1 /* 2 * Copyright (c) 1996, 2017, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package java.awt.datatransfer; 27 28 import java.io.ByteArrayInputStream; 29 import java.io.CharArrayReader; 30 import java.io.Externalizable; 31 import java.io.IOException; 32 import java.io.InputStream; 33 import java.io.InputStreamReader; 34 import java.io.ObjectInput; 35 import java.io.ObjectOutput; 36 import java.io.OptionalDataException; 37 import java.io.Reader; 38 import java.io.StringReader; 39 import java.io.UnsupportedEncodingException; 40 import java.nio.ByteBuffer; 41 import java.nio.CharBuffer; 42 import java.util.Arrays; 43 import java.util.Collections; 44 import java.util.Objects; 45 46 import sun.datatransfer.DataFlavorUtil; 47 import sun.reflect.misc.ReflectUtil; 48 49 /** 50 * A {@code DataFlavor} provides meta information about data. {@code DataFlavor} 51 * is typically used to access data on the clipboard, or during a drag and drop 52 * operation. 53 * <p> 54 * An instance of {@code DataFlavor} encapsulates a content type as defined in 55 * <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045</a> and 56 * <a href="http://www.ietf.org/rfc/rfc2046.txt">RFC 2046</a>. A content type is 57 * typically referred to as a MIME type. 58 * <p> 59 * A content type consists of a media type (referred to as the primary type), a 60 * subtype, and optional parameters. See 61 * <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045</a> for details on the 62 * syntax of a MIME type. 63 * <p> 64 * The JRE data transfer implementation interprets the parameter 65 * "class" of a MIME type as <B>a representation class</b>. The 66 * representation class reflects the class of the object being transferred. In 67 * other words, the representation class is the type of object returned by 68 * {@link Transferable#getTransferData}. For example, the MIME type of 69 * {@link #imageFlavor} is {@code "image/x-java-image;class=java.awt.Image"}, 70 * the primary type is {@code image}, the subtype is {@code x-java-image}, and 71 * the representation class is {@code java.awt.Image}. When 72 * {@code getTransferData} is invoked with a {@code DataFlavor} of 73 * {@code imageFlavor}, an instance of {@code java.awt.Image} is returned. It's 74 * important to note that {@code DataFlavor} does no error checking against the 75 * representation class. It is up to consumers of {@code DataFlavor}, such as 76 * {@code Transferable}, to honor the representation class. 77 * <br> 78 * Note, if you do not specify a representation class when creating a 79 * {@code DataFlavor}, the default representation class is used. See appropriate 80 * documentation for {@code DataFlavor}'s constructors. 81 * <p> 82 * Also, {@code DataFlavor} instances with the "text" primary MIME 83 * type may have a "charset" parameter. Refer to 84 * <a href="http://www.ietf.org/rfc/rfc2046.txt">RFC 2046</a> and 85 * {@link #selectBestTextFlavor} for details on "text" MIME types and 86 * the "charset" parameter. 87 * <p> 88 * Equality of {@code DataFlavors} is determined by the primary type, subtype, 89 * and representation class. Refer to {@link #equals(DataFlavor)} for details. 90 * When determining equality, any optional parameters are ignored. For example, 91 * the following produces two {@code DataFlavors} that are considered identical: 92 * <pre> 93 * DataFlavor flavor1 = new DataFlavor(Object.class, "X-test/test; class=<java.lang.Object>; foo=bar"); 94 * DataFlavor flavor2 = new DataFlavor(Object.class, "X-test/test; class=<java.lang.Object>; x=y"); 95 * // The following returns true. 96 * flavor1.equals(flavor2); 97 * </pre> 98 * As mentioned, {@code flavor1} and {@code flavor2} are considered identical. 99 * As such, asking a {@code Transferable} for either {@code DataFlavor} returns 100 * the same results. 101 * <p> 102 * For more information on using data transfer with Swing see the 103 * <a href="http://docs.oracle.com/javase/tutorial/uiswing/dnd/index.html">How 104 * to Use Drag and Drop and Data Transfer</a>, section in 105 * <em>Java Tutorial</em>. 106 * 107 * @author Blake Sullivan 108 * @author Laurence P. G. Cable 109 * @author Jeff Dunn 110 */ 111 public class DataFlavor implements Externalizable, Cloneable { 112 113 private static final long serialVersionUID = 8367026044764648243L; 114 private static final Class<InputStream> ioInputStreamClass = InputStream.class; 115 116 /** 117 * Tries to load a class from: the bootstrap loader, the system loader, the 118 * context loader (if one is present) and finally the loader specified. 119 * 120 * @param className the name of the class to be loaded 121 * @param fallback the fallback loader 122 * @return the class loaded 123 * @throws ClassNotFoundException if class is not found 124 */ 125 protected static final Class<?> tryToLoadClass(String className, 126 ClassLoader fallback) 127 throws ClassNotFoundException 128 { 129 ReflectUtil.checkPackageAccess(className); 130 try { 131 SecurityManager sm = System.getSecurityManager(); 132 if (sm != null) { 133 sm.checkPermission(new RuntimePermission("getClassLoader")); 134 } 135 ClassLoader loader = ClassLoader.getSystemClassLoader(); 136 try { 137 // bootstrap class loader and system class loader if present 138 return Class.forName(className, true, loader); 139 } 140 catch (ClassNotFoundException exception) { 141 // thread context class loader if and only if present 142 loader = Thread.currentThread().getContextClassLoader(); 143 if (loader != null) { 144 try { 145 return Class.forName(className, true, loader); 146 } 147 catch (ClassNotFoundException e) { 148 // fallback to user's class loader 149 } 150 } 151 } 152 } catch (SecurityException exception) { 153 // ignore secured class loaders 154 } 155 return Class.forName(className, true, fallback); 156 } 157 158 /* 159 * private initializer 160 */ 161 private static DataFlavor createConstant(Class<?> rc, String prn) { 162 try { 163 return new DataFlavor(rc, prn); 164 } catch (Exception e) { 165 return null; 166 } 167 } 168 169 /* 170 * private initializer 171 */ 172 private static DataFlavor createConstant(String mt, String prn) { 173 try { 174 return new DataFlavor(mt, prn); 175 } catch (Exception e) { 176 return null; 177 } 178 } 179 180 /* 181 * private initializer 182 */ 183 private static DataFlavor initHtmlDataFlavor(String htmlFlavorType) { 184 try { 185 return new DataFlavor ("text/html; class=java.lang.String;document=" + 186 htmlFlavorType + ";charset=Unicode"); 187 } catch (Exception e) { 188 return null; 189 } 190 } 191 192 /** 193 * The {@code DataFlavor} representing a Java Unicode String class, where: 194 * <pre> 195 * representationClass = java.lang.String 196 * mimeType = "application/x-java-serialized-object" 197 * </pre> 198 */ 199 public static final DataFlavor stringFlavor = createConstant(java.lang.String.class, "Unicode String"); 200 201 /** 202 * The {@code DataFlavor} representing a Java Image class, where: 203 * <pre> 204 * representationClass = java.awt.Image 205 * mimeType = "image/x-java-image" 206 * </pre> 207 * Will be {@code null} if {@code java.awt.Image} is not visible, the 208 * {@code java.desktop} module is not loaded, or the {@code java.desktop} 209 * module is not in the run-time image. 210 */ 211 public static final DataFlavor imageFlavor = createConstant("image/x-java-image; class=java.awt.Image", "Image"); 212 213 /** 214 * The {@code DataFlavor} representing plain text with Unicode encoding, 215 * where: 216 * <pre> 217 * representationClass = InputStream 218 * mimeType = "text/plain; charset=unicode" 219 * </pre> 220 * This {@code DataFlavor} has been <b>deprecated</b> because: 221 * <ul> 222 * <li>Its representation is an InputStream, an 8-bit based representation, 223 * while Unicode is a 16-bit character set</li> 224 * <li>The charset "unicode" is not well-defined. "unicode" implies a 225 * particular platform's implementation of Unicode, not a cross-platform 226 * implementation</li> 227 * </ul> 228 * 229 * @deprecated as of 1.3. Use {@link #getReaderForText} instead of 230 * {@code Transferable.getTransferData(DataFlavor.plainTextFlavor)}. 231 */ 232 @Deprecated 233 public static final DataFlavor plainTextFlavor = createConstant("text/plain; charset=unicode; class=java.io.InputStream", "Plain Text"); 234 235 /** 236 * A MIME Content-Type of application/x-java-serialized-object represents a 237 * graph of Java object(s) that have been made persistent. 238 * <p> 239 * The representation class associated with this {@code DataFlavor} 240 * identifies the Java type of an object returned as a reference from an 241 * invocation {@code java.awt.datatransfer.getTransferData}. 242 */ 243 public static final String javaSerializedObjectMimeType = "application/x-java-serialized-object"; 244 245 /** 246 * To transfer a list of files to/from Java (and the underlying platform) a 247 * {@code DataFlavor} of this type/subtype and representation class of 248 * {@code java.util.List} is used. Each element of the list is 249 * required/guaranteed to be of type {@code java.io.File}. 250 */ 251 public static final DataFlavor javaFileListFlavor = createConstant("application/x-java-file-list;class=java.util.List", null); 252 253 /** 254 * To transfer a reference to an arbitrary Java object reference that has no 255 * associated MIME Content-type, across a {@code Transferable} interface 256 * WITHIN THE SAME JVM, a {@code DataFlavor} with this type/subtype is used, 257 * with a {@code representationClass} equal to the type of the 258 * class/interface being passed across the {@code Transferable}. 259 * <p> 260 * The object reference returned from {@code Transferable.getTransferData} 261 * for a {@code DataFlavor} with this MIME Content-Type is required to be an 262 * instance of the representation Class of the {@code DataFlavor}. 263 */ 264 public static final String javaJVMLocalObjectMimeType = "application/x-java-jvm-local-objectref"; 265 266 /** 267 * In order to pass a live link to a Remote object via a Drag and Drop 268 * {@code ACTION_LINK} operation a Mime Content Type of 269 * application/x-java-remote-object should be used, where the representation 270 * class of the {@code DataFlavor} represents the type of the {@code Remote} 271 * interface to be transferred. 272 */ 273 public static final String javaRemoteObjectMimeType = "application/x-java-remote-object"; 274 275 /** 276 * Represents a piece of an HTML markup. The markup consists of the part 277 * selected on the source side. Therefore some tags in the markup may be 278 * unpaired. If the flavor is used to represent the data in a 279 * {@link Transferable} instance, no additional changes will be made. This 280 * DataFlavor instance represents the same HTML markup as DataFlavor 281 * instances which content MIME type does not contain document parameter 282 * and representation class is the String class. 283 * <pre> 284 * representationClass = String 285 * mimeType = "text/html" 286 * </pre> 287 * 288 * @since 1.8 289 */ 290 public static DataFlavor selectionHtmlFlavor = initHtmlDataFlavor("selection"); 291 292 /** 293 * Represents a piece of an HTML markup. If possible, the markup received 294 * from a native system is supplemented with pair tags to be a well-formed 295 * HTML markup. If the flavor is used to represent the data in a 296 * {@link Transferable} instance, no additional changes will be made. 297 * <pre> 298 * representationClass = String 299 * mimeType = "text/html" 300 * </pre> 301 * 302 * @since 1.8 303 */ 304 public static DataFlavor fragmentHtmlFlavor = initHtmlDataFlavor("fragment"); 305 306 /** 307 * Represents a piece of an HTML markup. If possible, the markup received 308 * from a native system is supplemented with additional tags to make up a 309 * well-formed HTML document. If the flavor is used to represent the data in 310 * a {@link Transferable} instance, no additional changes will be made. 311 * <pre> 312 * representationClass = String 313 * mimeType = "text/html" 314 * </pre> 315 * 316 * @since 1.8 317 */ 318 public static DataFlavor allHtmlFlavor = initHtmlDataFlavor("all"); 319 320 /** 321 * Constructs a new {@code DataFlavor}. This constructor is provided only 322 * for the purpose of supporting the {@code Externalizable} interface. It is 323 * not intended for public (client) use. 324 * 325 * @since 1.2 326 */ 327 public DataFlavor() { 328 super(); 329 } 330 331 /** 332 * Constructs a fully specified {@code DataFlavor}. 333 * 334 * @throws NullPointerException if either {@code primaryType}, 335 * {@code subType} or {@code representationClass} is {@code null} 336 */ 337 private DataFlavor(String primaryType, String subType, MimeTypeParameterList params, Class<?> representationClass, String humanPresentableName) { 338 super(); 339 if (primaryType == null) { 340 throw new NullPointerException("primaryType"); 341 } 342 if (subType == null) { 343 throw new NullPointerException("subType"); 344 } 345 if (representationClass == null) { 346 throw new NullPointerException("representationClass"); 347 } 348 349 if (params == null) params = new MimeTypeParameterList(); 350 351 params.set("class", representationClass.getName()); 352 353 if (humanPresentableName == null) { 354 humanPresentableName = params.get("humanPresentableName"); 355 356 if (humanPresentableName == null) 357 humanPresentableName = primaryType + "/" + subType; 358 } 359 360 try { 361 mimeType = new MimeType(primaryType, subType, params); 362 } catch (MimeTypeParseException mtpe) { 363 throw new IllegalArgumentException("MimeType Parse Exception: " + mtpe.getMessage()); 364 } 365 366 this.representationClass = representationClass; 367 this.humanPresentableName = humanPresentableName; 368 369 mimeType.removeParameter("humanPresentableName"); 370 } 371 372 /** 373 * Constructs a {@code DataFlavor} that represents a Java class. 374 * <p> 375 * The returned {@code DataFlavor} will have the following characteristics: 376 * <pre> 377 * representationClass = representationClass 378 * mimeType = application/x-java-serialized-object 379 * </pre> 380 * 381 * @param representationClass the class used to transfer data in this 382 * flavor 383 * @param humanPresentableName the human-readable string used to identify 384 * this flavor; if this parameter is {@code null} then the value of 385 * the MIME Content Type is used 386 * @throws NullPointerException if {@code representationClass} is 387 * {@code null} 388 */ 389 public DataFlavor(Class<?> representationClass, String humanPresentableName) { 390 this("application", "x-java-serialized-object", null, representationClass, humanPresentableName); 391 if (representationClass == null) { 392 throw new NullPointerException("representationClass"); 393 } 394 } 395 396 /** 397 * Constructs a {@code DataFlavor} that represents a {@code MimeType}. 398 * <p> 399 * The returned {@code DataFlavor} will have the following characteristics: 400 * <p> 401 * If the {@code mimeType} is 402 * "application/x-java-serialized-object; class=<representation class>", 403 * the result is the same as calling 404 * {@code new DataFlavor(Class.forName(<representation class>)}. 405 * <p> 406 * Otherwise: 407 * <pre> 408 * representationClass = InputStream 409 * mimeType = mimeType 410 * </pre> 411 * 412 * @param mimeType the string used to identify the MIME type for this 413 * flavor; if the {@code mimeType} does not specify a "class=" 414 * parameter, or if the class is not successfully loaded, then an 415 * {@code IllegalArgumentException} is thrown 416 * @param humanPresentableName the human-readable string used to identify 417 * this flavor; if this parameter is {@code null} then the value of 418 * the MIME Content Type is used 419 * @throws IllegalArgumentException if {@code mimeType} is invalid or if the 420 * class is not successfully loaded 421 * @throws NullPointerException if {@code mimeType} is {@code null} 422 */ 423 public DataFlavor(String mimeType, String humanPresentableName) { 424 super(); 425 if (mimeType == null) { 426 throw new NullPointerException("mimeType"); 427 } 428 try { 429 initialize(mimeType, humanPresentableName, this.getClass().getClassLoader()); 430 } catch (MimeTypeParseException mtpe) { 431 throw new IllegalArgumentException("failed to parse:" + mimeType); 432 } catch (ClassNotFoundException cnfe) { 433 throw new IllegalArgumentException("can't find specified class: " + cnfe.getMessage()); 434 } 435 } 436 437 /** 438 * Constructs a {@code DataFlavor} that represents a {@code MimeType}. 439 * <p> 440 * The returned {@code DataFlavor} will have the following characteristics: 441 * <p> 442 * If the mimeType is 443 * "application/x-java-serialized-object; class=<representation class>", 444 * the result is the same as calling 445 * {@code new DataFlavor(Class.forName(<representation class>)}. 446 * <p> 447 * Otherwise: 448 * <pre> 449 * representationClass = InputStream 450 * mimeType = mimeType 451 * </pre> 452 * 453 * @param mimeType the string used to identify the MIME type for this 454 * flavor 455 * @param humanPresentableName the human-readable string used to identify 456 * this flavor 457 * @param classLoader the class loader to use 458 * @throws ClassNotFoundException if the class is not loaded 459 * @throws IllegalArgumentException if {@code mimeType} is invalid 460 * @throws NullPointerException if {@code mimeType} is {@code null} 461 */ 462 public DataFlavor(String mimeType, String humanPresentableName, ClassLoader classLoader) throws ClassNotFoundException { 463 super(); 464 if (mimeType == null) { 465 throw new NullPointerException("mimeType"); 466 } 467 try { 468 initialize(mimeType, humanPresentableName, classLoader); 469 } catch (MimeTypeParseException mtpe) { 470 throw new IllegalArgumentException("failed to parse:" + mimeType); 471 } 472 } 473 474 /** 475 * Constructs a {@code DataFlavor} from a {@code mimeType} string. The 476 * string can specify a "class=<fully specified Java class name>" 477 * parameter to create a {@code DataFlavor} with the desired representation 478 * class. If the string does not contain "class=" parameter, 479 * {@code java.io.InputStream} is used as default. 480 * 481 * @param mimeType the string used to identify the MIME type for this 482 * flavor; if the class specified by "class=" parameter is not 483 * successfully loaded, then an {@code ClassNotFoundException} is 484 * thrown 485 * @throws ClassNotFoundException if the class is not loaded 486 * @throws IllegalArgumentException if {@code mimeType} is invalid 487 * @throws NullPointerException if {@code mimeType} is {@code null} 488 */ 489 public DataFlavor(String mimeType) throws ClassNotFoundException { 490 super(); 491 if (mimeType == null) { 492 throw new NullPointerException("mimeType"); 493 } 494 try { 495 initialize(mimeType, null, this.getClass().getClassLoader()); 496 } catch (MimeTypeParseException mtpe) { 497 throw new IllegalArgumentException("failed to parse:" + mimeType); 498 } 499 } 500 501 /** 502 * Common initialization code called from various constructors. 503 * 504 * @param mimeType the MIME Content Type (must have a class= param) 505 * @param humanPresentableName the human Presentable Name or {@code null} 506 * @param classLoader the fallback class loader to resolve against 507 * @throws MimeTypeParseException 508 * @throws ClassNotFoundException 509 * @throws NullPointerException if {@code mimeType} is {@code null} 510 * @see #tryToLoadClass 511 */ 512 private void initialize(String mimeType, String humanPresentableName, ClassLoader classLoader) throws MimeTypeParseException, ClassNotFoundException { 513 if (mimeType == null) { 514 throw new NullPointerException("mimeType"); 515 } 516 517 this.mimeType = new MimeType(mimeType); // throws 518 519 String rcn = getParameter("class"); 520 521 if (rcn == null) { 522 if ("application/x-java-serialized-object".equals(this.mimeType.getBaseType())) 523 524 throw new IllegalArgumentException("no representation class specified for:" + mimeType); 525 else 526 representationClass = java.io.InputStream.class; // default 527 } else { // got a class name 528 representationClass = DataFlavor.tryToLoadClass(rcn, classLoader); 529 } 530 531 this.mimeType.setParameter("class", representationClass.getName()); 532 533 if (humanPresentableName == null) { 534 humanPresentableName = this.mimeType.getParameter("humanPresentableName"); 535 if (humanPresentableName == null) 536 humanPresentableName = this.mimeType.getPrimaryType() + "/" + this.mimeType.getSubType(); 537 } 538 539 this.humanPresentableName = humanPresentableName; // set it. 540 541 this.mimeType.removeParameter("humanPresentableName"); // just in case 542 } 543 544 /** 545 * String representation of this {@code DataFlavor} and its parameters. The 546 * resulting {@code String} contains the name of the {@code DataFlavor} 547 * class, this flavor's MIME type, and its representation class. If this 548 * flavor has a primary MIME type of "text", supports the charset parameter, 549 * and has an encoded representation, the flavor's charset is also included. 550 * See {@code selectBestTextFlavor} for a list of text flavors which support 551 * the charset parameter. 552 * 553 * @return string representation of this {@code DataFlavor} 554 * @see #selectBestTextFlavor 555 */ 556 public String toString() { 557 String string = getClass().getName(); 558 string += "["+paramString()+"]"; 559 return string; 560 } 561 562 private String paramString() { 563 String params = ""; 564 params += "mimetype="; 565 if (mimeType == null) { 566 params += "null"; 567 } else { 568 params += mimeType.getBaseType(); 569 } 570 params += ";representationclass="; 571 if (representationClass == null) { 572 params += "null"; 573 } else { 574 params += representationClass.getName(); 575 } 576 if (DataFlavorUtil.isFlavorCharsetTextType(this) && 577 (isRepresentationClassInputStream() || 578 isRepresentationClassByteBuffer() || 579 byte[].class.equals(representationClass))) 580 { 581 params += ";charset=" + DataFlavorUtil.getTextCharset(this); 582 } 583 return params; 584 } 585 586 /** 587 * Returns a {@code DataFlavor} representing plain text with Unicode 588 * encoding, where: 589 * <pre> 590 * representationClass = java.io.InputStream 591 * mimeType = "text/plain; 592 * charset=<platform default Unicode encoding>" 593 * </pre> 594 * Sun's implementation for Microsoft Windows uses the encoding 595 * {@code utf-16le}. 596 * Sun's implementation for Solaris and Linux uses the encoding 597 * {@code iso-10646-ucs-2}. 598 * 599 * @return a {@code DataFlavor} representing plain text with Unicode 600 * encoding 601 * @since 1.3 602 */ 603 public static final DataFlavor getTextPlainUnicodeFlavor() { 604 return new DataFlavor( 605 "text/plain;charset=" + DataFlavorUtil.getDesktopService().getDefaultUnicodeEncoding() 606 +";class=java.io.InputStream", "Plain Text"); 607 } 608 609 /** 610 * Selects the best text {@code DataFlavor} from an array of 611 * {@code DataFlavor}s. Only {@code DataFlavor.stringFlavor}, and equivalent 612 * flavors, and flavors that have a primary MIME type of "text", are 613 * considered for selection. 614 * <p> 615 * Flavors are first sorted by their MIME types in the following order: 616 * <ul> 617 * <li>"text/sgml" 618 * <li>"text/xml" 619 * <li>"text/html" 620 * <li>"text/rtf" 621 * <li>"text/enriched" 622 * <li>"text/richtext" 623 * <li>"text/uri-list" 624 * <li>"text/tab-separated-values" 625 * <li>"text/t140" 626 * <li>"text/rfc822-headers" 627 * <li>"text/parityfec" 628 * <li>"text/directory" 629 * <li>"text/css" 630 * <li>"text/calendar" 631 * <li>"application/x-java-serialized-object" 632 * <li>"text/plain" 633 * <li>"text/<other>" 634 * </ul> 635 * <p> 636 * For example, "text/sgml" will be selected over "text/html", and 637 * {@code DataFlavor.stringFlavor} will be chosen over 638 * {@code DataFlavor.plainTextFlavor}. 639 * <p> 640 * If two or more flavors share the best MIME type in the array, then that 641 * MIME type will be checked to see if it supports the charset parameter. 642 * <p> 643 * The following MIME types support, or are treated as though they support, 644 * the charset parameter: 645 * <ul> 646 * <li>"text/sgml" 647 * <li>"text/xml" 648 * <li>"text/html" 649 * <li>"text/enriched" 650 * <li>"text/richtext" 651 * <li>"text/uri-list" 652 * <li>"text/directory" 653 * <li>"text/css" 654 * <li>"text/calendar" 655 * <li>"application/x-java-serialized-object" 656 * <li>"text/plain" 657 * </ul> 658 * The following MIME types do not support, or are treated as though they do 659 * not support, the charset parameter: 660 * <ul> 661 * <li>"text/rtf" 662 * <li>"text/tab-separated-values" 663 * <li>"text/t140" 664 * <li>"text/rfc822-headers" 665 * <li>"text/parityfec" 666 * </ul> 667 * For "text/<other>" MIME types, the first time the JRE needs to 668 * determine whether the MIME type supports the charset parameter, it will 669 * check whether the parameter is explicitly listed in an arbitrarily chosen 670 * {@code DataFlavor} which uses that MIME type. If so, the JRE will assume 671 * from that point on that the MIME type supports the charset parameter and 672 * will not check again. If the parameter is not explicitly listed, the JRE 673 * will assume from that point on that the MIME type does not support the 674 * charset parameter and will not check again. Because this check is 675 * performed on an arbitrarily chosen {@code DataFlavor}, developers must 676 * ensure that all {@code DataFlavor}s with a "text/<other>" MIME type 677 * specify the charset parameter if it is supported by that MIME type. 678 * Developers should never rely on the JRE to substitute the platform's 679 * default charset for a "text/<other>" DataFlavor. Failure to adhere 680 * to this restriction will lead to undefined behavior. 681 * <p> 682 * If the best MIME type in the array does not support the charset 683 * parameter, the flavors which share that MIME type will then be sorted by 684 * their representation classes in the following order: 685 * {@code java.io.InputStream}, {@code java.nio.ByteBuffer}, {@code [B}, 686 * <all others>. 687 * <p> 688 * If two or more flavors share the best representation class, or if no 689 * flavor has one of the three specified representations, then one of those 690 * flavors will be chosen non-deterministically. 691 * <p> 692 * If the best MIME type in the array does support the charset parameter, 693 * the flavors which share that MIME type will then be sorted by their 694 * representation classes in the following order: {@code java.io.Reader}, 695 * {@code java.lang.String}, {@code java.nio.CharBuffer}, {@code [C}, 696 * <all others>. 697 * <p> 698 * If two or more flavors share the best representation class, and that 699 * representation is one of the four explicitly listed, then one of those 700 * flavors will be chosen non-deterministically. If, however, no flavor has 701 * one of the four specified representations, the flavors will then be 702 * sorted by their charsets. Unicode charsets, such as "UTF-16", "UTF-8", 703 * "UTF-16BE", "UTF-16LE", and their aliases, are considered best. After 704 * them, the platform default charset and its aliases are selected. 705 * "US-ASCII" and its aliases are worst. All other charsets are chosen in 706 * alphabetical order, but only charsets supported by this implementation of 707 * the Java platform will be considered. 708 * <p> 709 * If two or more flavors share the best charset, the flavors will then 710 * again be sorted by their representation classes in the following order: 711 * {@code java.io.InputStream}, {@code java.nio.ByteBuffer}, {@code [B}, 712 * <all others>. 713 * <p> 714 * If two or more flavors share the best representation class, or if no 715 * flavor has one of the three specified representations, then one of those 716 * flavors will be chosen non-deterministically. 717 * 718 * @param availableFlavors an array of available {@code DataFlavor}s 719 * @return the best (highest fidelity) flavor according to the rules 720 * specified above, or {@code null}, if {@code availableFlavors} is 721 * {@code null}, has zero length, or contains no text flavors 722 * @since 1.3 723 */ 724 public static final DataFlavor selectBestTextFlavor( 725 DataFlavor[] availableFlavors) { 726 if (availableFlavors == null || availableFlavors.length == 0) { 727 return null; 728 } 729 730 DataFlavor bestFlavor = Collections.max(Arrays.asList(availableFlavors), 731 DataFlavorUtil.getTextFlavorComparator()); 732 733 if (!bestFlavor.isFlavorTextType()) { 734 return null; 735 } 736 737 return bestFlavor; 738 } 739 740 /** 741 * Gets a Reader for a text flavor, decoded, if necessary, for the expected 742 * charset (encoding). The supported representation classes are 743 * {@code java.io.Reader}, {@code java.lang.String}, 744 * {@code java.nio.CharBuffer}, {@code [C}, {@code java.io.InputStream}, 745 * {@code java.nio.ByteBuffer}, and {@code [B}. 746 * <p> 747 * Because text flavors which do not support the charset parameter are 748 * encoded in a non-standard format, this method should not be called for 749 * such flavors. However, in order to maintain backward-compatibility, if 750 * this method is called for such a flavor, this method will treat the 751 * flavor as though it supports the charset parameter and attempt to decode 752 * it accordingly. See {@code selectBestTextFlavor} for a list of text 753 * flavors which do not support the charset parameter. 754 * 755 * @param transferable the {@code Transferable} whose data will be 756 * requested in this flavor 757 * @return a {@code Reader} to read the {@code Transferable}'s data 758 * @throws IllegalArgumentException if the representation class is not one 759 * of the seven listed above 760 * @throws IllegalArgumentException if the {@code Transferable} has 761 * {@code null} data 762 * @throws NullPointerException if the {@code Transferable} is {@code null} 763 * @throws UnsupportedEncodingException if this flavor's representation is 764 * {@code java.io.InputStream}, {@code java.nio.ByteBuffer}, or 765 * {@code [B} and this flavor's encoding is not supported by this 766 * implementation of the Java platform 767 * @throws UnsupportedFlavorException if the {@code Transferable} does not 768 * support this flavor 769 * @throws IOException if the data cannot be read because of an I/O error 770 * @see #selectBestTextFlavor 771 * @since 1.3 772 */ 773 public Reader getReaderForText(Transferable transferable) 774 throws UnsupportedFlavorException, IOException 775 { 776 Object transferObject = transferable.getTransferData(this); 777 if (transferObject == null) { 778 throw new IllegalArgumentException 779 ("getTransferData() returned null"); 780 } 781 782 if (transferObject instanceof Reader) { 783 return (Reader)transferObject; 784 } else if (transferObject instanceof String) { 785 return new StringReader((String)transferObject); 786 } else if (transferObject instanceof CharBuffer) { 787 CharBuffer buffer = (CharBuffer)transferObject; 788 int size = buffer.remaining(); 789 char[] chars = new char[size]; 790 buffer.get(chars, 0, size); 791 return new CharArrayReader(chars); 792 } else if (transferObject instanceof char[]) { 793 return new CharArrayReader((char[])transferObject); 794 } 795 796 InputStream stream = null; 797 798 if (transferObject instanceof InputStream) { 799 stream = (InputStream)transferObject; 800 } else if (transferObject instanceof ByteBuffer) { 801 ByteBuffer buffer = (ByteBuffer)transferObject; 802 int size = buffer.remaining(); 803 byte[] bytes = new byte[size]; 804 buffer.get(bytes, 0, size); 805 stream = new ByteArrayInputStream(bytes); 806 } else if (transferObject instanceof byte[]) { 807 stream = new ByteArrayInputStream((byte[])transferObject); 808 } 809 810 if (stream == null) { 811 throw new IllegalArgumentException("transfer data is not Reader, String, CharBuffer, char array, InputStream, ByteBuffer, or byte array"); 812 } 813 814 String encoding = getParameter("charset"); 815 return (encoding == null) 816 ? new InputStreamReader(stream) 817 : new InputStreamReader(stream, encoding); 818 } 819 820 /** 821 * Returns the MIME type string for this {@code DataFlavor}. 822 * 823 * @return the MIME type string for this flavor 824 */ 825 public String getMimeType() { 826 return (mimeType != null) ? mimeType.toString() : null; 827 } 828 829 /** 830 * Returns the {@code Class} which objects supporting this 831 * {@code DataFlavor} will return when this {@code DataFlavor} is requested. 832 * 833 * @return the {@code Class} which objects supporting this 834 * {@code DataFlavor} will return when this {@code DataFlavor} is 835 * requested 836 */ 837 public Class<?> getRepresentationClass() { 838 return representationClass; 839 } 840 841 /** 842 * Returns the human presentable name for the data format that this 843 * {@code DataFlavor} represents. This name would be localized for different 844 * countries. 845 * 846 * @return the human presentable name for the data format that this 847 * {@code DataFlavor} represents 848 */ 849 public String getHumanPresentableName() { 850 return humanPresentableName; 851 } 852 853 /** 854 * Returns the primary MIME type for this {@code DataFlavor}. 855 * 856 * @return the primary MIME type of this {@code DataFlavor} 857 */ 858 public String getPrimaryType() { 859 return (mimeType != null) ? mimeType.getPrimaryType() : null; 860 } 861 862 /** 863 * Returns the sub MIME type of this {@code DataFlavor}. 864 * 865 * @return the Sub MIME type of this {@code DataFlavor} 866 */ 867 public String getSubType() { 868 return (mimeType != null) ? mimeType.getSubType() : null; 869 } 870 871 /** 872 * Returns the human presentable name for this {@code DataFlavor} if 873 * {@code paramName} equals "humanPresentableName". Otherwise returns the 874 * MIME type value associated with {@code paramName}. 875 * 876 * @param paramName the parameter name requested 877 * @return the value of the name parameter, or {@code null} if there is no 878 * associated value 879 */ 880 public String getParameter(String paramName) { 881 if (paramName.equals("humanPresentableName")) { 882 return humanPresentableName; 883 } else { 884 return (mimeType != null) 885 ? mimeType.getParameter(paramName) : null; 886 } 887 } 888 889 /** 890 * Sets the human presentable name for the data format that this 891 * {@code DataFlavor} represents. This name would be localized for different 892 * countries. 893 * 894 * @param humanPresentableName the new human presentable name 895 */ 896 public void setHumanPresentableName(String humanPresentableName) { 897 this.humanPresentableName = humanPresentableName; 898 } 899 900 /** 901 * {@inheritDoc} 902 * <p> 903 * The equals comparison for the {@code DataFlavor} class is implemented as 904 * follows: Two {@code DataFlavor}s are considered equal if and only if 905 * their MIME primary type and subtype and representation class are equal. 906 * Additionally, if the primary type is "text", the subtype denotes a text 907 * flavor which supports the charset parameter, and the representation class 908 * is not {@code java.io.Reader}, {@code java.lang.String}, 909 * {@code java.nio.CharBuffer}, or {@code [C}, the {@code charset} parameter 910 * must also be equal. If a charset is not explicitly specified for one or 911 * both {@code DataFlavor}s, the platform default encoding is assumed. See 912 * {@code selectBestTextFlavor} for a list of text flavors which support the 913 * charset parameter. 914 * 915 * @param o the {@code Object} to compare with {@code this} 916 * @return {@code true} if {@code that} is equivalent to this 917 * {@code DataFlavor}; {@code false} otherwise 918 * @see #selectBestTextFlavor 919 */ 920 public boolean equals(Object o) { 921 return ((o instanceof DataFlavor) && equals((DataFlavor)o)); 922 } 923 924 /** 925 * This method has the same behavior as {@link #equals(Object)}. The only 926 * difference being that it takes a {@code DataFlavor} instance as a 927 * parameter. 928 * 929 * @param that the {@code DataFlavor} to compare with {@code this} 930 * @return {@code true} if {@code that} is equivalent to this 931 * {@code DataFlavor}; {@code false} otherwise 932 * @see #selectBestTextFlavor 933 */ 934 public boolean equals(DataFlavor that) { 935 if (that == null) { 936 return false; 937 } 938 if (this == that) { 939 return true; 940 } 941 942 if (!Objects.equals(this.getRepresentationClass(), that.getRepresentationClass())) { 943 return false; 944 } 945 946 if (mimeType == null) { 947 if (that.mimeType != null) { 948 return false; 949 } 950 } else { 951 if (!mimeType.match(that.mimeType)) { 952 return false; 953 } 954 955 if ("text".equals(getPrimaryType())) { 956 if (DataFlavorUtil.doesSubtypeSupportCharset(this) 957 && representationClass != null 958 && !isStandardTextRepresentationClass()) { 959 String thisCharset = 960 DataFlavorUtil.canonicalName(this.getParameter("charset")); 961 String thatCharset = 962 DataFlavorUtil.canonicalName(that.getParameter("charset")); 963 if (!Objects.equals(thisCharset, thatCharset)) { 964 return false; 965 } 966 } 967 968 if ("html".equals(getSubType())) { 969 String thisDocument = this.getParameter("document"); 970 String thatDocument = that.getParameter("document"); 971 if (!Objects.equals(thisDocument, thatDocument)) { 972 return false; 973 } 974 } 975 } 976 } 977 978 return true; 979 } 980 981 /** 982 * Compares only the {@code mimeType} against the passed in {@code String} 983 * and {@code representationClass} is not considered in the comparison. If 984 * {@code representationClass} needs to be compared, then 985 * {@code equals(new DataFlavor(s))} may be used. 986 * 987 * @param s the {@code mimeType} to compare 988 * @return {@code true} if the String (MimeType) is equal; {@code false} 989 * otherwise or if {@code s} is {@code null} 990 * @deprecated As inconsistent with {@code hashCode()} contract, use 991 * {@link #isMimeTypeEqual(String)} instead. 992 */ 993 @Deprecated 994 public boolean equals(String s) { 995 if (s == null || mimeType == null) 996 return false; 997 return isMimeTypeEqual(s); 998 } 999 1000 /** 1001 * Returns hash code for this {@code DataFlavor}. For two equal 1002 * {@code DataFlavor}s, hash codes are equal. For the {@code String} that 1003 * matches {@code DataFlavor.equals(String)}, it is not guaranteed that 1004 * {@code DataFlavor}'s hash code is equal to the hash code of the 1005 * {@code String}. 1006 * 1007 * @return a hash code for this {@code DataFlavor} 1008 */ 1009 public int hashCode() { 1010 int total = 0; 1011 1012 if (representationClass != null) { 1013 total += representationClass.hashCode(); 1014 } 1015 1016 if (mimeType != null) { 1017 String primaryType = mimeType.getPrimaryType(); 1018 if (primaryType != null) { 1019 total += primaryType.hashCode(); 1020 } 1021 1022 // Do not add subType.hashCode() to the total. equals uses 1023 // MimeType.match which reports a match if one or both of the 1024 // subTypes is '*', regardless of the other subType. 1025 1026 if ("text".equals(primaryType)) { 1027 if (DataFlavorUtil.doesSubtypeSupportCharset(this) 1028 && representationClass != null 1029 && !isStandardTextRepresentationClass()) { 1030 String charset = DataFlavorUtil.canonicalName(getParameter("charset")); 1031 if (charset != null) { 1032 total += charset.hashCode(); 1033 } 1034 } 1035 1036 if ("html".equals(getSubType())) { 1037 String document = this.getParameter("document"); 1038 if (document != null) { 1039 total += document.hashCode(); 1040 } 1041 } 1042 } 1043 } 1044 1045 return total; 1046 } 1047 1048 /** 1049 * Identical to {@link #equals(DataFlavor)}. 1050 * 1051 * @param that the {@code DataFlavor} to compare with {@code this} 1052 * @return {@code true} if {@code that} is equivalent to this 1053 * {@code DataFlavor}; {@code false} otherwise 1054 * @see #selectBestTextFlavor 1055 * @since 1.3 1056 */ 1057 public boolean match(DataFlavor that) { 1058 return equals(that); 1059 } 1060 1061 /** 1062 * Returns whether the string representation of the MIME type passed in is 1063 * equivalent to the MIME type of this {@code DataFlavor}. Parameters are 1064 * not included in the comparison. 1065 * 1066 * @param mimeType the string representation of the MIME type 1067 * @return {@code true} if the string representation of the MIME type passed 1068 * in is equivalent to the MIME type of this {@code DataFlavor}; 1069 * {@code false} otherwise 1070 * @throws NullPointerException if mimeType is {@code null} 1071 */ 1072 public boolean isMimeTypeEqual(String mimeType) { 1073 // JCK Test DataFlavor0117: if 'mimeType' is null, throw NPE 1074 if (mimeType == null) { 1075 throw new NullPointerException("mimeType"); 1076 } 1077 if (this.mimeType == null) { 1078 return false; 1079 } 1080 try { 1081 return this.mimeType.match(new MimeType(mimeType)); 1082 } catch (MimeTypeParseException mtpe) { 1083 return false; 1084 } 1085 } 1086 1087 /** 1088 * Compares the {@code mimeType} of two {@code DataFlavor} objects. No 1089 * parameters are considered. 1090 * 1091 * @param dataFlavor the {@code DataFlavor} to be compared 1092 * @return {@code true} if the {@code MimeType}s are equal, otherwise 1093 * {@code false} 1094 */ 1095 public final boolean isMimeTypeEqual(DataFlavor dataFlavor) { 1096 return isMimeTypeEqual(dataFlavor.mimeType); 1097 } 1098 1099 /** 1100 * Compares the {@code mimeType} of two {@code DataFlavor} objects. No 1101 * parameters are considered. 1102 * 1103 * @return {@code true} if the {@code MimeType}s are equal, otherwise 1104 * {@code false} 1105 */ 1106 private boolean isMimeTypeEqual(MimeType mtype) { 1107 if (this.mimeType == null) { 1108 return (mtype == null); 1109 } 1110 return mimeType.match(mtype); 1111 } 1112 1113 /** 1114 * Checks if the representation class is one of the standard text 1115 * representation classes. 1116 * 1117 * @return {@code true} if the representation class is one of the standard 1118 * text representation classes, otherwise {@code false} 1119 */ 1120 private boolean isStandardTextRepresentationClass() { 1121 return isRepresentationClassReader() 1122 || String.class.equals(representationClass) 1123 || isRepresentationClassCharBuffer() 1124 || char[].class.equals(representationClass); 1125 } 1126 1127 /** 1128 * Does the {@code DataFlavor} represent a serialized object? 1129 * 1130 * @return whether or not a serialized object is represented 1131 */ 1132 public boolean isMimeTypeSerializedObject() { 1133 return isMimeTypeEqual(javaSerializedObjectMimeType); 1134 } 1135 1136 /** 1137 * Returns the default representation class. 1138 * 1139 * @return the default representation class 1140 */ 1141 public final Class<?> getDefaultRepresentationClass() { 1142 return ioInputStreamClass; 1143 } 1144 1145 /** 1146 * Returns the name of the default representation class. 1147 * 1148 * @return the name of the default representation class 1149 */ 1150 public final String getDefaultRepresentationClassAsString() { 1151 return getDefaultRepresentationClass().getName(); 1152 } 1153 1154 /** 1155 * Does the {@code DataFlavor} represent a {@code java.io.InputStream}? 1156 * 1157 * @return whether or not this {@code DataFlavor} represent a 1158 * {@code java.io.InputStream} 1159 */ 1160 public boolean isRepresentationClassInputStream() { 1161 return ioInputStreamClass.isAssignableFrom(representationClass); 1162 } 1163 1164 /** 1165 * Returns whether the representation class for this {@code DataFlavor} is 1166 * {@code java.io.Reader} or a subclass thereof. 1167 * 1168 * @return whether or not the representation class for this 1169 * {@code DataFlavor} is {@code java.io.Reader} or a subclass 1170 * thereof 1171 * @since 1.4 1172 */ 1173 public boolean isRepresentationClassReader() { 1174 return java.io.Reader.class.isAssignableFrom(representationClass); 1175 } 1176 1177 /** 1178 * Returns whether the representation class for this {@code DataFlavor} is 1179 * {@code java.nio.CharBuffer} or a subclass thereof. 1180 * 1181 * @return whether or not the representation class for this 1182 * {@code DataFlavor} is {@code java.nio.CharBuffer} or a subclass 1183 * thereof 1184 * @since 1.4 1185 */ 1186 public boolean isRepresentationClassCharBuffer() { 1187 return java.nio.CharBuffer.class.isAssignableFrom(representationClass); 1188 } 1189 1190 /** 1191 * Returns whether the representation class for this {@code DataFlavor} is 1192 * {@code java.nio.ByteBuffer} or a subclass thereof. 1193 * 1194 * @return whether or not the representation class for this 1195 * {@code DataFlavor} is {@code java.nio.ByteBuffer} or a subclass 1196 * thereof 1197 * @since 1.4 1198 */ 1199 public boolean isRepresentationClassByteBuffer() { 1200 return java.nio.ByteBuffer.class.isAssignableFrom(representationClass); 1201 } 1202 1203 /** 1204 * Returns {@code true} if the representation class can be serialized. 1205 * 1206 * @return {@code true} if the representation class can be serialized 1207 */ 1208 public boolean isRepresentationClassSerializable() { 1209 return java.io.Serializable.class.isAssignableFrom(representationClass); 1210 } 1211 1212 /** 1213 * Returns {@code true} if the representation class is {@code Remote}. 1214 * 1215 * @return {@code true} if the representation class is {@code Remote} 1216 */ 1217 public boolean isRepresentationClassRemote() { 1218 return DataFlavorUtil.RMI.isRemote(representationClass); 1219 } 1220 1221 /** 1222 * Returns {@code true} if the {@code DataFlavor} specified represents a 1223 * serialized object. 1224 * 1225 * @return {@code true} if the {@code DataFlavor} specified represents a 1226 * Serialized Object 1227 */ 1228 public boolean isFlavorSerializedObjectType() { 1229 return isRepresentationClassSerializable() && isMimeTypeEqual(javaSerializedObjectMimeType); 1230 } 1231 1232 /** 1233 * Returns {@code true} if the {@code DataFlavor} specified represents a 1234 * remote object. 1235 * 1236 * @return {@code true} if the {@code DataFlavor} specified represents a 1237 * Remote Object 1238 */ 1239 public boolean isFlavorRemoteObjectType() { 1240 return isRepresentationClassRemote() 1241 && isRepresentationClassSerializable() 1242 && isMimeTypeEqual(javaRemoteObjectMimeType); 1243 } 1244 1245 /** 1246 * Returns {@code true} if the {@code DataFlavor} specified represents a 1247 * list of file objects. 1248 * 1249 * @return {@code true} if the {@code DataFlavor} specified represents a 1250 * List of File objects 1251 */ 1252 public boolean isFlavorJavaFileListType() { 1253 if (mimeType == null || representationClass == null) 1254 return false; 1255 return java.util.List.class.isAssignableFrom(representationClass) && 1256 mimeType.match(javaFileListFlavor.mimeType); 1257 1258 } 1259 1260 /** 1261 * Returns whether this {@code DataFlavor} is a valid text flavor for this 1262 * implementation of the Java platform. Only flavors equivalent to 1263 * {@code DataFlavor.stringFlavor} and {@code DataFlavor}s with a primary 1264 * MIME type of "text" can be valid text flavors. 1265 * <p> 1266 * If this flavor supports the charset parameter, it must be equivalent to 1267 * {@code DataFlavor.stringFlavor}, or its representation must be 1268 * {@code java.io.Reader}, {@code java.lang.String}, 1269 * {@code java.nio.CharBuffer}, {@code [C}, {@code java.io.InputStream}, 1270 * {@code java.nio.ByteBuffer}, or {@code [B}. If the representation is 1271 * {@code java.io.InputStream}, {@code java.nio.ByteBuffer}, or {@code [B}, 1272 * then this flavor's {@code charset} parameter must be supported by this 1273 * implementation of the Java platform. If a charset is not specified, then 1274 * the platform default charset, which is always supported, is assumed. 1275 * <p> 1276 * If this flavor does not support the charset parameter, its representation 1277 * must be {@code java.io.InputStream}, {@code java.nio.ByteBuffer}, or 1278 * {@code [B}. 1279 * <p> 1280 * See {@code selectBestTextFlavor} for a list of text flavors which support 1281 * the charset parameter. 1282 * 1283 * @return {@code true} if this {@code DataFlavor} is a valid text flavor as 1284 * described above; {@code false} otherwise 1285 * @see #selectBestTextFlavor 1286 * @since 1.4 1287 */ 1288 public boolean isFlavorTextType() { 1289 return (DataFlavorUtil.isFlavorCharsetTextType(this) || 1290 DataFlavorUtil.isFlavorNoncharsetTextType(this)); 1291 } 1292 1293 /** 1294 * Serializes this {@code DataFlavor}. 1295 */ 1296 public synchronized void writeExternal(ObjectOutput os) throws IOException { 1297 if (mimeType != null) { 1298 mimeType.setParameter("humanPresentableName", humanPresentableName); 1299 os.writeObject(mimeType); 1300 mimeType.removeParameter("humanPresentableName"); 1301 } else { 1302 os.writeObject(null); 1303 } 1304 1305 os.writeObject(representationClass); 1306 } 1307 1308 /** 1309 * Restores this {@code DataFlavor} from a Serialized state. 1310 */ 1311 public synchronized void readExternal(ObjectInput is) throws IOException , ClassNotFoundException { 1312 String rcn = null; 1313 mimeType = (MimeType)is.readObject(); 1314 1315 if (mimeType != null) { 1316 humanPresentableName = 1317 mimeType.getParameter("humanPresentableName"); 1318 mimeType.removeParameter("humanPresentableName"); 1319 rcn = mimeType.getParameter("class"); 1320 if (rcn == null) { 1321 throw new IOException("no class parameter specified in: " + 1322 mimeType); 1323 } 1324 } 1325 1326 try { 1327 representationClass = (Class)is.readObject(); 1328 } catch (OptionalDataException ode) { 1329 if (!ode.eof || ode.length != 0) { 1330 throw ode; 1331 } 1332 // Ensure backward compatibility. 1333 // Old versions didn't write the representation class to the stream. 1334 if (rcn != null) { 1335 representationClass = 1336 DataFlavor.tryToLoadClass(rcn, getClass().getClassLoader()); 1337 } 1338 } 1339 } 1340 1341 /** 1342 * Returns a clone of this {@code DataFlavor}. 1343 * 1344 * @return a clone of this {@code DataFlavor} 1345 */ 1346 public Object clone() throws CloneNotSupportedException { 1347 Object newObj = super.clone(); 1348 if (mimeType != null) { 1349 ((DataFlavor)newObj).mimeType = (MimeType)mimeType.clone(); 1350 } 1351 return newObj; 1352 } // clone() 1353 1354 /** 1355 * Called on {@code DataFlavor} for every MIME Type parameter to allow 1356 * {@code DataFlavor} subclasses to handle special parameters like the 1357 * text/plain {@code charset} parameters, whose values are case insensitive. 1358 * (MIME type parameter values are supposed to be case sensitive. 1359 * <p> 1360 * This method is called for each parameter name/value pair and should 1361 * return the normalized representation of the {@code parameterValue}. 1362 * 1363 * @param parameterName the parameter name 1364 * @param parameterValue the parameter value 1365 * @return the parameter value 1366 * @deprecated This method is never invoked by this implementation from 1.1 1367 * onwards 1368 */ 1369 @Deprecated 1370 protected String normalizeMimeTypeParameter(String parameterName, String parameterValue) { 1371 return parameterValue; 1372 } 1373 1374 /** 1375 * Called for each MIME type string to give {@code DataFlavor} subtypes the 1376 * opportunity to change how the normalization of MIME types is 1377 * accomplished. One possible use would be to add default parameter/value 1378 * pairs in cases where none are present in the MIME type string passed in. 1379 * 1380 * @param mimeType the mime type 1381 * @return the mime type 1382 * @deprecated This method is never invoked by this implementation from 1.1 1383 * onwards 1384 */ 1385 @Deprecated 1386 protected String normalizeMimeType(String mimeType) { 1387 return mimeType; 1388 } 1389 1390 /* 1391 * fields 1392 */ 1393 1394 /* placeholder for caching any platform-specific data for flavor */ 1395 1396 transient int atom; 1397 1398 /* Mime Type of DataFlavor */ 1399 1400 MimeType mimeType; 1401 1402 private String humanPresentableName; 1403 1404 /** 1405 * Java class of objects this DataFlavor represents. 1406 **/ 1407 private Class<?> representationClass; 1408 1409 } // class DataFlavor