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