libjava/external/sax/org/xml/sax/helpers/AttributesImpl.java

   1 // AttributesImpl.java - default implementation of Attributes.
   2 // http://www.saxproject.org
   3 // Written by David Megginson
   4 // NO WARRANTY!  This class is in the public domain.
   5 // $Id: AttributesImpl.java,v 1.1 2005/02/02 00:41:54 tromey Exp $
   6
   7 package org.xml.sax.helpers;
   8
   9 import org.xml.sax.Attributes;
  10
  11
  12 /**
  13  * Default implementation of the Attributes interface.
  14  *
  15  * <blockquote>
  16  * <em>This module, both source code and documentation, is in the
  17  * Public Domain, and comes with <strong>NO WARRANTY</strong>.</em>
  18  * See <a href='http://www.saxproject.org'>http://www.saxproject.org</a>
  19  * for further information.
  20  * </blockquote>
  21  *
  22  * <p>This class provides a default implementation of the SAX2
  23  * {@link org.xml.sax.Attributes Attributes} interface, with the
  24  * addition of manipulators so that the list can be modified or
  25  * reused.</p>
  26  *
  27  * <p>There are two typical uses of this class:</p>
  28  *
  29  * <ol>
  30  * <li>to take a persistent snapshot of an Attributes object
  31  *  in a {@link org.xml.sax.ContentHandler#startElement startElement} event; or</li>
  32  * <li>to construct or modify an Attributes object in a SAX2 driver or filter.</li>
  33  * </ol>
  34  *
  35  * <p>This class replaces the now-deprecated SAX1 {@link
  36  * org.xml.sax.helpers.AttributeListImpl AttributeListImpl}
  37  * class; in addition to supporting the updated Attributes
  38  * interface rather than the deprecated {@link org.xml.sax.AttributeList
  39  * AttributeList} interface, it also includes a much more efficient
  40  * implementation using a single array rather than a set of Vectors.</p>
  41  *
  42  * @since SAX 2.0
  43  * @author David Megginson
  44  * @version 2.0.1 (sax2r2)
  45  */
  46 public class AttributesImpl implements Attributes
  47 {
  48
  49 \f
  50     ////////////////////////////////////////////////////////////////////
  51     // Constructors.
  52     ////////////////////////////////////////////////////////////////////
  53
  54
  55     /**
  56      * Construct a new, empty AttributesImpl object.
  57      */
  58     public AttributesImpl ()
  59     {
  60         length = 0;
  61         data = null;
  62     }
  63
  64
  65     /**
  66      * Copy an existing Attributes object.
  67      *
  68      * <p>This constructor is especially useful inside a
  69      * {@link org.xml.sax.ContentHandler#startElement startElement} event.</p>
  70      *
  71      * @param atts The existing Attributes object.
  72      */
  73     public AttributesImpl (Attributes atts)
  74     {
  75         setAttributes(atts);
  76     }
  77
  78
  79 \f
  80     ////////////////////////////////////////////////////////////////////
  81     // Implementation of org.xml.sax.Attributes.
  82     ////////////////////////////////////////////////////////////////////
  83
  84
  85     /**
  86      * Return the number of attributes in the list.
  87      *
  88      * @return The number of attributes in the list.
  89      * @see org.xml.sax.Attributes#getLength
  90      */
  91     public int getLength ()
  92     {
  93         return length;
  94     }
  95
  96
  97     /**
  98      * Return an attribute's Namespace URI.
  99      *
 100      * @param index The attribute's index (zero-based).
 101      * @return The Namespace URI, the empty string if none is
 102      *         available, or null if the index is out of range.
 103      * @see org.xml.sax.Attributes#getURI
 104      */
 105     public String getURI (int index)
 106     {
 107         if (index >= 0 && index < length) {
 108             return data[index*5];
 109         } else {
 110             return null;
 111         }
 112     }
 113
 114
 115     /**
 116      * Return an attribute's local name.
 117      *
 118      * @param index The attribute's index (zero-based).
 119      * @return The attribute's local name, the empty string if
 120      *         none is available, or null if the index if out of range.
 121      * @see org.xml.sax.Attributes#getLocalName
 122      */
 123     public String getLocalName (int index)
 124     {
 125         if (index >= 0 && index < length) {
 126             return data[index*5+1];
 127         } else {
 128             return null;
 129         }
 130     }
 131
 132
 133     /**
 134      * Return an attribute's qualified (prefixed) name.
 135      *
 136      * @param index The attribute's index (zero-based).
 137      * @return The attribute's qualified name, the empty string if
 138      *         none is available, or null if the index is out of bounds.
 139      * @see org.xml.sax.Attributes#getQName
 140      */
 141     public String getQName (int index)
 142     {
 143         if (index >= 0 && index < length) {
 144             return data[index*5+2];
 145         } else {
 146             return null;
 147         }
 148     }
 149
 150
 151     /**
 152      * Return an attribute's type by index.
 153      *
 154      * @param index The attribute's index (zero-based).
 155      * @return The attribute's type, "CDATA" if the type is unknown, or null
 156      *         if the index is out of bounds.
 157      * @see org.xml.sax.Attributes#getType(int)
 158      */
 159     public String getType (int index)
 160     {
 161         if (index >= 0 && index < length) {
 162             return data[index*5+3];
 163         } else {
 164             return null;
 165         }
 166     }
 167
 168
 169     /**
 170      * Return an attribute's value by index.
 171      *
 172      * @param index The attribute's index (zero-based).
 173      * @return The attribute's value or null if the index is out of bounds.
 174      * @see org.xml.sax.Attributes#getValue(int)
 175      */
 176     public String getValue (int index)
 177     {
 178         if (index >= 0 && index < length) {
 179             return data[index*5+4];
 180         } else {
 181             return null;
 182         }
 183     }
 184
 185
 186     /**
 187      * Look up an attribute's index by Namespace name.
 188      *
 189      * <p>In many cases, it will be more efficient to look up the name once and
 190      * use the index query methods rather than using the name query methods
 191      * repeatedly.</p>
 192      *
 193      * @param uri The attribute's Namespace URI, or the empty
 194      *        string if none is available.
 195      * @param localName The attribute's local name.
 196      * @return The attribute's index, or -1 if none matches.
 197      * @see org.xml.sax.Attributes#getIndex(java.lang.String,java.lang.String)
 198      */
 199     public int getIndex (String uri, String localName)
 200     {
 201         int max = length * 5;
 202         for (int i = 0; i < max; i += 5) {
 203             if (data[i].equals(uri) && data[i+1].equals(localName)) {
 204                 return i / 5;
 205             }
 206         }
 207         return -1;
 208     }
 209
 210
 211     /**
 212      * Look up an attribute's index by qualified (prefixed) name.
 213      *
 214      * @param qName The qualified name.
 215      * @return The attribute's index, or -1 if none matches.
 216      * @see org.xml.sax.Attributes#getIndex(java.lang.String)
 217      */
 218     public int getIndex (String qName)
 219     {
 220         int max = length * 5;
 221         for (int i = 0; i < max; i += 5) {
 222             if (data[i+2].equals(qName)) {
 223                 return i / 5;
 224             }
 225         }
 226         return -1;
 227     }
 228
 229
 230     /**
 231      * Look up an attribute's type by Namespace-qualified name.
 232      *
 233      * @param uri The Namespace URI, or the empty string for a name
 234      *        with no explicit Namespace URI.
 235      * @param localName The local name.
 236      * @return The attribute's type, or null if there is no
 237      *         matching attribute.
 238      * @see org.xml.sax.Attributes#getType(java.lang.String,java.lang.String)
 239      */
 240     public String getType (String uri, String localName)
 241     {
 242         int max = length * 5;
 243         for (int i = 0; i < max; i += 5) {
 244             if (data[i].equals(uri) && data[i+1].equals(localName)) {
 245                 return data[i+3];
 246             }
 247         }
 248         return null;
 249     }
 250
 251
 252     /**
 253      * Look up an attribute's type by qualified (prefixed) name.
 254      *
 255      * @param qName The qualified name.
 256      * @return The attribute's type, or null if there is no
 257      *         matching attribute.
 258      * @see org.xml.sax.Attributes#getType(java.lang.String)
 259      */
 260     public String getType (String qName)
 261     {
 262         int max = length * 5;
 263         for (int i = 0; i < max; i += 5) {
 264             if (data[i+2].equals(qName)) {
 265                 return data[i+3];
 266             }
 267         }
 268         return null;
 269     }
 270
 271
 272     /**
 273      * Look up an attribute's value by Namespace-qualified name.
 274      *
 275      * @param uri The Namespace URI, or the empty string for a name
 276      *        with no explicit Namespace URI.
 277      * @param localName The local name.
 278      * @return The attribute's value, or null if there is no
 279      *         matching attribute.
 280      * @see org.xml.sax.Attributes#getValue(java.lang.String,java.lang.String)
 281      */
 282     public String getValue (String uri, String localName)
 283     {
 284         int max = length * 5;
 285         for (int i = 0; i < max; i += 5) {
 286             if (data[i].equals(uri) && data[i+1].equals(localName)) {
 287                 return data[i+4];
 288             }
 289         }
 290         return null;
 291     }
 292
 293
 294     /**
 295      * Look up an attribute's value by qualified (prefixed) name.
 296      *
 297      * @param qName The qualified name.
 298      * @return The attribute's value, or null if there is no
 299      *         matching attribute.
 300      * @see org.xml.sax.Attributes#getValue(java.lang.String)
 301      */
 302     public String getValue (String qName)
 303     {
 304         int max = length * 5;
 305         for (int i = 0; i < max; i += 5) {
 306             if (data[i+2].equals(qName)) {
 307                 return data[i+4];
 308             }
 309         }
 310         return null;
 311     }
 312
 313
 314 \f
 315     ////////////////////////////////////////////////////////////////////
 316     // Manipulators.
 317     ////////////////////////////////////////////////////////////////////
 318
 319
 320     /**
 321      * Clear the attribute list for reuse.
 322      *
 323      * <p>Note that little memory is freed by this call:
 324      * the current array is kept so it can be
 325      * reused.</p>
 326      */
 327     public void clear ()
 328     {
 329         if (data != null) {
 330             for (int i = 0; i < (length * 5); i++)
 331                 data [i] = null;
 332         }
 333         length = 0;
 334     }
 335
 336
 337     /**
 338      * Copy an entire Attributes object.
 339      *
 340      * <p>It may be more efficient to reuse an existing object
 341      * rather than constantly allocating new ones.</p>
 342      *
 343      * @param atts The attributes to copy.
 344      */
 345     public void setAttributes (Attributes atts)
 346     {
 347         clear();
 348         length = atts.getLength();
 349         if (length > 0) {
 350             data = new String[length*5];
 351             for (int i = 0; i < length; i++) {
 352                 data[i*5] = atts.getURI(i);
 353                 data[i*5+1] = atts.getLocalName(i);
 354                 data[i*5+2] = atts.getQName(i);
 355                 data[i*5+3] = atts.getType(i);
 356                 data[i*5+4] = atts.getValue(i);
 357             }
 358         }
 359     }
 360
 361
 362     /**
 363      * Add an attribute to the end of the list.
 364      *
 365      * <p>For the sake of speed, this method does no checking
 366      * to see if the attribute is already in the list: that is
 367      * the responsibility of the application.</p>
 368      *
 369      * @param uri The Namespace URI, or the empty string if
 370      *        none is available or Namespace processing is not
 371      *        being performed.
 372      * @param localName The local name, or the empty string if
 373      *        Namespace processing is not being performed.
 374      * @param qName The qualified (prefixed) name, or the empty string
 375      *        if qualified names are not available.
 376      * @param type The attribute type as a string.
 377      * @param value The attribute value.
 378      */
 379     public void addAttribute (String uri, String localName, String qName,
 380                               String type, String value)
 381     {
 382         ensureCapacity(length+1);
 383         data[length*5] = uri;
 384         data[length*5+1] = localName;
 385         data[length*5+2] = qName;
 386         data[length*5+3] = type;
 387         data[length*5+4] = value;
 388         length++;
 389     }
 390
 391
 392     /**
 393      * Set an attribute in the list.
 394      *
 395      * <p>For the sake of speed, this method does no checking
 396      * for name conflicts or well-formedness: such checks are the
 397      * responsibility of the application.</p>
 398      *
 399      * @param index The index of the attribute (zero-based).
 400      * @param uri The Namespace URI, or the empty string if
 401      *        none is available or Namespace processing is not
 402      *        being performed.
 403      * @param localName The local name, or the empty string if
 404      *        Namespace processing is not being performed.
 405      * @param qName The qualified name, or the empty string
 406      *        if qualified names are not available.
 407      * @param type The attribute type as a string.
 408      * @param value The attribute value.
 409      * @exception java.lang.ArrayIndexOutOfBoundsException When the
 410      *            supplied index does not point to an attribute
 411      *            in the list.
 412      */
 413     public void setAttribute (int index, String uri, String localName,
 414                               String qName, String type, String value)
 415     {
 416         if (index >= 0 && index < length) {
 417             data[index*5] = uri;
 418             data[index*5+1] = localName;
 419             data[index*5+2] = qName;
 420             data[index*5+3] = type;
 421             data[index*5+4] = value;
 422         } else {
 423             badIndex(index);
 424         }
 425     }
 426
 427
 428     /**
 429      * Remove an attribute from the list.
 430      *
 431      * @param index The index of the attribute (zero-based).
 432      * @exception java.lang.ArrayIndexOutOfBoundsException When the
 433      *            supplied index does not point to an attribute
 434      *            in the list.
 435      */
 436     public void removeAttribute (int index)
 437     {
 438         if (index >= 0 && index < length) {
 439             if (index < length - 1) {
 440                 System.arraycopy(data, (index+1)*5, data, index*5,
 441                                  (length-index-1)*5);
 442             }
 443             index = (length - 1) * 5;
 444             data [index++] = null;
 445             data [index++] = null;
 446             data [index++] = null;
 447             data [index++] = null;
 448             data [index] = null;
 449             length--;
 450         } else {
 451             badIndex(index);
 452         }
 453     }
 454
 455
 456     /**
 457      * Set the Namespace URI of a specific attribute.
 458      *
 459      * @param index The index of the attribute (zero-based).
 460      * @param uri The attribute's Namespace URI, or the empty
 461      *        string for none.
 462      * @exception java.lang.ArrayIndexOutOfBoundsException When the
 463      *            supplied index does not point to an attribute
 464      *            in the list.
 465      */
 466     public void setURI (int index, String uri)
 467     {
 468         if (index >= 0 && index < length) {
 469             data[index*5] = uri;
 470         } else {
 471             badIndex(index);
 472         }
 473     }
 474
 475
 476     /**
 477      * Set the local name of a specific attribute.
 478      *
 479      * @param index The index of the attribute (zero-based).
 480      * @param localName The attribute's local name, or the empty
 481      *        string for none.
 482      * @exception java.lang.ArrayIndexOutOfBoundsException When the
 483      *            supplied index does not point to an attribute
 484      *            in the list.
 485      */
 486     public void setLocalName (int index, String localName)
 487     {
 488         if (index >= 0 && index < length) {
 489             data[index*5+1] = localName;
 490         } else {
 491             badIndex(index);
 492         }
 493     }
 494
 495
 496     /**
 497      * Set the qualified name of a specific attribute.
 498      *
 499      * @param index The index of the attribute (zero-based).
 500      * @param qName The attribute's qualified name, or the empty
 501      *        string for none.
 502      * @exception java.lang.ArrayIndexOutOfBoundsException When the
 503      *            supplied index does not point to an attribute
 504      *            in the list.
 505      */
 506     public void setQName (int index, String qName)
 507     {
 508         if (index >= 0 && index < length) {
 509             data[index*5+2] = qName;
 510         } else {
 511             badIndex(index);
 512         }
 513     }
 514
 515
 516     /**
 517      * Set the type of a specific attribute.
 518      *
 519      * @param index The index of the attribute (zero-based).
 520      * @param type The attribute's type.
 521      * @exception java.lang.ArrayIndexOutOfBoundsException When the
 522      *            supplied index does not point to an attribute
 523      *            in the list.
 524      */
 525     public void setType (int index, String type)
 526     {
 527         if (index >= 0 && index < length) {
 528             data[index*5+3] = type;
 529         } else {
 530             badIndex(index);
 531         }
 532     }
 533
 534
 535     /**
 536      * Set the value of a specific attribute.
 537      *
 538      * @param index The index of the attribute (zero-based).
 539      * @param value The attribute's value.
 540      * @exception java.lang.ArrayIndexOutOfBoundsException When the
 541      *            supplied index does not point to an attribute
 542      *            in the list.
 543      */
 544     public void setValue (int index, String value)
 545     {
 546         if (index >= 0 && index < length) {
 547             data[index*5+4] = value;
 548         } else {
 549             badIndex(index);
 550         }
 551     }
 552
 553
 554 \f
 555     ////////////////////////////////////////////////////////////////////
 556     // Internal methods.
 557     ////////////////////////////////////////////////////////////////////
 558
 559
 560     /**
 561      * Ensure the internal array's capacity.
 562      *
 563      * @param n The minimum number of attributes that the array must
 564      *        be able to hold.
 565      */
 566     private void ensureCapacity (int n)    {
 567         if (n <= 0) {
 568             return;
 569         }
 570         int max;
 571         if (data == null || data.length == 0) {
 572             max = 25;
 573         }
 574         else if (data.length >= n * 5) {
 575             return;
 576         }
 577         else {
 578             max = data.length;
 579         }
 580         while (max < n * 5) {
 581             max *= 2;
 582         }
 583
 584         String newData[] = new String[max];
 585         if (length > 0) {
 586             System.arraycopy(data, 0, newData, 0, length*5);
 587         }
 588         data = newData;
 589     }
 590
 591
 592     /**
 593      * Report a bad array index in a manipulator.
 594      *
 595      * @param index The index to report.
 596      * @exception java.lang.ArrayIndexOutOfBoundsException Always.
 597      */
 598     private void badIndex (int index)
 599         throws ArrayIndexOutOfBoundsException
 600     {
 601         String msg =
 602             "Attempt to modify attribute at illegal index: " + index;
 603         throw new ArrayIndexOutOfBoundsException(msg);
 604     }
 605
 606
 607 \f
 608     ////////////////////////////////////////////////////////////////////
 609     // Internal state.
 610     ////////////////////////////////////////////////////////////////////
 611
 612     int length;
 613     String data [];
 614
 615 }
 616
 617 // end of AttributesImpl.java
 618