1 /* 2 * Copyright (c) 1996, 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 sun.awt.datatransfer.DataTransferer; 29 import sun.reflect.misc.ReflectUtil; 30 31 import java.io.ByteArrayInputStream; 32 import java.io.CharArrayReader; 33 import java.io.Externalizable; 34 import java.io.IOException; 35 import java.io.InputStream; 36 import java.io.InputStreamReader; 37 import java.io.ObjectInput; 38 import java.io.ObjectOutput; 39 import java.io.OptionalDataException; 40 import java.io.Reader; 41 import java.io.StringReader; 42 import java.io.UnsupportedEncodingException; 43 import java.nio.ByteBuffer; 44 import java.nio.CharBuffer; 45 import java.util.Arrays; 46 import java.util.Collections; 47 import java.util.Comparator; 48 import java.util.Objects; 49 50 import static sun.security.util.SecurityConstants.GET_CLASSLOADER_PERMISSION; 51 52 /** 53 * A {@code DataFlavor} provides meta information about data. {@code DataFlavor} 54 * is typically used to access data on the clipboard, or during 55 * a drag and drop operation. 56 * <p> 57 * An instance of {@code DataFlavor} encapsulates a content type as 58 * defined in <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045</a> 59 * and <a href="http://www.ietf.org/rfc/rfc2046.txt">RFC 2046</a>. 60 * A content type is typically referred to as a MIME type. 61 * <p> 62 * A content type consists of a media type (referred 63 * to as the primary type), a subtype, and optional parameters. See 64 * <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045</a> 65 * for details on the syntax of a MIME type. 66 * <p> 67 * The JRE data transfer implementation interprets the parameter "class" 68 * of a MIME type as <B>a representation class</b>. 69 * The representation class reflects the class of the object being 70 * transferred. In other words, the representation class is the type of 71 * object returned by {@link Transferable#getTransferData}. 72 * For example, the MIME type of {@link #imageFlavor} is 73 * {@code "image/x-java-image;class=java.awt.Image"}, 74 * the primary type is {@code image}, the subtype is 75 * {@code x-java-image}, and the representation class is 76 * {@code java.awt.Image}. When {@code getTransferData} is invoked 77 * with a {@code DataFlavor} of {@code imageFlavor}, an instance of 78 * {@code java.awt.Image} is returned. 79 * It's important to note that {@code DataFlavor} does no error checking 80 * against the representation class. It is up to consumers of 81 * {@code DataFlavor}, such as {@code Transferable}, to honor the representation 82 * class. 83 * <br> 84 * Note, if you do not specify a representation class when 85 * creating a {@code DataFlavor}, the default 86 * representation class is used. See appropriate documentation for 87 * {@code DataFlavor}'s constructors. 88 * <p> 89 * Also, {@code DataFlavor} instances with the "text" primary 90 * MIME type may have a "charset" parameter. Refer to 91 * <a href="http://www.ietf.org/rfc/rfc2046.txt">RFC 2046</a> and 92 * {@link #selectBestTextFlavor} for details on "text" MIME types 93 * and the "charset" parameter. 94 * <p> 95 * Equality of {@code DataFlavors} is determined by the primary type, 96 * subtype, and representation class. Refer to {@link #equals(DataFlavor)} for 97 * details. When determining equality, any optional parameters are ignored. 98 * For example, the following produces two {@code DataFlavors} that 99 * are considered identical: 100 * <pre> 101 * DataFlavor flavor1 = new DataFlavor(Object.class, "X-test/test; class=<java.lang.Object>; foo=bar"); 102 * DataFlavor flavor2 = new DataFlavor(Object.class, "X-test/test; class=<java.lang.Object>; x=y"); 103 * // The following returns true. 104 * flavor1.equals(flavor2); 105 * </pre> 106 * As mentioned, {@code flavor1} and {@code flavor2} are considered identical. 107 * As such, asking a {@code Transferable} for either {@code DataFlavor} returns 108 * the same results. 109 * <p> 110 * For more information on the using data transfer with Swing see 111 * the <a href="https://docs.oracle.com/javase/tutorial/uiswing/dnd/index.html"> 112 * How to Use Drag and Drop and Data Transfer</a>, 113 * section in <em>Java Tutorial</em>. 114 * 115 * @author Blake Sullivan 116 * @author Laurence P. G. Cable 117 * @author Jeff Dunn 118 */ 119 public class DataFlavor implements Externalizable, Cloneable { 120 121 private static final long serialVersionUID = 8367026044764648243L; 122 private static final Class<InputStream> ioInputStreamClass = InputStream.class; 123 124 /** 125 * Tries to load a class from: the bootstrap loader, the system loader, 126 * the context loader (if one is present) and finally the loader specified. 127 * 128 * @param className the name of the class to be loaded 129 * @param fallback the fallback loader 130 * @return the class loaded 131 * @exception ClassNotFoundException if class is not found 132 */ 133 protected final static Class<?> tryToLoadClass(String className, 134 ClassLoader fallback) 135 throws ClassNotFoundException 136 { 137 ReflectUtil.checkPackageAccess(className); 138 try { 139 SecurityManager sm = System.getSecurityManager(); 140 if (sm != null) { 141 sm.checkPermission(GET_CLASSLOADER_PERMISSION); 142 } 143 ClassLoader loader = ClassLoader.getSystemClassLoader(); 144 try { 145 // bootstrap class loader and system class loader if present 146 return Class.forName(className, true, loader); 147 } 148 catch (ClassNotFoundException exception) { 149 // thread context class loader if and only if present 150 loader = Thread.currentThread().getContextClassLoader(); 151 if (loader != null) { 152 try { 153 return Class.forName(className, true, loader); 154 } 155 catch (ClassNotFoundException e) { 156 // fallback to user's class loader 157 } 158 } 159 } 160 } catch (SecurityException exception) { 161 // ignore secured class loaders 162 } 163 return Class.forName(className, true, fallback); 164 } 165 166 /* 167 * private initializer 168 */ 169 static private DataFlavor createConstant(Class<?> rc, String prn) { 170 try { 171 return new DataFlavor(rc, prn); 172 } catch (Exception e) { 173 return null; 174 } 175 } 176 177 /* 178 * private initializer 179 */ 180 static private DataFlavor createConstant(String mt, String prn) { 181 try { 182 return new DataFlavor(mt, prn); 183 } catch (Exception e) { 184 return null; 185 } 186 } 187 188 /* 189 * private initializer 190 */ 191 static private DataFlavor initHtmlDataFlavor(String htmlFlavorType) { 192 try { 193 return new DataFlavor ("text/html; class=java.lang.String;document=" + 194 htmlFlavorType + ";charset=Unicode"); 195 } catch (Exception e) { 196 return null; 197 } 198 } 199 200 /** 201 * The <code>DataFlavor</code> representing a Java Unicode String class, 202 * where: 203 * <pre> 204 * representationClass = java.lang.String 205 * mimeType = "application/x-java-serialized-object" 206 * </pre> 207 */ 208 public static final DataFlavor stringFlavor = createConstant(java.lang.String.class, "Unicode String"); 209 210 /** 211 * The <code>DataFlavor</code> representing a Java Image class, 212 * where: 213 * <pre> 214 * representationClass = java.awt.Image 215 * mimeType = "image/x-java-image" 216 * </pre> 217 */ 218 public static final DataFlavor imageFlavor = createConstant("image/x-java-image; class=java.awt.Image", "Image"); 219 220 /** 221 * The <code>DataFlavor</code> representing plain text with Unicode 222 * encoding, where: 223 * <pre> 224 * representationClass = InputStream 225 * mimeType = "text/plain; charset=unicode" 226 * </pre> 227 * This <code>DataFlavor</code> has been <b>deprecated</b> because 228 * (1) Its representation is an InputStream, an 8-bit based representation, 229 * while Unicode is a 16-bit character set; and (2) The charset "unicode" 230 * is not well-defined. "unicode" implies a particular platform's 231 * implementation of Unicode, not a cross-platform implementation. 232 * 233 * @deprecated as of 1.3. Use <code>DataFlavor.getReaderForText(Transferable)</code> 234 * instead of <code>Transferable.getTransferData(DataFlavor.plainTextFlavor)</code>. 235 */ 236 @Deprecated 237 public static final DataFlavor plainTextFlavor = createConstant("text/plain; charset=unicode; class=java.io.InputStream", "Plain Text"); 238 239 /** 240 * A MIME Content-Type of application/x-java-serialized-object represents 241 * a graph of Java object(s) that have been made persistent. 242 * 243 * The representation class associated with this <code>DataFlavor</code> 244 * identifies the Java type of an object returned as a reference 245 * from an invocation <code>java.awt.datatransfer.getTransferData</code>. 246 */ 247 public static final String javaSerializedObjectMimeType = "application/x-java-serialized-object"; 248 249 /** 250 * To transfer a list of files to/from Java (and the underlying 251 * platform) a <code>DataFlavor</code> of this type/subtype and 252 * representation class of <code>java.util.List</code> is used. 253 * Each element of the list is required/guaranteed to be of type 254 * <code>java.io.File</code>. 255 */ 256 public static final DataFlavor javaFileListFlavor = createConstant("application/x-java-file-list;class=java.util.List", null); 257 258 /** 259 * To transfer a reference to an arbitrary Java object reference that 260 * has no associated MIME Content-type, across a <code>Transferable</code> 261 * interface WITHIN THE SAME JVM, a <code>DataFlavor</code> 262 * with this type/subtype is used, with a <code>representationClass</code> 263 * equal to the type of the class/interface being passed across the 264 * <code>Transferable</code>. 265 * <p> 266 * The object reference returned from 267 * <code>Transferable.getTransferData</code> for a <code>DataFlavor</code> 268 * with this MIME Content-Type is required to be 269 * an instance of the representation Class of the <code>DataFlavor</code>. 270 */ 271 public static final String javaJVMLocalObjectMimeType = "application/x-java-jvm-local-objectref"; 272 273 /** 274 * In order to pass a live link to a Remote object via a Drag and Drop 275 * <code>ACTION_LINK</code> operation a Mime Content Type of 276 * application/x-java-remote-object should be used, 277 * where the representation class of the <code>DataFlavor</code> 278 * represents the type of the <code>Remote</code> interface to be 279 * transferred. 280 */ 281 public static final String javaRemoteObjectMimeType = "application/x-java-remote-object"; 282 283 /** 284 * Represents a piece of an HTML markup. The markup consists of the part 285 * selected on the source side. Therefore some tags in the markup may be 286 * unpaired. If the flavor is used to represent the data in 287 * a {@link Transferable} instance, no additional changes will be made. 288 * This DataFlavor instance represents the same HTML markup as DataFlavor 289 * instances which content MIME type does not contain document parameter 290 * and representation class is the String class. 291 * <pre> 292 * representationClass = String 293 * mimeType = "text/html" 294 * </pre> 295 */ 296 public static DataFlavor selectionHtmlFlavor = initHtmlDataFlavor("selection"); 297 298 /** 299 * Represents a piece of an HTML markup. If possible, the markup received 300 * from a native system is supplemented with pair tags to be 301 * a well-formed HTML markup. If the flavor is used to represent the data in 302 * a {@link Transferable} instance, no additional changes will be made. 303 * <pre> 304 * representationClass = String 305 * mimeType = "text/html" 306 * </pre> 307 */ 308 public static DataFlavor fragmentHtmlFlavor = initHtmlDataFlavor("fragment"); 309 310 /** 311 * Represents a piece of an HTML markup. If possible, the markup 312 * received from a native system is supplemented with additional 313 * tags to make up a well-formed HTML document. If the flavor is used to 314 * represent the data in a {@link Transferable} instance, 315 * no additional changes will be made. 316 * <pre> 317 * representationClass = String 318 * mimeType = "text/html" 319 * </pre> 320 */ 321 public static DataFlavor allHtmlFlavor = initHtmlDataFlavor("all"); 322 323 /** 324 * Constructs a new <code>DataFlavor</code>. This constructor is 325 * provided only for the purpose of supporting the 326 * <code>Externalizable</code> interface. It is not 327 * intended for public (client) use. 328 * 329 * @since 1.2 330 */ 331 public DataFlavor() { 332 super(); 333 } 334 335 /** 336 * Constructs a fully specified <code>DataFlavor</code>. 337 * 338 * @exception NullPointerException if either <code>primaryType</code>, 339 * <code>subType</code> or <code>representationClass</code> is null 340 */ 341 private DataFlavor(String primaryType, String subType, MimeTypeParameterList params, Class<?> representationClass, String humanPresentableName) { 342 super(); 343 if (primaryType == null) { 344 throw new NullPointerException("primaryType"); 345 } 346 if (subType == null) { 347 throw new NullPointerException("subType"); 348 } 349 if (representationClass == null) { 350 throw new NullPointerException("representationClass"); 351 } 352 353 if (params == null) params = new MimeTypeParameterList(); 354 355 params.set("class", representationClass.getName()); 356 357 if (humanPresentableName == null) { 358 humanPresentableName = params.get("humanPresentableName"); 359 360 if (humanPresentableName == null) 361 humanPresentableName = primaryType + "/" + subType; 362 } 363 364 try { 365 mimeType = new MimeType(primaryType, subType, params); 366 } catch (MimeTypeParseException mtpe) { 367 throw new IllegalArgumentException("MimeType Parse Exception: " + mtpe.getMessage()); 368 } 369 370 this.representationClass = representationClass; 371 this.humanPresentableName = humanPresentableName; 372 373 mimeType.removeParameter("humanPresentableName"); 374 } 375 376 /** 377 * Constructs a <code>DataFlavor</code> that represents a Java class. 378 * <p> 379 * The returned <code>DataFlavor</code> will have the following 380 * characteristics: 381 * <pre> 382 * representationClass = representationClass 383 * mimeType = application/x-java-serialized-object 384 * </pre> 385 * @param representationClass the class used to transfer data in this flavor 386 * @param humanPresentableName the human-readable string used to identify 387 * this flavor; if this parameter is <code>null</code> 388 * then the value of the the MIME Content Type is used 389 * @exception NullPointerException if <code>representationClass</code> is null 390 */ 391 public DataFlavor(Class<?> representationClass, String humanPresentableName) { 392 this("application", "x-java-serialized-object", null, representationClass, humanPresentableName); 393 if (representationClass == null) { 394 throw new NullPointerException("representationClass"); 395 } 396 } 397 398 /** 399 * Constructs a <code>DataFlavor</code> that represents a 400 * <code>MimeType</code>. 401 * <p> 402 * The returned <code>DataFlavor</code> will have the following 403 * characteristics: 404 * <p> 405 * If the <code>mimeType</code> is 406 * "application/x-java-serialized-object; class=<representation class>", 407 * the result is the same as calling 408 * <code>new DataFlavor(Class:forName(<representation class>)</code>. 409 * <p> 410 * Otherwise: 411 * <pre> 412 * representationClass = InputStream 413 * mimeType = mimeType 414 * </pre> 415 * @param mimeType the string used to identify the MIME type for this flavor; 416 * if the the <code>mimeType</code> does not specify a 417 * "class=" parameter, or if the class is not successfully 418 * loaded, then an <code>IllegalArgumentException</code> 419 * is thrown 420 * @param humanPresentableName the human-readable string used to identify 421 * this flavor; if this parameter is <code>null</code> 422 * then the value of the the MIME Content Type is used 423 * @exception IllegalArgumentException if <code>mimeType</code> is 424 * invalid or if the class is not successfully loaded 425 * @exception NullPointerException if <code>mimeType</code> is null 426 */ 427 public DataFlavor(String mimeType, String humanPresentableName) { 428 super(); 429 if (mimeType == null) { 430 throw new NullPointerException("mimeType"); 431 } 432 try { 433 initialize(mimeType, humanPresentableName, this.getClass().getClassLoader()); 434 } catch (MimeTypeParseException mtpe) { 435 throw new IllegalArgumentException("failed to parse:" + mimeType); 436 } catch (ClassNotFoundException cnfe) { 437 throw new IllegalArgumentException("can't find specified class: " + cnfe.getMessage()); 438 } 439 } 440 441 /** 442 * Constructs a <code>DataFlavor</code> that represents a 443 * <code>MimeType</code>. 444 * <p> 445 * The returned <code>DataFlavor</code> will have the following 446 * characteristics: 447 * <p> 448 * If the mimeType is 449 * "application/x-java-serialized-object; class=<representation class>", 450 * the result is the same as calling 451 * <code>new DataFlavor(Class:forName(<representation class>)</code>. 452 * <p> 453 * Otherwise: 454 * <pre> 455 * representationClass = InputStream 456 * mimeType = mimeType 457 * </pre> 458 * @param mimeType the string used to identify the MIME type for this flavor 459 * @param humanPresentableName the human-readable string used to 460 * identify this flavor 461 * @param classLoader the class loader to use 462 * @exception ClassNotFoundException if the class is not loaded 463 * @exception IllegalArgumentException if <code>mimeType</code> is 464 * invalid 465 * @exception NullPointerException if <code>mimeType</code> is null 466 */ 467 public DataFlavor(String mimeType, String humanPresentableName, ClassLoader classLoader) throws ClassNotFoundException { 468 super(); 469 if (mimeType == null) { 470 throw new NullPointerException("mimeType"); 471 } 472 try { 473 initialize(mimeType, humanPresentableName, classLoader); 474 } catch (MimeTypeParseException mtpe) { 475 throw new IllegalArgumentException("failed to parse:" + mimeType); 476 } 477 } 478 479 /** 480 * Constructs a <code>DataFlavor</code> from a <code>mimeType</code> string. 481 * The string can specify a "class=<fully specified Java class name>" 482 * parameter to create a <code>DataFlavor</code> with the desired 483 * representation class. If the string does not contain "class=" parameter, 484 * <code>java.io.InputStream</code> is used as default. 485 * 486 * @param mimeType the string used to identify the MIME type for this flavor; 487 * if the class specified by "class=" parameter is not 488 * successfully loaded, then an 489 * <code>ClassNotFoundException</code> is thrown 490 * @exception ClassNotFoundException if the class is not loaded 491 * @exception IllegalArgumentException if <code>mimeType</code> is 492 * invalid 493 * @exception NullPointerException if <code>mimeType</code> is null 494 */ 495 public DataFlavor(String mimeType) throws ClassNotFoundException { 496 super(); 497 if (mimeType == null) { 498 throw new NullPointerException("mimeType"); 499 } 500 try { 501 initialize(mimeType, null, this.getClass().getClassLoader()); 502 } catch (MimeTypeParseException mtpe) { 503 throw new IllegalArgumentException("failed to parse:" + mimeType); 504 } 505 } 506 507 /** 508 * Common initialization code called from various constructors. 509 * 510 * @param mimeType the MIME Content Type (must have a class= param) 511 * @param humanPresentableName the human Presentable Name or 512 * <code>null</code> 513 * @param classLoader the fallback class loader to resolve against 514 * 515 * @throws MimeTypeParseException 516 * @throws ClassNotFoundException 517 * @throws NullPointerException if <code>mimeType</code> is null 518 * 519 * @see #tryToLoadClass 520 */ 521 private void initialize(String mimeType, String humanPresentableName, ClassLoader classLoader) throws MimeTypeParseException, ClassNotFoundException { 522 if (mimeType == null) { 523 throw new NullPointerException("mimeType"); 524 } 525 526 this.mimeType = new MimeType(mimeType); // throws 527 528 String rcn = getParameter("class"); 529 530 if (rcn == null) { 531 if ("application/x-java-serialized-object".equals(this.mimeType.getBaseType())) 532 533 throw new IllegalArgumentException("no representation class specified for:" + mimeType); 534 else 535 representationClass = java.io.InputStream.class; // default 536 } else { // got a class name 537 representationClass = DataFlavor.tryToLoadClass(rcn, classLoader); 538 } 539 540 this.mimeType.setParameter("class", representationClass.getName()); 541 542 if (humanPresentableName == null) { 543 humanPresentableName = this.mimeType.getParameter("humanPresentableName"); 544 if (humanPresentableName == null) 545 humanPresentableName = this.mimeType.getPrimaryType() + "/" + this.mimeType.getSubType(); 546 } 547 548 this.humanPresentableName = humanPresentableName; // set it. 549 550 this.mimeType.removeParameter("humanPresentableName"); // just in case 551 } 552 553 /** 554 * String representation of this <code>DataFlavor</code> and its 555 * parameters. The resulting <code>String</code> contains the name of 556 * the <code>DataFlavor</code> class, this flavor's MIME type, and its 557 * representation class. If this flavor has a primary MIME type of "text", 558 * supports the charset parameter, and has an encoded representation, the 559 * flavor's charset is also included. See <code>selectBestTextFlavor</code> 560 * for a list of text flavors which support the charset parameter. 561 * 562 * @return string representation of this <code>DataFlavor</code> 563 * @see #selectBestTextFlavor 564 */ 565 public String toString() { 566 String string = getClass().getName(); 567 string += "["+paramString()+"]"; 568 return string; 569 } 570 571 private String paramString() { 572 String params = ""; 573 params += "mimetype="; 574 if (mimeType == null) { 575 params += "null"; 576 } else { 577 params += mimeType.getBaseType(); 578 } 579 params += ";representationclass="; 580 if (representationClass == null) { 581 params += "null"; 582 } else { 583 params += representationClass.getName(); 584 } 585 if (DataTransferer.isFlavorCharsetTextType(this) && 586 (isRepresentationClassInputStream() || 587 isRepresentationClassByteBuffer() || 588 byte[].class.equals(representationClass))) 589 { 590 params += ";charset=" + DataTransferer.getTextCharset(this); 591 } 592 return params; 593 } 594 595 /** 596 * Returns a <code>DataFlavor</code> representing plain text with Unicode 597 * encoding, where: 598 * <pre> 599 * representationClass = java.io.InputStream 600 * mimeType = "text/plain; 601 * charset=<platform default Unicode encoding>" 602 * </pre> 603 * Sun's implementation for Microsoft Windows uses the encoding <code>utf-16le</code>. 604 * Sun's implementation for Solaris and Linux uses the encoding 605 * <code>iso-10646-ucs-2</code>. 606 * 607 * @return a <code>DataFlavor</code> representing plain text 608 * with Unicode encoding 609 * @since 1.3 610 */ 611 public static final DataFlavor getTextPlainUnicodeFlavor() { 612 String encoding = null; 613 DataTransferer transferer = DataTransferer.getInstance(); 614 if (transferer != null) { 615 encoding = transferer.getDefaultUnicodeEncoding(); 616 } 617 return new DataFlavor( 618 "text/plain;charset="+encoding 619 +";class=java.io.InputStream", "Plain Text"); 620 } 621 622 /** 623 * Selects the best text <code>DataFlavor</code> from an array of <code> 624 * DataFlavor</code>s. Only <code>DataFlavor.stringFlavor</code>, and 625 * equivalent flavors, and flavors that have a primary MIME type of "text", 626 * are considered for selection. 627 * <p> 628 * Flavors are first sorted by their MIME types in the following order: 629 * <ul> 630 * <li>"text/sgml" 631 * <li>"text/xml" 632 * <li>"text/html" 633 * <li>"text/rtf" 634 * <li>"text/enriched" 635 * <li>"text/richtext" 636 * <li>"text/uri-list" 637 * <li>"text/tab-separated-values" 638 * <li>"text/t140" 639 * <li>"text/rfc822-headers" 640 * <li>"text/parityfec" 641 * <li>"text/directory" 642 * <li>"text/css" 643 * <li>"text/calendar" 644 * <li>"application/x-java-serialized-object" 645 * <li>"text/plain" 646 * <li>"text/<other>" 647 * </ul> 648 * <p>For example, "text/sgml" will be selected over 649 * "text/html", and <code>DataFlavor.stringFlavor</code> will be chosen 650 * over <code>DataFlavor.plainTextFlavor</code>. 651 * <p> 652 * If two or more flavors share the best MIME type in the array, then that 653 * MIME type will be checked to see if it supports the charset parameter. 654 * <p> 655 * The following MIME types support, or are treated as though they support, 656 * the charset parameter: 657 * <ul> 658 * <li>"text/sgml" 659 * <li>"text/xml" 660 * <li>"text/html" 661 * <li>"text/enriched" 662 * <li>"text/richtext" 663 * <li>"text/uri-list" 664 * <li>"text/directory" 665 * <li>"text/css" 666 * <li>"text/calendar" 667 * <li>"application/x-java-serialized-object" 668 * <li>"text/plain" 669 * </ul> 670 * The following MIME types do not support, or are treated as though they 671 * do not support, the charset parameter: 672 * <ul> 673 * <li>"text/rtf" 674 * <li>"text/tab-separated-values" 675 * <li>"text/t140" 676 * <li>"text/rfc822-headers" 677 * <li>"text/parityfec" 678 * </ul> 679 * For "text/<other>" MIME types, the first time the JRE needs to 680 * determine whether the MIME type supports the charset parameter, it will 681 * check whether the parameter is explicitly listed in an arbitrarily 682 * chosen <code>DataFlavor</code> which uses that MIME type. If so, the JRE 683 * will assume from that point on that the MIME type supports the charset 684 * parameter and will not check again. If the parameter is not explicitly 685 * listed, the JRE will assume from that point on that the MIME type does 686 * not support the charset parameter and will not check again. Because 687 * this check is performed on an arbitrarily chosen 688 * <code>DataFlavor</code>, developers must ensure that all 689 * <code>DataFlavor</code>s with a "text/<other>" MIME type specify 690 * the charset parameter if it is supported by that MIME type. Developers 691 * should never rely on the JRE to substitute the platform's default 692 * charset for a "text/<other>" DataFlavor. Failure to adhere to this 693 * restriction will lead to undefined behavior. 694 * <p> 695 * If the best MIME type in the array does not support the charset 696 * parameter, the flavors which share that MIME type will then be sorted by 697 * their representation classes in the following order: 698 * <code>java.io.InputStream</code>, <code>java.nio.ByteBuffer</code>, 699 * <code>[B</code>, <all others>. 700 * <p> 701 * If two or more flavors share the best representation class, or if no 702 * flavor has one of the three specified representations, then one of those 703 * flavors will be chosen non-deterministically. 704 * <p> 705 * If the best MIME type in the array does support the charset parameter, 706 * the flavors which share that MIME type will then be sorted by their 707 * representation classes in the following order: 708 * <code>java.io.Reader</code>, <code>java.lang.String</code>, 709 * <code>java.nio.CharBuffer</code>, <code>[C</code>, <all others>. 710 * <p> 711 * If two or more flavors share the best representation class, and that 712 * representation is one of the four explicitly listed, then one of those 713 * flavors will be chosen non-deterministically. If, however, no flavor has 714 * one of the four specified representations, the flavors will then be 715 * sorted by their charsets. Unicode charsets, such as "UTF-16", "UTF-8", 716 * "UTF-16BE", "UTF-16LE", and their aliases, are considered best. After 717 * them, the platform default charset and its aliases are selected. 718 * "US-ASCII" and its aliases are worst. All other charsets are chosen in 719 * alphabetical order, but only charsets supported by this implementation 720 * of the Java platform will be considered. 721 * <p> 722 * If two or more flavors share the best charset, the flavors will then 723 * again be sorted by their representation classes in the following order: 724 * <code>java.io.InputStream</code>, <code>java.nio.ByteBuffer</code>, 725 * <code>[B</code>, <all others>. 726 * <p> 727 * If two or more flavors share the best representation class, or if no 728 * flavor has one of the three specified representations, then one of those 729 * flavors will be chosen non-deterministically. 730 * 731 * @param availableFlavors an array of available <code>DataFlavor</code>s 732 * @return the best (highest fidelity) flavor according to the rules 733 * specified above, or <code>null</code>, 734 * if <code>availableFlavors</code> is <code>null</code>, 735 * has zero length, or contains no text flavors 736 * @since 1.3 737 */ 738 public static final DataFlavor selectBestTextFlavor( 739 DataFlavor[] availableFlavors) { 740 if (availableFlavors == null || availableFlavors.length == 0) { 741 return null; 742 } 743 744 if (textFlavorComparator == null) { 745 textFlavorComparator = new TextFlavorComparator(); 746 } 747 748 DataFlavor bestFlavor = 749 (DataFlavor)Collections.max(Arrays.asList(availableFlavors), 750 textFlavorComparator); 751 752 if (!bestFlavor.isFlavorTextType()) { 753 return null; 754 } 755 756 return bestFlavor; 757 } 758 759 private static Comparator<DataFlavor> textFlavorComparator; 760 761 static class TextFlavorComparator 762 extends DataTransferer.DataFlavorComparator { 763 764 /** 765 * Compares two <code>DataFlavor</code> objects. Returns a negative 766 * integer, zero, or a positive integer as the first 767 * <code>DataFlavor</code> is worse than, equal to, or better than the 768 * second. 769 * <p> 770 * <code>DataFlavor</code>s are ordered according to the rules outlined 771 * for <code>selectBestTextFlavor</code>. 772 * 773 * @param obj1 the first <code>DataFlavor</code> to be compared 774 * @param obj2 the second <code>DataFlavor</code> to be compared 775 * @return a negative integer, zero, or a positive integer as the first 776 * argument is worse, equal to, or better than the second 777 * @throws ClassCastException if either of the arguments is not an 778 * instance of <code>DataFlavor</code> 779 * @throws NullPointerException if either of the arguments is 780 * <code>null</code> 781 * 782 * @see #selectBestTextFlavor 783 */ 784 public int compare(Object obj1, Object obj2) { 785 DataFlavor flavor1 = (DataFlavor)obj1; 786 DataFlavor flavor2 = (DataFlavor)obj2; 787 788 if (flavor1.isFlavorTextType()) { 789 if (flavor2.isFlavorTextType()) { 790 return super.compare(obj1, obj2); 791 } else { 792 return 1; 793 } 794 } else if (flavor2.isFlavorTextType()) { 795 return -1; 796 } else { 797 return 0; 798 } 799 } 800 } 801 802 /** 803 * Gets a Reader for a text flavor, decoded, if necessary, for the expected 804 * charset (encoding). The supported representation classes are 805 * <code>java.io.Reader</code>, <code>java.lang.String</code>, 806 * <code>java.nio.CharBuffer</code>, <code>[C</code>, 807 * <code>java.io.InputStream</code>, <code>java.nio.ByteBuffer</code>, 808 * and <code>[B</code>. 809 * <p> 810 * Because text flavors which do not support the charset parameter are 811 * encoded in a non-standard format, this method should not be called for 812 * such flavors. However, in order to maintain backward-compatibility, 813 * if this method is called for such a flavor, this method will treat the 814 * flavor as though it supports the charset parameter and attempt to 815 * decode it accordingly. See <code>selectBestTextFlavor</code> for a list 816 * of text flavors which do not support the charset parameter. 817 * 818 * @param transferable the <code>Transferable</code> whose data will be 819 * requested in this flavor 820 * 821 * @return a <code>Reader</code> to read the <code>Transferable</code>'s 822 * data 823 * 824 * @exception IllegalArgumentException if the representation class 825 * is not one of the seven listed above 826 * @exception IllegalArgumentException if the <code>Transferable</code> 827 * has <code>null</code> data 828 * @exception NullPointerException if the <code>Transferable</code> is 829 * <code>null</code> 830 * @exception UnsupportedEncodingException if this flavor's representation 831 * is <code>java.io.InputStream</code>, 832 * <code>java.nio.ByteBuffer</code>, or <code>[B</code> and 833 * this flavor's encoding is not supported by this 834 * implementation of the Java platform 835 * @exception UnsupportedFlavorException if the <code>Transferable</code> 836 * does not support this flavor 837 * @exception IOException if the data cannot be read because of an 838 * I/O error 839 * @see #selectBestTextFlavor 840 * @since 1.3 841 */ 842 public Reader getReaderForText(Transferable transferable) 843 throws UnsupportedFlavorException, IOException 844 { 845 Object transferObject = transferable.getTransferData(this); 846 if (transferObject == null) { 847 throw new IllegalArgumentException 848 ("getTransferData() returned null"); 849 } 850 851 if (transferObject instanceof Reader) { 852 return (Reader)transferObject; 853 } else if (transferObject instanceof String) { 854 return new StringReader((String)transferObject); 855 } else if (transferObject instanceof CharBuffer) { 856 CharBuffer buffer = (CharBuffer)transferObject; 857 int size = buffer.remaining(); 858 char[] chars = new char[size]; 859 buffer.get(chars, 0, size); 860 return new CharArrayReader(chars); 861 } else if (transferObject instanceof char[]) { 862 return new CharArrayReader((char[])transferObject); 863 } 864 865 InputStream stream = null; 866 867 if (transferObject instanceof InputStream) { 868 stream = (InputStream)transferObject; 869 } else if (transferObject instanceof ByteBuffer) { 870 ByteBuffer buffer = (ByteBuffer)transferObject; 871 int size = buffer.remaining(); 872 byte[] bytes = new byte[size]; 873 buffer.get(bytes, 0, size); 874 stream = new ByteArrayInputStream(bytes); 875 } else if (transferObject instanceof byte[]) { 876 stream = new ByteArrayInputStream((byte[])transferObject); 877 } 878 879 if (stream == null) { 880 throw new IllegalArgumentException("transfer data is not Reader, String, CharBuffer, char array, InputStream, ByteBuffer, or byte array"); 881 } 882 883 String encoding = getParameter("charset"); 884 return (encoding == null) 885 ? new InputStreamReader(stream) 886 : new InputStreamReader(stream, encoding); 887 } 888 889 /** 890 * Returns the MIME type string for this <code>DataFlavor</code>. 891 * @return the MIME type string for this flavor 892 */ 893 public String getMimeType() { 894 return (mimeType != null) ? mimeType.toString() : null; 895 } 896 897 /** 898 * Returns the <code>Class</code> which objects supporting this 899 * <code>DataFlavor</code> will return when this <code>DataFlavor</code> 900 * is requested. 901 * @return the <code>Class</code> which objects supporting this 902 * <code>DataFlavor</code> will return when this <code>DataFlavor</code> 903 * is requested 904 */ 905 public Class<?> getRepresentationClass() { 906 return representationClass; 907 } 908 909 /** 910 * Returns the human presentable name for the data format that this 911 * <code>DataFlavor</code> represents. This name would be localized 912 * for different countries. 913 * @return the human presentable name for the data format that this 914 * <code>DataFlavor</code> represents 915 */ 916 public String getHumanPresentableName() { 917 return humanPresentableName; 918 } 919 920 /** 921 * Returns the primary MIME type for this <code>DataFlavor</code>. 922 * @return the primary MIME type of this <code>DataFlavor</code> 923 */ 924 public String getPrimaryType() { 925 return (mimeType != null) ? mimeType.getPrimaryType() : null; 926 } 927 928 /** 929 * Returns the sub MIME type of this <code>DataFlavor</code>. 930 * @return the Sub MIME type of this <code>DataFlavor</code> 931 */ 932 public String getSubType() { 933 return (mimeType != null) ? mimeType.getSubType() : null; 934 } 935 936 /** 937 * Returns the human presentable name for this <code>DataFlavor</code> 938 * if <code>paramName</code> equals "humanPresentableName". Otherwise 939 * returns the MIME type value associated with <code>paramName</code>. 940 * 941 * @param paramName the parameter name requested 942 * @return the value of the name parameter, or <code>null</code> 943 * if there is no associated value 944 */ 945 public String getParameter(String paramName) { 946 if (paramName.equals("humanPresentableName")) { 947 return humanPresentableName; 948 } else { 949 return (mimeType != null) 950 ? mimeType.getParameter(paramName) : null; 951 } 952 } 953 954 /** 955 * Sets the human presentable name for the data format that this 956 * <code>DataFlavor</code> represents. This name would be localized 957 * for different countries. 958 * @param humanPresentableName the new human presentable name 959 */ 960 public void setHumanPresentableName(String humanPresentableName) { 961 this.humanPresentableName = humanPresentableName; 962 } 963 964 /** 965 * {@inheritDoc} 966 * <p> 967 * The equals comparison for the {@code DataFlavor} class is implemented 968 * as follows: Two <code>DataFlavor</code>s are considered equal if and 969 * only if their MIME primary type and subtype and representation class are 970 * equal. Additionally, if the primary type is "text", the subtype denotes 971 * a text flavor which supports the charset parameter, and the 972 * representation class is not <code>java.io.Reader</code>, 973 * <code>java.lang.String</code>, <code>java.nio.CharBuffer</code>, or 974 * <code>[C</code>, the <code>charset</code> parameter must also be equal. 975 * If a charset is not explicitly specified for one or both 976 * <code>DataFlavor</code>s, the platform default encoding is assumed. See 977 * <code>selectBestTextFlavor</code> for a list of text flavors which 978 * support the charset parameter. 979 * 980 * @param o the <code>Object</code> to compare with <code>this</code> 981 * @return <code>true</code> if <code>that</code> is equivalent to this 982 * <code>DataFlavor</code>; <code>false</code> otherwise 983 * @see #selectBestTextFlavor 984 */ 985 public boolean equals(Object o) { 986 return ((o instanceof DataFlavor) && equals((DataFlavor)o)); 987 } 988 989 /** 990 * This method has the same behavior as {@link #equals(Object)}. 991 * The only difference being that it takes a {@code DataFlavor} instance 992 * as a parameter. 993 * 994 * @param that the <code>DataFlavor</code> to compare with 995 * <code>this</code> 996 * @return <code>true</code> if <code>that</code> is equivalent to this 997 * <code>DataFlavor</code>; <code>false</code> otherwise 998 * @see #selectBestTextFlavor 999 */ 1000 public boolean equals(DataFlavor that) { 1001 if (that == null) { 1002 return false; 1003 } 1004 if (this == that) { 1005 return true; 1006 } 1007 1008 if (!Objects.equals(this.getRepresentationClass(), that.getRepresentationClass())) { 1009 return false; 1010 } 1011 1012 if (mimeType == null) { 1013 if (that.mimeType != null) { 1014 return false; 1015 } 1016 } else { 1017 if (!mimeType.match(that.mimeType)) { 1018 return false; 1019 } 1020 1021 if ("text".equals(getPrimaryType())) { 1022 if (DataTransferer.doesSubtypeSupportCharset(this) 1023 && representationClass != null 1024 && !isStandardTextRepresentationClass()) { 1025 String thisCharset = 1026 DataTransferer.canonicalName(this.getParameter("charset")); 1027 String thatCharset = 1028 DataTransferer.canonicalName(that.getParameter("charset")); 1029 if (!Objects.equals(thisCharset, thatCharset)) { 1030 return false; 1031 } 1032 } 1033 1034 if ("html".equals(getSubType())) { 1035 String thisDocument = this.getParameter("document"); 1036 String thatDocument = that.getParameter("document"); 1037 if (!Objects.equals(thisDocument, thatDocument)) { 1038 return false; 1039 } 1040 } 1041 } 1042 } 1043 1044 return true; 1045 } 1046 1047 /** 1048 * Compares only the <code>mimeType</code> against the passed in 1049 * <code>String</code> and <code>representationClass</code> is 1050 * not considered in the comparison. 1051 * 1052 * If <code>representationClass</code> needs to be compared, then 1053 * <code>equals(new DataFlavor(s))</code> may be used. 1054 * @deprecated As inconsistent with <code>hashCode()</code> contract, 1055 * use <code>isMimeTypeEqual(String)</code> instead. 1056 * @param s the {@code mimeType} to compare. 1057 * @return true if the String (MimeType) is equal; false otherwise or if 1058 * {@code s} is {@code null} 1059 */ 1060 @Deprecated 1061 public boolean equals(String s) { 1062 if (s == null || mimeType == null) 1063 return false; 1064 return isMimeTypeEqual(s); 1065 } 1066 1067 /** 1068 * Returns hash code for this <code>DataFlavor</code>. 1069 * For two equal <code>DataFlavor</code>s, hash codes are equal. 1070 * For the <code>String</code> 1071 * that matches <code>DataFlavor.equals(String)</code>, it is not 1072 * guaranteed that <code>DataFlavor</code>'s hash code is equal 1073 * to the hash code of the <code>String</code>. 1074 * 1075 * @return a hash code for this <code>DataFlavor</code> 1076 */ 1077 public int hashCode() { 1078 int total = 0; 1079 1080 if (representationClass != null) { 1081 total += representationClass.hashCode(); 1082 } 1083 1084 if (mimeType != null) { 1085 String primaryType = mimeType.getPrimaryType(); 1086 if (primaryType != null) { 1087 total += primaryType.hashCode(); 1088 } 1089 1090 // Do not add subType.hashCode() to the total. equals uses 1091 // MimeType.match which reports a match if one or both of the 1092 // subTypes is '*', regardless of the other subType. 1093 1094 if ("text".equals(primaryType)) { 1095 if (DataTransferer.doesSubtypeSupportCharset(this) 1096 && representationClass != null 1097 && !isStandardTextRepresentationClass()) { 1098 String charset = DataTransferer.canonicalName(getParameter("charset")); 1099 if (charset != null) { 1100 total += charset.hashCode(); 1101 } 1102 } 1103 1104 if ("html".equals(getSubType())) { 1105 String document = this.getParameter("document"); 1106 if (document != null) { 1107 total += document.hashCode(); 1108 } 1109 } 1110 } 1111 } 1112 1113 return total; 1114 } 1115 1116 /** 1117 * Identical to {@link #equals(DataFlavor)}. 1118 * 1119 * @param that the <code>DataFlavor</code> to compare with 1120 * <code>this</code> 1121 * @return <code>true</code> if <code>that</code> is equivalent to this 1122 * <code>DataFlavor</code>; <code>false</code> otherwise 1123 * @see #selectBestTextFlavor 1124 * @since 1.3 1125 */ 1126 public boolean match(DataFlavor that) { 1127 return equals(that); 1128 } 1129 1130 /** 1131 * Returns whether the string representation of the MIME type passed in 1132 * is equivalent to the MIME type of this <code>DataFlavor</code>. 1133 * Parameters are not included in the comparison. 1134 * 1135 * @param mimeType the string representation of the MIME type 1136 * @return true if the string representation of the MIME type passed in is 1137 * equivalent to the MIME type of this <code>DataFlavor</code>; 1138 * false otherwise 1139 * @throws NullPointerException if mimeType is <code>null</code> 1140 */ 1141 public boolean isMimeTypeEqual(String mimeType) { 1142 // JCK Test DataFlavor0117: if 'mimeType' is null, throw NPE 1143 if (mimeType == null) { 1144 throw new NullPointerException("mimeType"); 1145 } 1146 if (this.mimeType == null) { 1147 return false; 1148 } 1149 try { 1150 return this.mimeType.match(new MimeType(mimeType)); 1151 } catch (MimeTypeParseException mtpe) { 1152 return false; 1153 } 1154 } 1155 1156 /** 1157 * Compares the <code>mimeType</code> of two <code>DataFlavor</code> 1158 * objects. No parameters are considered. 1159 * 1160 * @param dataFlavor the <code>DataFlavor</code> to be compared 1161 * @return true if the <code>MimeType</code>s are equal, 1162 * otherwise false 1163 */ 1164 1165 public final boolean isMimeTypeEqual(DataFlavor dataFlavor) { 1166 return isMimeTypeEqual(dataFlavor.mimeType); 1167 } 1168 1169 /** 1170 * Compares the <code>mimeType</code> of two <code>DataFlavor</code> 1171 * objects. No parameters are considered. 1172 * 1173 * @return true if the <code>MimeType</code>s are equal, 1174 * otherwise false 1175 */ 1176 1177 private boolean isMimeTypeEqual(MimeType mtype) { 1178 if (this.mimeType == null) { 1179 return (mtype == null); 1180 } 1181 return mimeType.match(mtype); 1182 } 1183 1184 /** 1185 * Checks if the representation class is one of the standard text 1186 * representation classes. 1187 * 1188 * @return true if the representation class is one of the standard text 1189 * representation classes, otherwise false 1190 */ 1191 private boolean isStandardTextRepresentationClass() { 1192 return isRepresentationClassReader() 1193 || String.class.equals(representationClass) 1194 || isRepresentationClassCharBuffer() 1195 || char[].class.equals(representationClass); 1196 } 1197 1198 /** 1199 * Does the <code>DataFlavor</code> represent a serialized object? 1200 */ 1201 1202 public boolean isMimeTypeSerializedObject() { 1203 return isMimeTypeEqual(javaSerializedObjectMimeType); 1204 } 1205 1206 public final Class<?> getDefaultRepresentationClass() { 1207 return ioInputStreamClass; 1208 } 1209 1210 public final String getDefaultRepresentationClassAsString() { 1211 return getDefaultRepresentationClass().getName(); 1212 } 1213 1214 /** 1215 * Does the <code>DataFlavor</code> represent a 1216 * <code>java.io.InputStream</code>? 1217 */ 1218 1219 public boolean isRepresentationClassInputStream() { 1220 return ioInputStreamClass.isAssignableFrom(representationClass); 1221 } 1222 1223 /** 1224 * Returns whether the representation class for this 1225 * <code>DataFlavor</code> is <code>java.io.Reader</code> or a subclass 1226 * thereof. 1227 * 1228 * @since 1.4 1229 */ 1230 public boolean isRepresentationClassReader() { 1231 return java.io.Reader.class.isAssignableFrom(representationClass); 1232 } 1233 1234 /** 1235 * Returns whether the representation class for this 1236 * <code>DataFlavor</code> is <code>java.nio.CharBuffer</code> or a 1237 * subclass thereof. 1238 * 1239 * @since 1.4 1240 */ 1241 public boolean isRepresentationClassCharBuffer() { 1242 return java.nio.CharBuffer.class.isAssignableFrom(representationClass); 1243 } 1244 1245 /** 1246 * Returns whether the representation class for this 1247 * <code>DataFlavor</code> is <code>java.nio.ByteBuffer</code> or a 1248 * subclass thereof. 1249 * 1250 * @since 1.4 1251 */ 1252 public boolean isRepresentationClassByteBuffer() { 1253 return java.nio.ByteBuffer.class.isAssignableFrom(representationClass); 1254 } 1255 1256 /** 1257 * Returns true if the representation class can be serialized. 1258 * @return true if the representation class can be serialized 1259 */ 1260 1261 public boolean isRepresentationClassSerializable() { 1262 return java.io.Serializable.class.isAssignableFrom(representationClass); 1263 } 1264 1265 /** 1266 * Returns true if the representation class is <code>Remote</code>. 1267 * @return true if the representation class is <code>Remote</code> 1268 */ 1269 1270 public boolean isRepresentationClassRemote() { 1271 return DataTransferer.isRemote(representationClass); 1272 } 1273 1274 /** 1275 * Returns true if the <code>DataFlavor</code> specified represents 1276 * a serialized object. 1277 * @return true if the <code>DataFlavor</code> specified represents 1278 * a Serialized Object 1279 */ 1280 1281 public boolean isFlavorSerializedObjectType() { 1282 return isRepresentationClassSerializable() && isMimeTypeEqual(javaSerializedObjectMimeType); 1283 } 1284 1285 /** 1286 * Returns true if the <code>DataFlavor</code> specified represents 1287 * a remote object. 1288 * @return true if the <code>DataFlavor</code> specified represents 1289 * a Remote Object 1290 */ 1291 1292 public boolean isFlavorRemoteObjectType() { 1293 return isRepresentationClassRemote() 1294 && isRepresentationClassSerializable() 1295 && isMimeTypeEqual(javaRemoteObjectMimeType); 1296 } 1297 1298 1299 /** 1300 * Returns true if the <code>DataFlavor</code> specified represents 1301 * a list of file objects. 1302 * @return true if the <code>DataFlavor</code> specified represents 1303 * a List of File objects 1304 */ 1305 1306 public boolean isFlavorJavaFileListType() { 1307 if (mimeType == null || representationClass == null) 1308 return false; 1309 return java.util.List.class.isAssignableFrom(representationClass) && 1310 mimeType.match(javaFileListFlavor.mimeType); 1311 1312 } 1313 1314 /** 1315 * Returns whether this <code>DataFlavor</code> is a valid text flavor for 1316 * this implementation of the Java platform. Only flavors equivalent to 1317 * <code>DataFlavor.stringFlavor</code> and <code>DataFlavor</code>s with 1318 * a primary MIME type of "text" can be valid text flavors. 1319 * <p> 1320 * If this flavor supports the charset parameter, it must be equivalent to 1321 * <code>DataFlavor.stringFlavor</code>, or its representation must be 1322 * <code>java.io.Reader</code>, <code>java.lang.String</code>, 1323 * <code>java.nio.CharBuffer</code>, <code>[C</code>, 1324 * <code>java.io.InputStream</code>, <code>java.nio.ByteBuffer</code>, or 1325 * <code>[B</code>. If the representation is 1326 * <code>java.io.InputStream</code>, <code>java.nio.ByteBuffer</code>, or 1327 * <code>[B</code>, then this flavor's <code>charset</code> parameter must 1328 * be supported by this implementation of the Java platform. If a charset 1329 * is not specified, then the platform default charset, which is always 1330 * supported, is assumed. 1331 * <p> 1332 * If this flavor does not support the charset parameter, its 1333 * representation must be <code>java.io.InputStream</code>, 1334 * <code>java.nio.ByteBuffer</code>, or <code>[B</code>. 1335 * <p> 1336 * See <code>selectBestTextFlavor</code> for a list of text flavors which 1337 * support the charset parameter. 1338 * 1339 * @return <code>true</code> if this <code>DataFlavor</code> is a valid 1340 * text flavor as described above; <code>false</code> otherwise 1341 * @see #selectBestTextFlavor 1342 * @since 1.4 1343 */ 1344 public boolean isFlavorTextType() { 1345 return (DataTransferer.isFlavorCharsetTextType(this) || 1346 DataTransferer.isFlavorNoncharsetTextType(this)); 1347 } 1348 1349 /** 1350 * Serializes this <code>DataFlavor</code>. 1351 */ 1352 1353 public synchronized void writeExternal(ObjectOutput os) throws IOException { 1354 if (mimeType != null) { 1355 mimeType.setParameter("humanPresentableName", humanPresentableName); 1356 os.writeObject(mimeType); 1357 mimeType.removeParameter("humanPresentableName"); 1358 } else { 1359 os.writeObject(null); 1360 } 1361 1362 os.writeObject(representationClass); 1363 } 1364 1365 /** 1366 * Restores this <code>DataFlavor</code> from a Serialized state. 1367 */ 1368 1369 public synchronized void readExternal(ObjectInput is) throws IOException , ClassNotFoundException { 1370 String rcn = null; 1371 mimeType = (MimeType)is.readObject(); 1372 1373 if (mimeType != null) { 1374 humanPresentableName = 1375 mimeType.getParameter("humanPresentableName"); 1376 mimeType.removeParameter("humanPresentableName"); 1377 rcn = mimeType.getParameter("class"); 1378 if (rcn == null) { 1379 throw new IOException("no class parameter specified in: " + 1380 mimeType); 1381 } 1382 } 1383 1384 try { 1385 representationClass = (Class)is.readObject(); 1386 } catch (OptionalDataException ode) { 1387 if (!ode.eof || ode.length != 0) { 1388 throw ode; 1389 } 1390 // Ensure backward compatibility. 1391 // Old versions didn't write the representation class to the stream. 1392 if (rcn != null) { 1393 representationClass = 1394 DataFlavor.tryToLoadClass(rcn, getClass().getClassLoader()); 1395 } 1396 } 1397 } 1398 1399 /** 1400 * Returns a clone of this <code>DataFlavor</code>. 1401 * @return a clone of this <code>DataFlavor</code> 1402 */ 1403 1404 public Object clone() throws CloneNotSupportedException { 1405 Object newObj = super.clone(); 1406 if (mimeType != null) { 1407 ((DataFlavor)newObj).mimeType = (MimeType)mimeType.clone(); 1408 } 1409 return newObj; 1410 } // clone() 1411 1412 /** 1413 * Called on <code>DataFlavor</code> for every MIME Type parameter 1414 * to allow <code>DataFlavor</code> subclasses to handle special 1415 * parameters like the text/plain <code>charset</code> 1416 * parameters, whose values are case insensitive. (MIME type parameter 1417 * values are supposed to be case sensitive. 1418 * <p> 1419 * This method is called for each parameter name/value pair and should 1420 * return the normalized representation of the <code>parameterValue</code>. 1421 * 1422 * This method is never invoked by this implementation from 1.1 onwards. 1423 * 1424 * @deprecated 1425 */ 1426 @Deprecated 1427 protected String normalizeMimeTypeParameter(String parameterName, String parameterValue) { 1428 return parameterValue; 1429 } 1430 1431 /** 1432 * Called for each MIME type string to give <code>DataFlavor</code> subtypes 1433 * the opportunity to change how the normalization of MIME types is 1434 * accomplished. One possible use would be to add default 1435 * parameter/value pairs in cases where none are present in the MIME 1436 * type string passed in. 1437 * 1438 * This method is never invoked by this implementation from 1.1 onwards. 1439 * 1440 * @deprecated 1441 */ 1442 @Deprecated 1443 protected String normalizeMimeType(String mimeType) { 1444 return mimeType; 1445 } 1446 1447 /* 1448 * fields 1449 */ 1450 1451 /* placeholder for caching any platform-specific data for flavor */ 1452 1453 transient int atom; 1454 1455 /* Mime Type of DataFlavor */ 1456 1457 MimeType mimeType; 1458 1459 private String humanPresentableName; 1460 1461 /** Java class of objects this DataFlavor represents **/ 1462 1463 private Class<?> representationClass; 1464 1465 } // class DataFlavor