001 /* MessageFormat.java - Localized message formatting. 002 Copyright (C) 1999, 2001, 2002, 2004, 2005 Free Software Foundation, Inc. 003 004 This file is part of GNU Classpath. 005 006 GNU Classpath is free software; you can redistribute it and/or modify 007 it under the terms of the GNU General Public License as published by 008 the Free Software Foundation; either version 2, or (at your option) 009 any later version. 010 011 GNU Classpath is distributed in the hope that it will be useful, but 012 WITHOUT ANY WARRANTY; without even the implied warranty of 013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014 General Public License for more details. 015 016 You should have received a copy of the GNU General Public License 017 along with GNU Classpath; see the file COPYING. If not, write to the 018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 019 02110-1301 USA. 020 021 Linking this library statically or dynamically with other modules is 022 making a combined work based on this library. Thus, the terms and 023 conditions of the GNU General Public License cover the whole 024 combination. 025 026 As a special exception, the copyright holders of this library give you 027 permission to link this library with independent modules to produce an 028 executable, regardless of the license terms of these independent 029 modules, and to copy and distribute the resulting executable under 030 terms of your choice, provided that you also meet, for each linked 031 independent module, the terms and conditions of the license of that 032 module. An independent module is a module which is not derived from 033 or based on this library. If you modify this library, you may extend 034 this exception to your version of the library, but you are not 035 obligated to do so. If you do not wish to do so, delete this 036 exception statement from your version. */ 037 038 039 package java.text; 040 041 import gnu.java.lang.CPStringBuilder; 042 043 import gnu.java.text.FormatCharacterIterator; 044 045 import java.io.InvalidObjectException; 046 047 import java.util.ArrayList; 048 import java.util.Date; 049 import java.util.HashMap; 050 import java.util.List; 051 import java.util.Locale; 052 053 public class MessageFormat extends Format 054 { 055 /** 056 * @author Tom Tromey (tromey@cygnus.com) 057 * @author Jorge Aliss (jaliss@hotmail.com) 058 * @date March 3, 1999 059 */ 060 /* Written using "Java Class Libraries", 2nd edition, plus online 061 * API docs for JDK 1.2 from http://www.javasoft.com. 062 * Status: Believed complete and correct to 1.2, except serialization. 063 * and parsing. 064 */ 065 private static final class MessageFormatElement 066 { 067 // Argument number. 068 int argNumber; 069 // Formatter to be used. This is the format set by setFormat. 070 Format setFormat; 071 // Formatter to be used based on the type. 072 Format format; 073 074 // Argument will be checked to make sure it is an instance of this 075 // class. 076 Class<?> formatClass; 077 078 // Formatter type. 079 String type; 080 // Formatter style. 081 String style; 082 083 // Text to follow this element. 084 String trailer; 085 086 // Recompute the locale-based formatter. 087 void setLocale (Locale loc) 088 { 089 if (type != null) 090 { 091 if (type.equals("number")) 092 { 093 formatClass = java.lang.Number.class; 094 095 if (style == null) 096 format = NumberFormat.getInstance(loc); 097 else if (style.equals("currency")) 098 format = NumberFormat.getCurrencyInstance(loc); 099 else if (style.equals("percent")) 100 format = NumberFormat.getPercentInstance(loc); 101 else if (style.equals("integer")) 102 format = NumberFormat.getIntegerInstance(loc); 103 else 104 { 105 format = NumberFormat.getNumberInstance(loc); 106 DecimalFormat df = (DecimalFormat) format; 107 df.applyPattern(style); 108 } 109 } 110 else if (type.equals("time") || type.equals("date")) 111 { 112 formatClass = java.util.Date.class; 113 114 int val = DateFormat.DEFAULT; 115 boolean styleIsPattern = false; 116 if (style != null) 117 { 118 if (style.equals("short")) 119 val = DateFormat.SHORT; 120 else if (style.equals("medium")) 121 val = DateFormat.MEDIUM; 122 else if (style.equals("long")) 123 val = DateFormat.LONG; 124 else if (style.equals("full")) 125 val = DateFormat.FULL; 126 else 127 styleIsPattern = true; 128 } 129 130 if (type.equals("time")) 131 format = DateFormat.getTimeInstance(val, loc); 132 else 133 format = DateFormat.getDateInstance(val, loc); 134 135 if (styleIsPattern) 136 { 137 SimpleDateFormat sdf = (SimpleDateFormat) format; 138 sdf.applyPattern(style); 139 } 140 } 141 else if (type.equals("choice")) 142 { 143 formatClass = java.lang.Number.class; 144 145 if (style == null) 146 throw new 147 IllegalArgumentException ("style required for choice format"); 148 format = new ChoiceFormat (style); 149 } 150 } 151 } 152 } 153 154 private static final long serialVersionUID = 6479157306784022952L; 155 156 public static class Field extends Format.Field 157 { 158 static final long serialVersionUID = 7899943957617360810L; 159 160 /** 161 * This is the attribute set for all characters produced 162 * by MessageFormat during a formatting. 163 */ 164 public static final MessageFormat.Field ARGUMENT = new MessageFormat.Field("argument"); 165 166 // For deserialization 167 @SuppressWarnings("unused") 168 private Field() 169 { 170 super(""); 171 } 172 173 protected Field(String s) 174 { 175 super(s); 176 } 177 178 /** 179 * invoked to resolve the true static constant by 180 * comparing the deserialized object to know name. 181 * 182 * @return object constant 183 */ 184 protected Object readResolve() throws InvalidObjectException 185 { 186 if (getName().equals(ARGUMENT.getName())) 187 return ARGUMENT; 188 189 throw new InvalidObjectException("no such MessageFormat field called " + getName()); 190 } 191 192 } 193 194 // Helper that returns the text up to the next format opener. The 195 // text is put into BUFFER. Returns index of character after end of 196 // string. Throws IllegalArgumentException on error. 197 private static int scanString(String pat, int index, CPStringBuilder buffer) 198 { 199 int max = pat.length(); 200 buffer.setLength(0); 201 boolean quoted = false; 202 for (; index < max; ++index) 203 { 204 char c = pat.charAt(index); 205 if (quoted) 206 { 207 // In a quoted context, a single quote ends the quoting. 208 if (c == '\'') 209 quoted = false; 210 else 211 buffer.append(c); 212 } 213 // Check for '', which is a single quote. 214 else if (c == '\'' && index + 1 < max && pat.charAt(index + 1) == '\'') 215 { 216 buffer.append(c); 217 ++index; 218 } 219 else if (c == '\'') 220 { 221 // Start quoting. 222 quoted = true; 223 } 224 else if (c == '{') 225 break; 226 else 227 buffer.append(c); 228 } 229 // Note that we explicitly allow an unterminated quote. This is 230 // done for compatibility. 231 return index; 232 } 233 234 // This helper retrieves a single part of a format element. Returns 235 // the index of the terminating character. 236 private static int scanFormatElement(String pat, int index, 237 CPStringBuilder buffer, char term) 238 { 239 int max = pat.length(); 240 buffer.setLength(0); 241 int brace_depth = 1; 242 boolean quoted = false; 243 244 for (; index < max; ++index) 245 { 246 char c = pat.charAt(index); 247 // First see if we should turn off quoting. 248 if (quoted) 249 { 250 if (c == '\'') 251 quoted = false; 252 // In both cases we fall through to inserting the 253 // character here. 254 } 255 // See if we have just a plain quote to insert. 256 else if (c == '\'' && index + 1 < max 257 && pat.charAt(index + 1) == '\'') 258 { 259 buffer.append(c); 260 ++index; 261 } 262 // See if quoting should turn on. 263 else if (c == '\'') 264 quoted = true; 265 else if (c == '{') 266 ++brace_depth; 267 else if (c == '}') 268 { 269 if (--brace_depth == 0) 270 break; 271 } 272 // Check for TERM after braces, because TERM might be `}'. 273 else if (c == term) 274 break; 275 // All characters, including opening and closing quotes, are 276 // inserted here. 277 buffer.append(c); 278 } 279 return index; 280 } 281 282 // This is used to parse a format element and whatever non-format 283 // text might trail it. 284 private static int scanFormat(String pat, int index, CPStringBuilder buffer, 285 List<MessageFormatElement> elts, Locale locale) 286 { 287 MessageFormatElement mfe = new MessageFormatElement (); 288 elts.add(mfe); 289 290 int max = pat.length(); 291 292 // Skip the opening `{'. 293 ++index; 294 295 // Fetch the argument number. 296 index = scanFormatElement (pat, index, buffer, ','); 297 try 298 { 299 mfe.argNumber = Integer.parseInt(buffer.toString()); 300 } 301 catch (NumberFormatException nfx) 302 { 303 IllegalArgumentException iae = new IllegalArgumentException(pat); 304 iae.initCause(nfx); 305 throw iae; 306 } 307 308 // Extract the element format. 309 if (index < max && pat.charAt(index) == ',') 310 { 311 index = scanFormatElement (pat, index + 1, buffer, ','); 312 mfe.type = buffer.toString(); 313 314 // Extract the style. 315 if (index < max && pat.charAt(index) == ',') 316 { 317 index = scanFormatElement (pat, index + 1, buffer, '}'); 318 mfe.style = buffer.toString (); 319 } 320 } 321 322 // Advance past the last terminator. 323 if (index >= max || pat.charAt(index) != '}') 324 throw new IllegalArgumentException("Missing '}' at end of message format"); 325 ++index; 326 327 // Now fetch trailing string. 328 index = scanString (pat, index, buffer); 329 mfe.trailer = buffer.toString (); 330 331 mfe.setLocale(locale); 332 333 return index; 334 } 335 336 /** 337 * Applies the specified pattern to this MessageFormat. 338 * 339 * @param newPattern The Pattern 340 */ 341 public void applyPattern (String newPattern) 342 { 343 pattern = newPattern; 344 345 CPStringBuilder tempBuffer = new CPStringBuilder (); 346 347 int index = scanString (newPattern, 0, tempBuffer); 348 leader = tempBuffer.toString(); 349 350 List<MessageFormatElement> elts = new ArrayList<MessageFormatElement>(); 351 while (index < newPattern.length()) 352 index = scanFormat (newPattern, index, tempBuffer, elts, locale); 353 354 elements = elts.toArray(new MessageFormatElement[elts.size()]); 355 } 356 357 /** 358 * Overrides Format.clone() 359 */ 360 public Object clone () 361 { 362 MessageFormat c = (MessageFormat) super.clone (); 363 c.elements = (MessageFormatElement[]) elements.clone (); 364 return c; 365 } 366 367 /** 368 * Overrides Format.equals(Object obj) 369 */ 370 public boolean equals (Object obj) 371 { 372 if (! (obj instanceof MessageFormat)) 373 return false; 374 MessageFormat mf = (MessageFormat) obj; 375 return (pattern.equals(mf.pattern) 376 && locale.equals(mf.locale)); 377 } 378 379 /** 380 * A convinience method to format patterns. 381 * 382 * @param arguments The array containing the objects to be formatted. 383 */ 384 public AttributedCharacterIterator formatToCharacterIterator (Object arguments) 385 { 386 Object[] arguments_array = (Object[])arguments; 387 FormatCharacterIterator iterator = new FormatCharacterIterator(); 388 389 formatInternal(arguments_array, new StringBuffer(), null, iterator); 390 391 return iterator; 392 } 393 394 /** 395 * A convinience method to format patterns. 396 * 397 * @param pattern The pattern used when formatting. 398 * @param arguments The array containing the objects to be formatted. 399 */ 400 public static String format (String pattern, Object... arguments) 401 { 402 MessageFormat mf = new MessageFormat (pattern); 403 StringBuffer sb = new StringBuffer (); 404 FieldPosition fp = new FieldPosition (NumberFormat.INTEGER_FIELD); 405 return mf.formatInternal(arguments, sb, fp, null).toString(); 406 } 407 408 /** 409 * Returns the pattern with the formatted objects. 410 * 411 * @param arguments The array containing the objects to be formatted. 412 * @param appendBuf The StringBuffer where the text is appened. 413 * @param fp A FieldPosition object (it is ignored). 414 */ 415 public final StringBuffer format (Object arguments[], StringBuffer appendBuf, 416 FieldPosition fp) 417 { 418 return formatInternal(arguments, appendBuf, fp, null); 419 } 420 421 private StringBuffer formatInternal (Object arguments[], 422 StringBuffer appendBuf, 423 FieldPosition fp, 424 FormatCharacterIterator output_iterator) 425 { 426 appendBuf.append(leader); 427 if (output_iterator != null) 428 output_iterator.append(leader); 429 430 for (int i = 0; i < elements.length; ++i) 431 { 432 Object thisArg = null; 433 boolean unavailable = false; 434 if (arguments == null || elements[i].argNumber >= arguments.length) 435 unavailable = true; 436 else 437 thisArg = arguments[elements[i].argNumber]; 438 439 AttributedCharacterIterator iterator = null; 440 441 Format formatter = null; 442 443 if (fp != null && i == fp.getField() && fp.getFieldAttribute() == Field.ARGUMENT) 444 fp.setBeginIndex(appendBuf.length()); 445 446 if (unavailable) 447 appendBuf.append("{" + elements[i].argNumber + "}"); 448 else 449 { 450 if (elements[i].setFormat != null) 451 formatter = elements[i].setFormat; 452 else if (elements[i].format != null) 453 { 454 if (elements[i].formatClass != null 455 && ! elements[i].formatClass.isInstance(thisArg)) 456 throw new IllegalArgumentException("Wrong format class"); 457 458 formatter = elements[i].format; 459 } 460 else if (thisArg instanceof Number) 461 formatter = NumberFormat.getInstance(locale); 462 else if (thisArg instanceof Date) 463 formatter = DateFormat.getTimeInstance(DateFormat.DEFAULT, locale); 464 else 465 appendBuf.append(thisArg); 466 } 467 468 if (fp != null && fp.getField() == i && fp.getFieldAttribute() == Field.ARGUMENT) 469 fp.setEndIndex(appendBuf.length()); 470 471 if (formatter != null) 472 { 473 // Special-case ChoiceFormat. 474 if (formatter instanceof ChoiceFormat) 475 { 476 StringBuffer buf = new StringBuffer (); 477 formatter.format(thisArg, buf, fp); 478 MessageFormat mf = new MessageFormat (); 479 mf.setLocale(locale); 480 mf.applyPattern(buf.toString()); 481 mf.format(arguments, appendBuf, fp); 482 } 483 else 484 { 485 if (output_iterator != null) 486 iterator = formatter.formatToCharacterIterator(thisArg); 487 else 488 formatter.format(thisArg, appendBuf, fp); 489 } 490 491 elements[i].format = formatter; 492 } 493 494 if (output_iterator != null) 495 { 496 HashMap<MessageFormat.Field, Integer> hash_argument = 497 new HashMap<MessageFormat.Field, Integer>(); 498 int position = output_iterator.getEndIndex(); 499 500 hash_argument.put (MessageFormat.Field.ARGUMENT, 501 Integer.valueOf(elements[i].argNumber)); 502 503 504 if (iterator != null) 505 { 506 output_iterator.append(iterator); 507 output_iterator.addAttributes(hash_argument, position, 508 output_iterator.getEndIndex()); 509 } 510 else 511 output_iterator.append(thisArg.toString(), hash_argument); 512 513 output_iterator.append(elements[i].trailer); 514 } 515 516 appendBuf.append(elements[i].trailer); 517 } 518 519 return appendBuf; 520 } 521 522 /** 523 * Returns the pattern with the formatted objects. The first argument 524 * must be a array of Objects. 525 * This is equivalent to format((Object[]) objectArray, appendBuf, fpos) 526 * 527 * @param objectArray The object array to be formatted. 528 * @param appendBuf The StringBuffer where the text is appened. 529 * @param fpos A FieldPosition object (it is ignored). 530 */ 531 public final StringBuffer format (Object objectArray, StringBuffer appendBuf, 532 FieldPosition fpos) 533 { 534 return format ((Object[])objectArray, appendBuf, fpos); 535 } 536 537 /** 538 * Returns an array with the Formats for 539 * the arguments. 540 */ 541 public Format[] getFormats () 542 { 543 Format[] f = new Format[elements.length]; 544 for (int i = elements.length - 1; i >= 0; --i) 545 f[i] = elements[i].setFormat; 546 return f; 547 } 548 549 /** 550 * Returns the locale. 551 */ 552 public Locale getLocale () 553 { 554 return locale; 555 } 556 557 /** 558 * Overrides Format.hashCode() 559 */ 560 public int hashCode () 561 { 562 // FIXME: not a very good hash. 563 return pattern.hashCode() + locale.hashCode(); 564 } 565 566 private MessageFormat () 567 { 568 } 569 570 /** 571 * Creates a new MessageFormat object with 572 * the specified pattern 573 * 574 * @param pattern The Pattern 575 */ 576 public MessageFormat(String pattern) 577 { 578 this(pattern, Locale.getDefault()); 579 } 580 581 /** 582 * Creates a new MessageFormat object with 583 * the specified pattern 584 * 585 * @param pattern The Pattern 586 * @param locale The Locale to use 587 * 588 * @since 1.4 589 */ 590 public MessageFormat(String pattern, Locale locale) 591 { 592 this.locale = locale; 593 applyPattern (pattern); 594 } 595 596 /** 597 * Parse a string <code>sourceStr</code> against the pattern specified 598 * to the MessageFormat constructor. 599 * 600 * @param sourceStr the string to be parsed. 601 * @param pos the current parse position (and eventually the error position). 602 * @return the array of parsed objects sorted according to their argument number 603 * in the pattern. 604 */ 605 public Object[] parse (String sourceStr, ParsePosition pos) 606 { 607 // Check initial text. 608 int index = pos.getIndex(); 609 if (! sourceStr.startsWith(leader, index)) 610 { 611 pos.setErrorIndex(index); 612 return null; 613 } 614 index += leader.length(); 615 616 ArrayList<Object> results = new ArrayList<Object>(elements.length); 617 // Now check each format. 618 for (int i = 0; i < elements.length; ++i) 619 { 620 Format formatter = null; 621 if (elements[i].setFormat != null) 622 formatter = elements[i].setFormat; 623 else if (elements[i].format != null) 624 formatter = elements[i].format; 625 626 Object value = null; 627 if (formatter instanceof ChoiceFormat) 628 { 629 // We must special-case a ChoiceFormat because it might 630 // have recursive formatting. 631 ChoiceFormat cf = (ChoiceFormat) formatter; 632 String[] formats = (String[]) cf.getFormats(); 633 double[] limits = cf.getLimits(); 634 MessageFormat subfmt = new MessageFormat (); 635 subfmt.setLocale(locale); 636 ParsePosition subpos = new ParsePosition (index); 637 638 int j; 639 for (j = 0; value == null && j < limits.length; ++j) 640 { 641 subfmt.applyPattern(formats[j]); 642 subpos.setIndex(index); 643 value = subfmt.parse(sourceStr, subpos); 644 } 645 if (value != null) 646 { 647 index = subpos.getIndex(); 648 value = new Double (limits[j]); 649 } 650 } 651 else if (formatter != null) 652 { 653 pos.setIndex(index); 654 value = formatter.parseObject(sourceStr, pos); 655 if (value != null) 656 index = pos.getIndex(); 657 } 658 else 659 { 660 // We have a String format. This can lose in a number 661 // of ways, but we give it a shot. 662 int next_index; 663 if (elements[i].trailer.length() > 0) 664 next_index = sourceStr.indexOf(elements[i].trailer, index); 665 else 666 next_index = sourceStr.length(); 667 if (next_index == -1) 668 { 669 pos.setErrorIndex(index); 670 return null; 671 } 672 value = sourceStr.substring(index, next_index); 673 index = next_index; 674 } 675 676 if (value == null 677 || ! sourceStr.startsWith(elements[i].trailer, index)) 678 { 679 pos.setErrorIndex(index); 680 return null; 681 } 682 683 if (elements[i].argNumber >= results.size()) 684 { 685 // Emulate padding behaviour of Vector.setSize() with ArrayList 686 results.ensureCapacity(elements[i].argNumber + 1); 687 for (int a = results.size(); a <= elements[i].argNumber; ++a) 688 results.add(a, null); 689 } 690 results.set(elements[i].argNumber, value); 691 692 index += elements[i].trailer.length(); 693 } 694 695 return results.toArray(new Object[results.size()]); 696 } 697 698 public Object[] parse (String sourceStr) throws ParseException 699 { 700 ParsePosition pp = new ParsePosition (0); 701 Object[] r = parse (sourceStr, pp); 702 if (r == null) 703 throw new ParseException ("couldn't parse string", pp.getErrorIndex()); 704 return r; 705 } 706 707 public Object parseObject (String sourceStr, ParsePosition pos) 708 { 709 return parse (sourceStr, pos); 710 } 711 712 /** 713 * Sets the format for the argument at an specified 714 * index. 715 * 716 * @param variableNum The index. 717 * @param newFormat The Format object. 718 */ 719 public void setFormat (int variableNum, Format newFormat) 720 { 721 elements[variableNum].setFormat = newFormat; 722 } 723 724 /** 725 * Sets the formats for the arguments. 726 * 727 * @param newFormats An array of Format objects. 728 */ 729 public void setFormats (Format[] newFormats) 730 { 731 if (newFormats.length < elements.length) 732 throw new IllegalArgumentException("Not enough format objects"); 733 734 int len = Math.min(newFormats.length, elements.length); 735 for (int i = 0; i < len; ++i) 736 elements[i].setFormat = newFormats[i]; 737 } 738 739 /** 740 * Sets the locale. 741 * 742 * @param loc A Locale 743 */ 744 public void setLocale (Locale loc) 745 { 746 locale = loc; 747 if (elements != null) 748 { 749 for (int i = 0; i < elements.length; ++i) 750 elements[i].setLocale(loc); 751 } 752 } 753 754 /** 755 * Returns the pattern. 756 */ 757 public String toPattern () 758 { 759 return pattern; 760 } 761 762 /** 763 * Return the formatters used sorted by argument index. It uses the 764 * internal table to fill in this array: if a format has been 765 * set using <code>setFormat</code> or <code>setFormatByArgumentIndex</code> 766 * then it returns it at the right index. If not it uses the detected 767 * formatters during a <code>format</code> call. If nothing is known 768 * about that argument index it just puts null at that position. 769 * To get useful informations you may have to call <code>format</code> 770 * at least once. 771 * 772 * @return an array of formatters sorted by argument index. 773 */ 774 public Format[] getFormatsByArgumentIndex() 775 { 776 int argNumMax = 0; 777 // First, find the greatest argument number. 778 for (int i=0;i<elements.length;i++) 779 if (elements[i].argNumber > argNumMax) 780 argNumMax = elements[i].argNumber; 781 782 Format[] formats = new Format[argNumMax]; 783 for (int i=0;i<elements.length;i++) 784 { 785 if (elements[i].setFormat != null) 786 formats[elements[i].argNumber] = elements[i].setFormat; 787 else if (elements[i].format != null) 788 formats[elements[i].argNumber] = elements[i].format; 789 } 790 return formats; 791 } 792 793 /** 794 * Set the format to used using the argument index number. 795 * 796 * @param argumentIndex the argument index. 797 * @param newFormat the format to use for this argument. 798 */ 799 public void setFormatByArgumentIndex(int argumentIndex, 800 Format newFormat) 801 { 802 for (int i=0;i<elements.length;i++) 803 { 804 if (elements[i].argNumber == argumentIndex) 805 elements[i].setFormat = newFormat; 806 } 807 } 808 809 /** 810 * Set the format for argument using a specified array of formatters 811 * which is sorted according to the argument index. If the number of 812 * elements in the array is fewer than the number of arguments only 813 * the arguments specified by the array are touched. 814 * 815 * @param newFormats array containing the new formats to set. 816 * 817 * @throws NullPointerException if newFormats is null 818 */ 819 public void setFormatsByArgumentIndex(Format[] newFormats) 820 { 821 for (int i=0;i<newFormats.length;i++) 822 { 823 // Nothing better than that can exist here. 824 setFormatByArgumentIndex(i, newFormats[i]); 825 } 826 } 827 828 // The pattern string. 829 private String pattern; 830 // The locale. 831 private Locale locale; 832 // Variables. 833 private MessageFormatElement[] elements; 834 // Leader text. 835 private String leader; 836 }