.URL;
38 import java.net.MalformedURLException;
39
40 import java.util.ArrayList;
41 import java.util.HashMap;
42 import java.util.HashSet;
43 import java.util.LinkedHashSet;
44 import java.util.List;
45 import java.util.Map;
46 import java.util.Set;
47 import java.util.WeakHashMap;
48
49 import sun.awt.AppContext;
50 import sun.awt.datatransfer.DataTransferer;
51
52 /**
53 * The SystemFlavorMap is a configurable map between "natives" (Strings), which
54 * correspond to platform-specific data formats, and "flavors" (DataFlavors),
55 * which correspond to platform-independent MIME types. This mapping is used
56 * by the data transfer subsystem to transfer data between Java and native
57 * applications, and between Java applications in separate VMs.
58 *
59 * @since 1.2
60 */
61 public final class SystemFlavorMap implements FlavorMap, FlavorTable {
62
63 /**
64 * Constant prefix used to tag Java types converted to native platform
65 * type.
66 */
67 private static String JavaMIME = "JAVA_DATAFLAVOR:";
68
69 private static final Object FLAVOR_MAP_KEY = new Object();
70
71 /**
72 * Copied from java.util.Properties.
73 */
74 private static final String keyValueSeparators = "=: \t\r\n\f";
75 private static final String strictKeyValueSeparators = "=:";
76 private static final String whiteSpaceChars = " \t\r\n\f";
77
78 /**
79 * The list of valid, decoded text flavor representation classes, in order
80 * from best to worst.
81 */
82 private static final String[] UNICODE_TEXT_CLASSES = {
83 "java.io.Reader", "java.lang.String", "java.nio.CharBuffer", "\"[C\""
84 };
85
86 /**
87 * The list of valid, encoded text flavor representation classes, in order
88 * from best to worst.
89 */
90 private static final String[] ENCODED_TEXT_CLASSES = {
91 "java.io.InputStream", "java.nio.ByteBuffer", "\"[B\""
92 };
93
94 /**
95 * A String representing text/plain MIME type.
96 */
97 private static final String TEXT_PLAIN_BASE_TYPE = "text/plain";
98
99 /**
100 * A String representing text/html MIME type.
101 */
102 private static final String HTML_TEXT_BASE_TYPE = "text/html";
103
104 /**
105 * This constant is passed to flavorToNativeLookup() to indicate that a
106 * a native should be synthesized, stored, and returned by encoding the
107 * DataFlavor's MIME type in case if the DataFlavor is not found in
108 * 'flavorToNative' map.
109 */
110 private static final boolean SYNTHESIZE_IF_NOT_FOUND = true;
111
112 /**
113 * Maps native Strings to Lists of DataFlavors (or base type Strings for
114 * text DataFlavors).
115 * Do not use the field directly, use getNativeToFlavor() instead.
116 */
117 private final Map<String, List<DataFlavor>> nativeToFlavor = new HashMap<>();
118
119 /**
120 * Accessor to nativeToFlavor map. Since we use lazy initialization we must
121 * use this accessor instead of direct access to the field which may not be
122 * initialized yet. This method will initialize the field if needed.
123 *
124 * @return nativeToFlavor
125 */
126 private Map<String, List<DataFlavor>> getNativeToFlavor() {
127 if (!isMapInitialized) {
128 initSystemFlavorMap();
129 }
130 return nativeToFlavor;
131 }
132
133 /**
134 * Maps DataFlavors (or base type Strings for text DataFlavors) to Lists of
135 * native Strings.
136 * Do not use the field directly, use getFlavorToNative() instead.
137 */
138 private final Map<DataFlavor, List<String>> flavorToNative = new HashMap<>();
139
140 /**
141 * Accessor to flavorToNative map. Since we use lazy initialization we must
142 * use this accessor instead of direct access to the field which may not be
143 * initialized yet. This method will initialize the field if needed.
144 *
145 * @return flavorToNative
146 */
147 private synchronized Map<DataFlavor, List<String>> getFlavorToNative() {
148 if (!isMapInitialized) {
149 initSystemFlavorMap();
150 }
151 return flavorToNative;
152 }
153
154 /**
155 * Shows if the object has been initialized.
156 */
157 private boolean isMapInitialized = false;
158
159 /**
160 * Caches the result of getNativesForFlavor(). Maps DataFlavors to
161 * SoftReferences which reference Lists of String natives.
162 */
163 private Map<DataFlavor, SoftReference<List<String>>> getNativesForFlavorCache = new HashMap<>();
164
165 /**
166 * Caches the result getFlavorsForNative(). Maps String natives to
167 * SoftReferences which reference Lists of DataFlavors.
168 */
169 private Map<String, SoftReference<List<DataFlavor>>> getFlavorsForNativeCache = new HashMap<>();
170
171 /**
172 * Dynamic mapping generation used for text mappings should not be applied
173 * to the DataFlavors and String natives for which the mappings have been
174 * explicitly specified with setFlavorsForNative() or
175 * setNativesForFlavor(). This keeps all such keys.
176 */
177 private Set disabledMappingGenerationKeys = new HashSet();
178
179 /**
180 * Returns the default FlavorMap for this thread's ClassLoader.
181 * @return the default FlavorMap for this thread's ClassLoader
182 */
183 public static FlavorMap getDefaultFlavorMap() {
184 AppContext context = AppContext.getAppContext();
185 FlavorMap fm = (FlavorMap) context.get(FLAVOR_MAP_KEY);
186 if (fm == null) {
187 fm = new SystemFlavorMap();
188 context.put(FLAVOR_MAP_KEY, fm);
189 }
190 return fm;
191 }
192
193 private SystemFlavorMap() {
194 }
195
196 /**
197 * Initializes a SystemFlavorMap by reading flavormap.properties and
198 * AWT.DnD.flavorMapFileURL.
199 * For thread-safety must be called under lock on this.
200 */
201 private void initSystemFlavorMap() {
202 if (isMapInitialized) {
203 return;
204 }
205
206 isMapInitialized = true;
207 BufferedReader flavormapDotProperties =
208 java.security.AccessController.doPrivileged(
209 new java.security.PrivilegedAction<BufferedReader>() {
210 public BufferedReader run() {
211 String fileName =
212 System.getProperty("java.home") +
213 File.separator +
214 "lib" +
215 File.separator +
216 "flavormap.properties";
217 try {
218 return new BufferedReader
219 (new InputStreamReader
220 (new File(fileName).toURI().toURL().openStream(), "ISO-8859-1"));
221 } catch (MalformedURLException e) {
222 System.err.println("MalformedURLException:" + e + " while loading default flavormap.properties file:" + fileName);
223 } catch (IOException e) {
224 System.err.println("IOException:" + e + " while loading default flavormap.properties file:" + fileName);
225 }
226 return null;
227 }
228 });
229
230 String url =
231 java.security.AccessController.doPrivileged(
232 new java.security.PrivilegedAction<String>() {
233 public String run() {
234 return Toolkit.getProperty("AWT.DnD.flavorMapFileURL", null);
235 }
236 });
237
238 if (flavormapDotProperties != null) {
239 try {
240 parseAndStoreReader(flavormapDotProperties);
241 } catch (IOException e) {
242 System.err.println("IOException:" + e + " while parsing default flavormap.properties file");
243 }
244 }
245
246 BufferedReader flavormapURL = null;
247 if (url != null) {
248 try {
249 flavormapURL = new BufferedReader(new InputStreamReader(new URL(url).openStream(), "ISO-8859-1"));
250 } catch (MalformedURLException e) {
251 System.err.println("MalformedURLException:" + e + " while reading AWT.DnD.flavorMapFileURL:" + url);
252 } catch (IOException e) {
253 System.err.println("IOException:" + e + " while reading AWT.DnD.flavorMapFileURL:" + url);
254 } catch (SecurityException e) {
255 // ignored
256 }
257 }
258
259 if (flavormapURL != null) {
260 try {
261 parseAndStoreReader(flavormapURL);
262 } catch (IOException e) {
263 System.err.println("IOException:" + e + " while parsing AWT.DnD.flavorMapFileURL");
264 }
265 }
266 }
267 /**
268 * Copied code from java.util.Properties. Parsing the data ourselves is the
269 * only way to handle duplicate keys and values.
270 */
271 private void parseAndStoreReader(BufferedReader in) throws IOException {
272 while (true) {
273 // Get next line
274 String line = in.readLine();
275 if (line == null) {
276 return;
277 }
278
279 if (line.length() > 0) {
280 // Continue lines that end in slashes if they are not comments
281 char firstChar = line.charAt(0);
282 if (firstChar != '#' && firstChar != '!') {
283 while (continueLine(line)) {
284 String nextLine = in.readLine();
285 if (nextLine == null) {
286 nextLine = "";
287 }
288 String loppedLine =
289 line.substring(0, line.length() - 1);
290 // Advance beyond whitespace on new line
291 int startIndex = 0;
292 for(; startIndex < nextLine.length(); startIndex++) {
293 if (whiteSpaceChars.
294 indexOf(nextLine.charAt(startIndex)) == -1)
295 {
296 break;
297 }
298 }
299 nextLine = nextLine.substring(startIndex,
300 nextLine.length());
301 line = loppedLine+nextLine;
302 }
303
304 // Find start of key
305 int len = line.length();
306 int keyStart = 0;
307 for(; keyStart < len; keyStart++) {
308 if(whiteSpaceChars.
309 indexOf(line.charAt(keyStart)) == -1) {
310 break;
311 }
312 }
313
314 // Blank lines are ignored
315 if (keyStart == len) {
316 continue;
317 }
318
319 // Find separation between key and value
320 int separatorIndex = keyStart;
321 for(; separatorIndex < len; separatorIndex++) {
322 char currentChar = line.charAt(separatorIndex);
323 if (currentChar == '\\') {
324 separatorIndex++;
325 } else if (keyValueSeparators.
326 indexOf(currentChar) != -1) {
327 break;
328 }
329 }
330
331 // Skip over whitespace after key if any
332 int valueIndex = separatorIndex;
333 for (; valueIndex < len; valueIndex++) {
334 if (whiteSpaceChars.
335 indexOf(line.charAt(valueIndex)) == -1) {
336 break;
337 }
338 }
339
340 // Skip over one non whitespace key value separators if any
341 if (valueIndex < len) {
342 if (strictKeyValueSeparators.
343 indexOf(line.charAt(valueIndex)) != -1) {
344 valueIndex++;
345 }
346 }
347
348 // Skip over white space after other separators if any
349 while (valueIndex < len) {
350 if (whiteSpaceChars.
351 indexOf(line.charAt(valueIndex)) == -1) {
352 break;
353 }
354 valueIndex++;
355 }
356
357 String key = line.substring(keyStart, separatorIndex);
358 String value = (separatorIndex < len)
359 ? line.substring(valueIndex, len)
360 : "";
361
362 // Convert then store key and value
363 key = loadConvert(key);
364 value = loadConvert(value);
365
366 try {
367 MimeType mime = new MimeType(value);
368 if ("text".equals(mime.getPrimaryType())) {
369 String charset = mime.getParameter("charset");
370 if (DataTransferer.doesSubtypeSupportCharset
371 (mime.getSubType(), charset))
372 {
373 // We need to store the charset and eoln
374 // parameters, if any, so that the
375 // DataTransferer will have this information
376 // for conversion into the native format.
377 DataTransferer transferer =
378 DataTransferer.getInstance();
379 if (transferer != null) {
380 transferer.registerTextFlavorProperties
381 (key, charset,
382 mime.getParameter("eoln"),
383 mime.getParameter("terminators"));
384 }
385 }
386
387 // But don't store any of these parameters in the
388 // DataFlavor itself for any text natives (even
389 // non-charset ones). The SystemFlavorMap will
390 // synthesize the appropriate mappings later.
391 mime.removeParameter("charset");
392 mime.removeParameter("class");
393 mime.removeParameter("eoln");
394 mime.removeParameter("terminators");
395 value = mime.toString();
396 }
397 } catch (MimeTypeParseException e) {
398 e.printStackTrace();
399 continue;
400 }
401
402 DataFlavor flavor;
403 try {
404 flavor = new DataFlavor(value);
405 } catch (Exception e) {
406 try {
407 flavor = new DataFlavor(value, (String)null);
408 } catch (Exception ee) {
409 ee.printStackTrace();
410 continue;
411 }
412 }
413
414 final LinkedHashSet<DataFlavor> dfs = new LinkedHashSet<>();
415
416 dfs.add(flavor);
417
418 if ("text".equals(flavor.getPrimaryType())) {
419 dfs.addAll(convertMimeTypeToDataFlavors(value));
420 }
421
422 for (DataFlavor df : dfs) {
423 store(df, key, getFlavorToNative());
424 store(key, df, getNativeToFlavor());
425 }
426 }
427 }
428 }
429 }
430
431 /**
432 * Copied from java.util.Properties.
433 */
434 private boolean continueLine (String line) {
435 int slashCount = 0;
436 int index = line.length() - 1;
437 while((index >= 0) && (line.charAt(index--) == '\\')) {
438 slashCount++;
439 }
440 return (slashCount % 2 == 1);
441 }
442
443 /**
444 * Copied from java.util.Properties.
445 */
446 private String loadConvert(String theString) {
447 char aChar;
448 int len = theString.length();
449 StringBuilder outBuffer = new StringBuilder(len);
450
451 for (int x = 0; x < len; ) {
452 aChar = theString.charAt(x++);
453 if (aChar == '\\') {
454 aChar = theString.charAt(x++);
455 if (aChar == 'u') {
456 // Read the xxxx
457 int value = 0;
458 for (int i = 0; i < 4; i++) {
459 aChar = theString.charAt(x++);
460 switch (aChar) {
461 case '0': case '1': case '2': case '3': case '4':
462 case '5': case '6': case '7': case '8': case '9': {
463 value = (value << 4) + aChar - '0';
464 break;
465 }
466 case 'a': case 'b': case 'c':
467 case 'd': case 'e': case 'f': {
468 value = (value << 4) + 10 + aChar - 'a';
469 break;
470 }
471 case 'A': case 'B': case 'C':
472 case 'D': case 'E': case 'F': {
473 value = (value << 4) + 10 + aChar - 'A';
474 break;
475 }
476 default: {
477 throw new IllegalArgumentException(
478 "Malformed \\uxxxx encoding.");
479 }
480 }
481 }
482 outBuffer.append((char)value);
483 } else {
484 if (aChar == 't') {
485 aChar = '\t';
486 } else if (aChar == 'r') {
487 aChar = '\r';
488 } else if (aChar == 'n') {
489 aChar = '\n';
490 } else if (aChar == 'f') {
491 aChar = '\f';
492 }
493 outBuffer.append(aChar);
494 }
495 } else {
496 outBuffer.append(aChar);
497 }
498 }
499 return outBuffer.toString();
500 }
501
502 /**
503 * Stores the listed object under the specified hash key in map. Unlike a
504 * standard map, the listed object will not replace any object already at
505 * the appropriate Map location, but rather will be appended to a List
506 * stored in that location.
507 */
508 private <H, L> void store(H hashed, L listed, Map<H, List<L>> map) {
509 List<L> list = map.get(hashed);
510 if (list == null) {
511 list = new ArrayList<>(1);
512 map.put(hashed, list);
513 }
514 if (!list.contains(listed)) {
515 list.add(listed);
516 }
517 }
518
519 /**
520 * Semantically equivalent to 'nativeToFlavor.get(nat)'. This method
521 * handles the case where 'nat' is not found in 'nativeToFlavor'. In that
522 * case, a new DataFlavor is synthesized, stored, and returned, if and
523 * only if the specified native is encoded as a Java MIME type.
524 */
525 private List<DataFlavor> nativeToFlavorLookup(String nat) {
526 List<DataFlavor> flavors = getNativeToFlavor().get(nat);
527
528 if (nat != null && !disabledMappingGenerationKeys.contains(nat)) {
529 DataTransferer transferer = DataTransferer.getInstance();
530 if (transferer != null) {
531 List<DataFlavor> platformFlavors =
532 transferer.getPlatformMappingsForNative(nat);
533 if (!platformFlavors.isEmpty()) {
534 if (flavors != null) {
535 platformFlavors.removeAll(new HashSet<>(flavors));
536 // Prepending the platform-specific mappings ensures
537 // that the flavors added with
538 // addFlavorForUnencodedNative() are at the end of
539 // list.
540 platformFlavors.addAll(flavors);
541 }
542 flavors = platformFlavors;
543 }
544 }
545 }
546
547 if (flavors == null && isJavaMIMEType(nat)) {
548 String decoded = decodeJavaMIMEType(nat);
549 DataFlavor flavor = null;
550
551 try {
552 flavor = new DataFlavor(decoded);
553 } catch (Exception e) {
554 System.err.println("Exception \"" + e.getClass().getName() +
555 ": " + e.getMessage() +
556 "\"while constructing DataFlavor for: " +
557 decoded);
558 }
559
560 if (flavor != null) {
561 flavors = new ArrayList<>(1);
562 getNativeToFlavor().put(nat, flavors);
563 flavors.add(flavor);
564 getFlavorsForNativeCache.remove(nat);
565 getFlavorsForNativeCache.remove(null);
566
567 List<String> natives = getFlavorToNative().get(flavor);
568 if (natives == null) {
569 natives = new ArrayList<>(1);
570 getFlavorToNative().put(flavor, natives);
571 }
572 natives.add(nat);
573 getNativesForFlavorCache.remove(flavor);
574 getNativesForFlavorCache.remove(null);
575 }
576 }
577
578 return (flavors != null) ? flavors : new ArrayList<>(0);
579 }
580
581 /**
582 * Semantically equivalent to 'flavorToNative.get(flav)'. This method
583 * handles the case where 'flav' is not found in 'flavorToNative' depending
584 * on the value of passes 'synthesize' parameter. If 'synthesize' is
585 * SYNTHESIZE_IF_NOT_FOUND a native is synthesized, stored, and returned by
586 * encoding the DataFlavor's MIME type. Otherwise an empty List is returned
587 * and 'flavorToNative' remains unaffected.
588 */
589 private List<String> flavorToNativeLookup(final DataFlavor flav,
590 final boolean synthesize) {
591 List<String> natives = getFlavorToNative().get(flav);
592
593 if (flav != null && !disabledMappingGenerationKeys.contains(flav)) {
594 DataTransferer transferer = DataTransferer.getInstance();
595 if (transferer != null) {
596 List<String> platformNatives =
597 transferer.getPlatformMappingsForFlavor(flav);
598 if (!platformNatives.isEmpty()) {
599 if (natives != null) {
600 platformNatives.removeAll(new HashSet<>(natives));
601 // Prepend the platform-specific mappings to ensure
602 // that the natives added with
603 // addUnencodedNativeForFlavor() are at the end of
604 // list.
605 platformNatives.addAll(natives);
606 }
607 natives = platformNatives;
608 }
609 }
610 }
611
612 if (natives == null) {
613 if (synthesize) {
614 String encoded = encodeDataFlavor(flav);
615 natives = new ArrayList<>(1);
616 getFlavorToNative().put(flav, natives);
617 natives.add(encoded);
618 getNativesForFlavorCache.remove(flav);
619 getNativesForFlavorCache.remove(null);
620
621 List<DataFlavor> flavors = getNativeToFlavor().get(encoded);
622 if (flavors == null) {
623 flavors = new ArrayList<>(1);
624 getNativeToFlavor().put(encoded, flavors);
625 }
626 flavors.add(flav);
627 getFlavorsForNativeCache.remove(encoded);
628 getFlavorsForNativeCache.remove(null);
629 } else {
630 natives = new ArrayList<>(0);
631 }
632 }
633
634 return natives;
635 }
636
637 /**
638 * Returns a <code>List</code> of <code>String</code> natives to which the
639 * specified <code>DataFlavor</code> can be translated by the data transfer
640 * subsystem. The <code>List</code> will be sorted from best native to
641 * worst. That is, the first native will best reflect data in the specified
642 * flavor to the underlying native platform.
643 * <p>
644 * If the specified <code>DataFlavor</code> is previously unknown to the
645 * data transfer subsystem and the data transfer subsystem is unable to
646 * translate this <code>DataFlavor</code> to any existing native, then
647 * invoking this method will establish a
648 * mapping in both directions between the specified <code>DataFlavor</code>
649 * and an encoded version of its MIME type as its native.
650 *
651 * @param flav the <code>DataFlavor</code> whose corresponding natives
652 * should be returned. If <code>null</code> is specified, all
653 * natives currently known to the data transfer subsystem are
654 * returned in a non-deterministic order.
655 * @return a <code>java.util.List</code> of <code>java.lang.String</code>
656 * objects which are platform-specific representations of platform-
657 * specific data formats
658 *
659 * @see #encodeDataFlavor
660 * @since 1.4
661 */
662 public synchronized List<String> getNativesForFlavor(DataFlavor flav) {
663 List<String> retval = null;
664
665 // Check cache, even for null flav
666 SoftReference<List<String>> ref = getNativesForFlavorCache.get(flav);
667 if (ref != null) {
668 retval = ref.get();
669 if (retval != null) {
670 // Create a copy, because client code can modify the returned
671 // list.
672 return new ArrayList<>(retval);
673 }
674 }
675
676 if (flav == null) {
677 retval = new ArrayList<>(getNativeToFlavor().keySet());
678 } else if (disabledMappingGenerationKeys.contains(flav)) {
679 // In this case we shouldn't synthesize a native for this flavor,
680 // since its mappings were explicitly specified.
681 retval = flavorToNativeLookup(flav, !SYNTHESIZE_IF_NOT_FOUND);
682 } else if (DataTransferer.isFlavorCharsetTextType(flav)) {
683
684 // For text/* flavors, flavor-to-native mappings specified in
685 // flavormap.properties are stored per flavor's base type.
686 if ("text".equals(flav.getPrimaryType())) {
687 retval = getAllNativesForType(flav.mimeType.getBaseType());
688 if (retval != null) {
689 // To prevent the List stored in the map from modification.
690 retval = new ArrayList(retval);
691 }
692 }
693
694 // Also include text/plain natives, but don't duplicate Strings
695 List<String> textPlainList = getAllNativesForType(TEXT_PLAIN_BASE_TYPE);
696
697 if (textPlainList != null && !textPlainList.isEmpty()) {
698 // To prevent the List stored in the map from modification.
699 // This also guarantees that removeAll() is supported.
700 textPlainList = new ArrayList<>(textPlainList);
701 if (retval != null && !retval.isEmpty()) {
702 // Use HashSet to get constant-time performance for search.
703 textPlainList.removeAll(new HashSet<>(retval));
704 retval.addAll(textPlainList);
705 } else {
706 retval = textPlainList;
707 }
708 }
709
710 if (retval == null || retval.isEmpty()) {
711 retval = flavorToNativeLookup(flav, SYNTHESIZE_IF_NOT_FOUND);
712 } else {
713 // In this branch it is guaranteed that natives explicitly
714 // listed for flav's MIME type were added with
715 // addUnencodedNativeForFlavor(), so they have lower priority.
716 List<String> explicitList =
717 flavorToNativeLookup(flav, !SYNTHESIZE_IF_NOT_FOUND);
718
719 // flavorToNativeLookup() never returns null.
720 // It can return an empty List, however.
721 if (!explicitList.isEmpty()) {
722 // To prevent the List stored in the map from modification.
723 // This also guarantees that removeAll() is supported.
724 explicitList = new ArrayList<>(explicitList);
725 // Use HashSet to get constant-time performance for search.
726 explicitList.removeAll(new HashSet<>(retval));
727 retval.addAll(explicitList);
728 }
729 }
730 } else if (DataTransferer.isFlavorNoncharsetTextType(flav)) {
731 retval = getAllNativesForType(flav.mimeType.getBaseType());
732
733 if (retval == null || retval.isEmpty()) {
734 retval = flavorToNativeLookup(flav, SYNTHESIZE_IF_NOT_FOUND);
735 } else {
736 // In this branch it is guaranteed that natives explicitly
737 // listed for flav's MIME type were added with
738 // addUnencodedNativeForFlavor(), so they have lower priority.
739 List<String> explicitList =
740 flavorToNativeLookup(flav, !SYNTHESIZE_IF_NOT_FOUND);
741
742 // flavorToNativeLookup() never returns null.
743 // It can return an empty List, however.
744 if (!explicitList.isEmpty()) {
745 // To prevent the List stored in the map from modification.
746 // This also guarantees that add/removeAll() are supported.
747 retval = new ArrayList<>(retval);
748 explicitList = new ArrayList<>(explicitList);
749 // Use HashSet to get constant-time performance for search.
750 explicitList.removeAll(new HashSet<>(retval));
751 retval.addAll(explicitList);
752 }
753 }
754 } else {
755 retval = flavorToNativeLookup(flav, SYNTHESIZE_IF_NOT_FOUND);
756 }
757
758 getNativesForFlavorCache.put(flav, new SoftReference<>(retval));
759 // Create a copy, because client code can modify the returned list.
760 return new ArrayList<>(retval);
761 }
762
763 /**
764 * Returns a <code>List</code> of <code>DataFlavor</code>s to which the
765 * specified <code>String</code> native can be translated by the data
766 * transfer subsystem. The <code>List</code> will be sorted from best
767 * <code>DataFlavor</code> to worst. That is, the first
768 * <code>DataFlavor</code> will best reflect data in the specified
769 * native to a Java application.
770 * <p>
771 * If the specified native is previously unknown to the data transfer
772 * subsystem, and that native has been properly encoded, then invoking this
773 * method will establish a mapping in both directions between the specified
774 * native and a <code>DataFlavor</code> whose MIME type is a decoded
775 * version of the native.
776 * <p>
777 * If the specified native is not a properly encoded native and the
778 * mappings for this native have not been altered with
779 * <code>setFlavorsForNative</code>, then the contents of the
780 * <code>List</code> is platform dependent, but <code>null</code>
781 * cannot be returned.
782 *
783 * @param nat the native whose corresponding <code>DataFlavor</code>s
784 * should be returned. If <code>null</code> is specified, all
785 * <code>DataFlavor</code>s currently known to the data transfer
786 * subsystem are returned in a non-deterministic order.
787 * @return a <code>java.util.List</code> of <code>DataFlavor</code>
788 * objects into which platform-specific data in the specified,
789 * platform-specific native can be translated
790 *
791 * @see #encodeJavaMIMEType
792 * @since 1.4
793 */
794 public synchronized List<DataFlavor> getFlavorsForNative(String nat) {
795
796 // Check cache, even for null nat
797 SoftReference<List<DataFlavor>> ref = getFlavorsForNativeCache.get(nat);
798 if (ref != null) {
799 List<DataFlavor> retval = ref.get();
800 if (retval != null) {
801 return new ArrayList<>(retval);
802 }
803 }
804
805 final LinkedHashSet <DataFlavor> returnValue =
806 new LinkedHashSet<>();
807
808 if (nat == null) {
809 final List<String> natives = getNativesForFlavor(null);
810
811 for (String n : natives)
812 {
813 final List<DataFlavor> flavors = getFlavorsForNative(n);
814
815 for (DataFlavor df : flavors)
816 {
817 returnValue.add(df);
818 }
819 }
820 } else {
821
822 final List<DataFlavor> flavors = nativeToFlavorLookup(nat);
823
824 if (disabledMappingGenerationKeys.contains(nat)) {
825 return flavors;
826 }
827
828 final List<DataFlavor> flavorsAndBaseTypes =
829 nativeToFlavorLookup(nat);
830
831 for (DataFlavor df : flavorsAndBaseTypes) {
832 returnValue.add(df);
833 if ("text".equals(df.getPrimaryType())) {
834 try {
835 returnValue.addAll(
836 convertMimeTypeToDataFlavors(
837 new MimeType(df.getMimeType()
838 ).getBaseType()));
839 } catch (MimeTypeParseException e) {
840 e.printStackTrace();
841 }
842 }
843 }
844
845 }
846
847 final List<DataFlavor> arrayList = new ArrayList<>(returnValue);
848 getFlavorsForNativeCache.put(nat, new SoftReference<>(arrayList));
849 return new ArrayList<>(arrayList);
850 }
851
852 private static Set<DataFlavor> convertMimeTypeToDataFlavors(
853 final String baseType) {
854
855 final Set<DataFlavor> returnValue = new LinkedHashSet<>();
856
857 String subType = null;
858
859 try {
860 final MimeType mimeType = new MimeType(baseType);
861 subType = mimeType.getSubType();
862 } catch (MimeTypeParseException mtpe) {
863 // Cannot happen, since we checked all mappings
864 // on load from flavormap.properties.
865 assert(false);
866 }
867
868 if (DataTransferer.doesSubtypeSupportCharset(subType, null)) {
869 if (TEXT_PLAIN_BASE_TYPE.equals(baseType))
870 {
871 returnValue.add(DataFlavor.stringFlavor);
872 }
873
874 for (String unicodeClassName : UNICODE_TEXT_CLASSES) {
875 final String mimeType = baseType + ";charset=Unicode;class=" +
876 unicodeClassName;
877
878 final LinkedHashSet<String> mimeTypes =
879 handleHtmlMimeTypes(baseType, mimeType);
880 for (String mt : mimeTypes) {
881 DataFlavor toAdd = null;
882 try {
883 toAdd = new DataFlavor(mt);
884 } catch (ClassNotFoundException cannotHappen) {
885 }
886 returnValue.add(toAdd);
887 }
888 }
889
890 for (String charset : DataTransferer.standardEncodings()) {
891
892 for (String encodedTextClass : ENCODED_TEXT_CLASSES) {
893 final String mimeType =
894 baseType + ";charset=" + charset +
895 ";class=" + encodedTextClass;
896
897 final LinkedHashSet<String> mimeTypes =
898 handleHtmlMimeTypes(baseType, mimeType);
899
900 for (String mt : mimeTypes) {
901
902 DataFlavor df = null;
903
904 try {
905 df = new DataFlavor(mt);
906 // Check for equality to plainTextFlavor so
907 // that we can ensure that the exact charset of
908 // plainTextFlavor, not the canonical charset
909 // or another equivalent charset with a
910 // different name, is used.
911 if (df.equals(DataFlavor.plainTextFlavor)) {
912 df = DataFlavor.plainTextFlavor;
913 }
914 } catch (ClassNotFoundException cannotHappen) {
915 }
916
917 returnValue.add(df);
918 }
919 }
920 }
921
922 if (TEXT_PLAIN_BASE_TYPE.equals(baseType))
923 {
924 returnValue.add(DataFlavor.plainTextFlavor);
925 }
926 } else {
927 // Non-charset text natives should be treated as
928 // opaque, 8-bit data in any of its various
929 // representations.
930 for (String encodedTextClassName : ENCODED_TEXT_CLASSES) {
931 DataFlavor toAdd = null;
932 try {
933 toAdd = new DataFlavor(baseType +
934 ";class=" + encodedTextClassName);
935 } catch (ClassNotFoundException cannotHappen) {
936 }
937 returnValue.add(toAdd);
938 }
939 }
940 return returnValue;
941 }
942
943 private static final String [] htmlDocumntTypes =
944 new String [] {"all", "selection", "fragment"};
945
946 private static LinkedHashSet<String> handleHtmlMimeTypes(
947 String baseType, String mimeType) {
948
949 LinkedHashSet<String> returnValues = new LinkedHashSet<>();
950
951 if (HTML_TEXT_BASE_TYPE.equals(baseType)) {
952 for (String documentType : htmlDocumntTypes) {
953 returnValues.add(mimeType + ";document=" + documentType);
954 }
955 } else {
956 returnValues.add(mimeType);
957 }
958
959 return returnValues;
960 }
961
962 /**
963 * Returns a <code>Map</code> of the specified <code>DataFlavor</code>s to
964 * their most preferred <code>String</code> native. Each native value will
965 * be the same as the first native in the List returned by
966 * <code>getNativesForFlavor</code> for the specified flavor.
967 * <p>
968 * If a specified <code>DataFlavor</code> is previously unknown to the
969 * data transfer subsystem, then invoking this method will establish a
970 * mapping in both directions between the specified <code>DataFlavor</code>
971 * and an encoded version of its MIME type as its native.
972 *
973 * @param flavors an array of <code>DataFlavor</code>s which will be the
974 * key set of the returned <code>Map</code>. If <code>null</code> is
975 * specified, a mapping of all <code>DataFlavor</code>s known to the
976 * data transfer subsystem to their most preferred
977 * <code>String</code> natives will be returned.
978 * @return a <code>java.util.Map</code> of <code>DataFlavor</code>s to
979 * <code>String</code> natives
980 *
981 * @see #getNativesForFlavor
982 * @see #encodeDataFlavor
983 */
984 public synchronized Map<DataFlavor,String>
985 getNativesForFlavors(DataFlavor[] flavors)
986 {
987 // Use getNativesForFlavor to generate extra natives for text flavors
988 // and stringFlavor
989
990 if (flavors == null) {
991 List flavor_list = getFlavorsForNative(null);
992 flavors = new DataFlavor[flavor_list.size()];
993 flavor_list.toArray(flavors);
994 }
995
996 Map<DataFlavor, String> retval = new HashMap<>(flavors.length, 1.0f);
997 for (DataFlavor flavor : flavors) {
998 List<String> natives = getNativesForFlavor(flavor);
999 String nat = (natives.isEmpty()) ? null : natives.get(0);
1000 retval.put(flavor, nat);
1001 }
1002
1003 return retval;
1004 }
1005
1006 /**
1007 * Returns a <code>Map</code> of the specified <code>String</code> natives
1008 * to their most preferred <code>DataFlavor</code>. Each
1009 * <code>DataFlavor</code> value will be the same as the first
1010 * <code>DataFlavor</code> in the List returned by
1011 * <code>getFlavorsForNative</code> for the specified native.
1012 * <p>
1013 * If a specified native is previously unknown to the data transfer
1014 * subsystem, and that native has been properly encoded, then invoking this
1015 * method will establish a mapping in both directions between the specified
1016 * native and a <code>DataFlavor</code> whose MIME type is a decoded
1017 * version of the native.
1018 *
1019 * @param natives an array of <code>String</code>s which will be the
1020 * key set of the returned <code>Map</code>. If <code>null</code> is
1021 * specified, a mapping of all supported <code>String</code> natives
1022 * to their most preferred <code>DataFlavor</code>s will be
1023 * returned.
1024 * @return a <code>java.util.Map</code> of <code>String</code> natives to
1025 * <code>DataFlavor</code>s
1026 *
1027 * @see #getFlavorsForNative
1028 * @see #encodeJavaMIMEType
1029 */
1030 public synchronized Map<String,DataFlavor>
1031 getFlavorsForNatives(String[] natives)
1032 {
1033 // Use getFlavorsForNative to generate extra flavors for text natives
1034
1035 if (natives == null) {
1036 List native_list = getNativesForFlavor(null);
1037 natives = new String[native_list.size()];
1038 native_list.toArray(natives);
1039 }
1040
1041 Map<String, DataFlavor> retval = new HashMap<>(natives.length, 1.0f);
1042 for (String aNative : natives) {
1043 List<DataFlavor> flavors = getFlavorsForNative(aNative);
1044 DataFlavor flav = (flavors.isEmpty())? null : flavors.get(0);
1045 retval.put(aNative, flav);
1046 }
1047
1048 return retval;
1049 }
1050
1051 /**
1052 * Adds a mapping from the specified <code>DataFlavor</code> (and all
1053 * <code>DataFlavor</code>s equal to the specified <code>DataFlavor</code>)
1054 * to the specified <code>String</code> native.
1055 * Unlike <code>getNativesForFlavor</code>, the mapping will only be
1056 * established in one direction, and the native will not be encoded. To
1057 * establish a two-way mapping, call
1058 * <code>addFlavorForUnencodedNative</code> as well. The new mapping will
1059 * be of lower priority than any existing mapping.
1060 * This method has no effect if a mapping from the specified or equal
1061 * <code>DataFlavor</code> to the specified <code>String</code> native
1062 * already exists.
1063 *
1064 * @param flav the <code>DataFlavor</code> key for the mapping
1065 * @param nat the <code>String</code> native value for the mapping
1066 * @throws NullPointerException if flav or nat is <code>null</code>
1067 *
1068 * @see #addFlavorForUnencodedNative
1069 * @since 1.4
1070 */
1071 public synchronized void addUnencodedNativeForFlavor(DataFlavor flav,
1072 String nat) {
1073 if (flav == null || nat == null) {
1074 throw new NullPointerException("null arguments not permitted");
1075 }
1076
1077 List<String> natives = getFlavorToNative().get(flav);
1078 if (natives == null) {
1079 natives = new ArrayList<>(1);
1080 getFlavorToNative().put(flav, natives);
1081 } else if (natives.contains(nat)) {
1082 return;
1083 }
1084 natives.add(nat);
1085 getNativesForFlavorCache.remove(flav);
1086 getNativesForFlavorCache.remove(null);
1087 }
1088
1089 /**
1090 * Discards the current mappings for the specified <code>DataFlavor</code>
1091 * and all <code>DataFlavor</code>s equal to the specified
1092 * <code>DataFlavor</code>, and creates new mappings to the
1093 * specified <code>String</code> natives.
1094 * Unlike <code>getNativesForFlavor</code>, the mappings will only be
1095 * established in one direction, and the natives will not be encoded. To
1096 * establish two-way mappings, call <code>setFlavorsForNative</code>
1097 * as well. The first native in the array will represent the highest
1098 * priority mapping. Subsequent natives will represent mappings of
1099 * decreasing priority.
1100 * <p>
1101 * If the array contains several elements that reference equal
1102 * <code>String</code> natives, this method will establish new mappings
1103 * for the first of those elements and ignore the rest of them.
1104 * <p>
1105 * It is recommended that client code not reset mappings established by the
1106 * data transfer subsystem. This method should only be used for
1107 * application-level mappings.
1108 *
1109 * @param flav the <code>DataFlavor</code> key for the mappings
1110 * @param natives the <code>String</code> native values for the mappings
1111 * @throws NullPointerException if flav or natives is <code>null</code>
1112 * or if natives contains <code>null</code> elements
1113 *
1114 * @see #setFlavorsForNative
1115 * @since 1.4
1116 */
1117 public synchronized void setNativesForFlavor(DataFlavor flav,
1118 String[] natives) {
1119 if (flav == null || natives == null) {
1120 throw new NullPointerException("null arguments not permitted");
1121 }
1122
1123 getFlavorToNative().remove(flav);
1124 for (String aNative : natives) {
1125 addUnencodedNativeForFlavor(flav, aNative);
1126 }
1127 disabledMappingGenerationKeys.add(flav);
1128 // Clear the cache to handle the case of empty natives.
1129 getNativesForFlavorCache.remove(flav);
1130 getNativesForFlavorCache.remove(null);
1131 }
1132
1133 /**
1134 * Adds a mapping from a single <code>String</code> native to a single
1135 * <code>DataFlavor</code>. Unlike <code>getFlavorsForNative</code>, the
1136 * mapping will only be established in one direction, and the native will
1137 * not be encoded. To establish a two-way mapping, call
1138 * <code>addUnencodedNativeForFlavor</code> as well. The new mapping will
1139 * be of lower priority than any existing mapping.
1140 * This method has no effect if a mapping from the specified
1141 * <code>String</code> native to the specified or equal
1142 * <code>DataFlavor</code> already exists.
1143 *
1144 * @param nat the <code>String</code> native key for the mapping
1145 * @param flav the <code>DataFlavor</code> value for the mapping
1146 * @throws NullPointerException if nat or flav is <code>null</code>
1147 *
1148 * @see #addUnencodedNativeForFlavor
1149 * @since 1.4
1150 */
1151 public synchronized void addFlavorForUnencodedNative(String nat,
1152 DataFlavor flav) {
1153 if (nat == null || flav == null) {
1154 throw new NullPointerException("null arguments not permitted");
1155 }
1156
1157 List<DataFlavor> flavors = getNativeToFlavor().get(nat);
1158 if (flavors == null) {
1159 flavors = new ArrayList<>(1);
1160 getNativeToFlavor().put(nat, flavors);
1161 } else if (flavors.contains(flav)) {
1162 return;
1163 }
1164 flavors.add(flav);
1165 getFlavorsForNativeCache.remove(nat);
1166 getFlavorsForNativeCache.remove(null);
1167 }
1168
1169 /**
1170 * Discards the current mappings for the specified <code>String</code>
1171 * native, and creates new mappings to the specified
1172 * <code>DataFlavor</code>s. Unlike <code>getFlavorsForNative</code>, the
1173 * mappings will only be established in one direction, and the natives need
1174 * not be encoded. To establish two-way mappings, call
1175 * <code>setNativesForFlavor</code> as well. The first
1176 * <code>DataFlavor</code> in the array will represent the highest priority
1177 * mapping. Subsequent <code>DataFlavor</code>s will represent mappings of
1178 * decreasing priority.
1179 * <p>
1180 * If the array contains several elements that reference equal
1181 * <code>DataFlavor</code>s, this method will establish new mappings
1182 * for the first of those elements and ignore the rest of them.
1183 * <p>
1184 * It is recommended that client code not reset mappings established by the
1185 * data transfer subsystem. This method should only be used for
1186 * application-level mappings.
1187 *
1188 * @param nat the <code>String</code> native key for the mappings
1189 * @param flavors the <code>DataFlavor</code> values for the mappings
1190 * @throws NullPointerException if nat or flavors is <code>null</code>
1191 * or if flavors contains <code>null</code> elements
1192 *
1193 * @see #setNativesForFlavor
1194 * @since 1.4
1195 */
1196 public synchronized void setFlavorsForNative(String nat,
1197 DataFlavor[] flavors) {
1198 if (nat == null || flavors == null) {
1199 throw new NullPointerException("null arguments not permitted");
1200 }
1201
1202 getNativeToFlavor().remove(nat);
1203 for (DataFlavor flavor : flavors) {
1204 addFlavorForUnencodedNative(nat, flavor);
1205 }
1206 disabledMappingGenerationKeys.add(nat);
1207 // Clear the cache to handle the case of empty flavors.
1208 getFlavorsForNativeCache.remove(nat);
1209 getFlavorsForNativeCache.remove(null);
1210 }
1211
1212 /**
1213 * Encodes a MIME type for use as a <code>String</code> native. The format
1214 * of an encoded representation of a MIME type is implementation-dependent.
1215 * The only restrictions are:
1216 * <ul>
1217 * <li>The encoded representation is <code>null</code> if and only if the
1218 * MIME type <code>String</code> is <code>null</code>.</li>
1219 * <li>The encoded representations for two non-<code>null</code> MIME type
1220 * <code>String</code>s are equal if and only if these <code>String</code>s
1221 * are equal according to <code>String.equals(Object)</code>.</li>
1222 * </ul>
1223 * <p>
1224 * The reference implementation of this method returns the specified MIME
1225 * type <code>String</code> prefixed with <code>JAVA_DATAFLAVOR:</code>.
1226 *
1227 * @param mimeType the MIME type to encode
1228 * @return the encoded <code>String</code>, or <code>null</code> if
1229 * mimeType is <code>null</code>
1230 */
1231 public static String encodeJavaMIMEType(String mimeType) {
1232 return (mimeType != null)
1233 ? JavaMIME + mimeType
1234 : null;
1235 }
1236
1237 /**
1238 * Encodes a <code>DataFlavor</code> for use as a <code>String</code>
1239 * native. The format of an encoded <code>DataFlavor</code> is
1240 * implementation-dependent. The only restrictions are:
1241 * <ul>
1242 * <li>The encoded representation is <code>null</code> if and only if the
1243 * specified <code>DataFlavor</code> is <code>null</code> or its MIME type
1244 * <code>String</code> is <code>null</code>.</li>
1245 * <li>The encoded representations for two non-<code>null</code>
1246 * <code>DataFlavor</code>s with non-<code>null</code> MIME type
1247 * <code>String</code>s are equal if and only if the MIME type
1248 * <code>String</code>s of these <code>DataFlavor</code>s are equal
1249 * according to <code>String.equals(Object)</code>.</li>
1250 * </ul>
1251 * <p>
1252 * The reference implementation of this method returns the MIME type
1253 * <code>String</code> of the specified <code>DataFlavor</code> prefixed
1254 * with <code>JAVA_DATAFLAVOR:</code>.
1255 *
1256 * @param flav the <code>DataFlavor</code> to encode
1257 * @return the encoded <code>String</code>, or <code>null</code> if
1258 * flav is <code>null</code> or has a <code>null</code> MIME type
1259 */
1260 public static String encodeDataFlavor(DataFlavor flav) {
1261 return (flav != null)
1262 ? SystemFlavorMap.encodeJavaMIMEType(flav.getMimeType())
1263 : null;
1264 }
1265
1266 /**
1267 * Returns whether the specified <code>String</code> is an encoded Java
1268 * MIME type.
1269 *
1270 * @param str the <code>String</code> to test
1271 * @return <code>true</code> if the <code>String</code> is encoded;
1272 * <code>false</code> otherwise
1273 */
1274 public static boolean isJavaMIMEType(String str) {
1275 return (str != null && str.startsWith(JavaMIME, 0));
1276 }
1277
1278 /**
1279 * Decodes a <code>String</code> native for use as a Java MIME type.
1280 *
1281 * @param nat the <code>String</code> to decode
1282 * @return the decoded Java MIME type, or <code>null</code> if nat is not
1283 * an encoded <code>String</code> native
1284 */
1285 public static String decodeJavaMIMEType(String nat) {
1286 return (isJavaMIMEType(nat))
1287 ? nat.substring(JavaMIME.length(), nat.length()).trim()
1288 : null;
1289 }
1290
1291 /**
1292 * Decodes a <code>String</code> native for use as a
1293 * <code>DataFlavor</code>.
1294 *
1295 * @param nat the <code>String</code> to decode
1296 * @return the decoded <code>DataFlavor</code>, or <code>null</code> if
1297 * nat is not an encoded <code>String</code> native
1298 * @throws ClassNotFoundException if the class of the data flavor
1299 * is not loaded
1300 */
1301 public static DataFlavor decodeDataFlavor(String nat)
1302 throws ClassNotFoundException
1303 {
1304 String retval_str = SystemFlavorMap.decodeJavaMIMEType(nat);
1305 return (retval_str != null)
1306 ? new DataFlavor(retval_str)
1307 : null;
1308 }
1309
1310 private List<String> getAllNativesForType(String type) {
1311 Set<String> retval = null;
1312 for (DataFlavor dataFlavor : convertMimeTypeToDataFlavors(type)) {
1313 List<String> natives = getFlavorToNative().get(dataFlavor);
1314 if (natives != null && !natives.isEmpty()) {
1315 if (retval == null) {
1316 retval = new LinkedHashSet<>();
1317 }
1318 retval.addAll(natives);
1319 }
1320 }
1321 return retval == null ? null : new ArrayList<>(retval);
1322 }
1323 }