| Frames | No Frames |
1: // SAX default handler base class. 2: // http://www.saxproject.org 3: // No warranty; no copyright -- use this as you will. 4: // $Id: HandlerBase.java,v 1.1 2004/12/23 22:38:42 mark Exp $ 5: 6: package org.xml.sax; 7: 8: /** 9: * Default base class for handlers. 10: * 11: * <blockquote> 12: * <em>This module, both source code and documentation, is in the 13: * Public Domain, and comes with <strong>NO WARRANTY</strong>.</em> 14: * See <a href='http://www.saxproject.org'>http://www.saxproject.org</a> 15: * for further information. 16: * </blockquote> 17: * 18: * <p>This class implements the default behaviour for four SAX1 19: * interfaces: EntityResolver, DTDHandler, DocumentHandler, 20: * and ErrorHandler. It is now obsolete, but is included in SAX2 to 21: * support legacy SAX1 applications. SAX2 applications should use 22: * the {@link org.xml.sax.helpers.DefaultHandler DefaultHandler} 23: * class instead.</p> 24: * 25: * <p>Application writers can extend this class when they need to 26: * implement only part of an interface; parser writers can 27: * instantiate this class to provide default handlers when the 28: * application has not supplied its own.</p> 29: * 30: * <p>Note that the use of this class is optional.</p> 31: * 32: * @deprecated This class works with the deprecated 33: * {@link org.xml.sax.DocumentHandler DocumentHandler} 34: * interface. It has been replaced by the SAX2 35: * {@link org.xml.sax.helpers.DefaultHandler DefaultHandler} 36: * class. 37: * @since SAX 1.0 38: * @author David Megginson 39: * @version 2.0.1 (sax2r2) 40: * @see org.xml.sax.EntityResolver 41: * @see org.xml.sax.DTDHandler 42: * @see org.xml.sax.DocumentHandler 43: * @see org.xml.sax.ErrorHandler 44: */ 45: public class HandlerBase 46: implements EntityResolver, DTDHandler, DocumentHandler, ErrorHandler 47: { 48: 49: 50: //////////////////////////////////////////////////////////////////// 51: // Default implementation of the EntityResolver interface. 52: //////////////////////////////////////////////////////////////////// 53: 54: /** 55: * Resolve an external entity. 56: * 57: * <p>Always return null, so that the parser will use the system 58: * identifier provided in the XML document. This method implements 59: * the SAX default behaviour: application writers can override it 60: * in a subclass to do special translations such as catalog lookups 61: * or URI redirection.</p> 62: * 63: * @param publicId The public identifer, or null if none is 64: * available. 65: * @param systemId The system identifier provided in the XML 66: * document. 67: * @return The new input source, or null to require the 68: * default behaviour. 69: * @exception org.xml.sax.SAXException Any SAX exception, possibly 70: * wrapping another exception. 71: * @see org.xml.sax.EntityResolver#resolveEntity 72: */ 73: public InputSource resolveEntity (String publicId, String systemId) 74: throws SAXException 75: { 76: return null; 77: } 78: 79: 80: 81: //////////////////////////////////////////////////////////////////// 82: // Default implementation of DTDHandler interface. 83: //////////////////////////////////////////////////////////////////// 84: 85: 86: /** 87: * Receive notification of a notation declaration. 88: * 89: * <p>By default, do nothing. Application writers may override this 90: * method in a subclass if they wish to keep track of the notations 91: * declared in a document.</p> 92: * 93: * @param name The notation name. 94: * @param publicId The notation public identifier, or null if not 95: * available. 96: * @param systemId The notation system identifier. 97: * @see org.xml.sax.DTDHandler#notationDecl 98: */ 99: public void notationDecl (String name, String publicId, String systemId) 100: { 101: // no op 102: } 103: 104: 105: /** 106: * Receive notification of an unparsed entity declaration. 107: * 108: * <p>By default, do nothing. Application writers may override this 109: * method in a subclass to keep track of the unparsed entities 110: * declared in a document.</p> 111: * 112: * @param name The entity name. 113: * @param publicId The entity public identifier, or null if not 114: * available. 115: * @param systemId The entity system identifier. 116: * @param notationName The name of the associated notation. 117: * @see org.xml.sax.DTDHandler#unparsedEntityDecl 118: */ 119: public void unparsedEntityDecl (String name, String publicId, 120: String systemId, String notationName) 121: { 122: // no op 123: } 124: 125: 126: 127: //////////////////////////////////////////////////////////////////// 128: // Default implementation of DocumentHandler interface. 129: //////////////////////////////////////////////////////////////////// 130: 131: 132: /** 133: * Receive a Locator object for document events. 134: * 135: * <p>By default, do nothing. Application writers may override this 136: * method in a subclass if they wish to store the locator for use 137: * with other document events.</p> 138: * 139: * @param locator A locator for all SAX document events. 140: * @see org.xml.sax.DocumentHandler#setDocumentLocator 141: * @see org.xml.sax.Locator 142: */ 143: public void setDocumentLocator (Locator locator) 144: { 145: // no op 146: } 147: 148: 149: /** 150: * Receive notification of the beginning of the document. 151: * 152: * <p>By default, do nothing. Application writers may override this 153: * method in a subclass to take specific actions at the beginning 154: * of a document (such as allocating the root node of a tree or 155: * creating an output file).</p> 156: * 157: * @exception org.xml.sax.SAXException Any SAX exception, possibly 158: * wrapping another exception. 159: * @see org.xml.sax.DocumentHandler#startDocument 160: */ 161: public void startDocument () 162: throws SAXException 163: { 164: // no op 165: } 166: 167: 168: /** 169: * Receive notification of the end of the document. 170: * 171: * <p>By default, do nothing. Application writers may override this 172: * method in a subclass to take specific actions at the beginning 173: * of a document (such as finalising a tree or closing an output 174: * file).</p> 175: * 176: * @exception org.xml.sax.SAXException Any SAX exception, possibly 177: * wrapping another exception. 178: * @see org.xml.sax.DocumentHandler#endDocument 179: */ 180: public void endDocument () 181: throws SAXException 182: { 183: // no op 184: } 185: 186: 187: /** 188: * Receive notification of the start of an element. 189: * 190: * <p>By default, do nothing. Application writers may override this 191: * method in a subclass to take specific actions at the start of 192: * each element (such as allocating a new tree node or writing 193: * output to a file).</p> 194: * 195: * @param name The element type name. 196: * @param attributes The specified or defaulted attributes. 197: * @exception org.xml.sax.SAXException Any SAX exception, possibly 198: * wrapping another exception. 199: * @see org.xml.sax.DocumentHandler#startElement 200: */ 201: public void startElement (String name, AttributeList attributes) 202: throws SAXException 203: { 204: // no op 205: } 206: 207: 208: /** 209: * Receive notification of the end of an element. 210: * 211: * <p>By default, do nothing. Application writers may override this 212: * method in a subclass to take specific actions at the end of 213: * each element (such as finalising a tree node or writing 214: * output to a file).</p> 215: * 216: * @param name the element name 217: * @exception org.xml.sax.SAXException Any SAX exception, possibly 218: * wrapping another exception. 219: * @see org.xml.sax.DocumentHandler#endElement 220: */ 221: public void endElement (String name) 222: throws SAXException 223: { 224: // no op 225: } 226: 227: 228: /** 229: * Receive notification of character data inside an element. 230: * 231: * <p>By default, do nothing. Application writers may override this 232: * method to take specific actions for each chunk of character data 233: * (such as adding the data to a node or buffer, or printing it to 234: * a file).</p> 235: * 236: * @param ch The characters. 237: * @param start The start position in the character array. 238: * @param length The number of characters to use from the 239: * character array. 240: * @exception org.xml.sax.SAXException Any SAX exception, possibly 241: * wrapping another exception. 242: * @see org.xml.sax.DocumentHandler#characters 243: */ 244: public void characters (char ch[], int start, int length) 245: throws SAXException 246: { 247: // no op 248: } 249: 250: 251: /** 252: * Receive notification of ignorable whitespace in element content. 253: * 254: * <p>By default, do nothing. Application writers may override this 255: * method to take specific actions for each chunk of ignorable 256: * whitespace (such as adding data to a node or buffer, or printing 257: * it to a file).</p> 258: * 259: * @param ch The whitespace characters. 260: * @param start The start position in the character array. 261: * @param length The number of characters to use from the 262: * character array. 263: * @exception org.xml.sax.SAXException Any SAX exception, possibly 264: * wrapping another exception. 265: * @see org.xml.sax.DocumentHandler#ignorableWhitespace 266: */ 267: public void ignorableWhitespace (char ch[], int start, int length) 268: throws SAXException 269: { 270: // no op 271: } 272: 273: 274: /** 275: * Receive notification of a processing instruction. 276: * 277: * <p>By default, do nothing. Application writers may override this 278: * method in a subclass to take specific actions for each 279: * processing instruction, such as setting status variables or 280: * invoking other methods.</p> 281: * 282: * @param target The processing instruction target. 283: * @param data The processing instruction data, or null if 284: * none is supplied. 285: * @exception org.xml.sax.SAXException Any SAX exception, possibly 286: * wrapping another exception. 287: * @see org.xml.sax.DocumentHandler#processingInstruction 288: */ 289: public void processingInstruction (String target, String data) 290: throws SAXException 291: { 292: // no op 293: } 294: 295: 296: 297: //////////////////////////////////////////////////////////////////// 298: // Default implementation of the ErrorHandler interface. 299: //////////////////////////////////////////////////////////////////// 300: 301: 302: /** 303: * Receive notification of a parser warning. 304: * 305: * <p>The default implementation does nothing. Application writers 306: * may override this method in a subclass to take specific actions 307: * for each warning, such as inserting the message in a log file or 308: * printing it to the console.</p> 309: * 310: * @param e The warning information encoded as an exception. 311: * @exception org.xml.sax.SAXException Any SAX exception, possibly 312: * wrapping another exception. 313: * @see org.xml.sax.ErrorHandler#warning 314: * @see org.xml.sax.SAXParseException 315: */ 316: public void warning (SAXParseException e) 317: throws SAXException 318: { 319: // no op 320: } 321: 322: 323: /** 324: * Receive notification of a recoverable parser error. 325: * 326: * <p>The default implementation does nothing. Application writers 327: * may override this method in a subclass to take specific actions 328: * for each error, such as inserting the message in a log file or 329: * printing it to the console.</p> 330: * 331: * @param e The warning information encoded as an exception. 332: * @exception org.xml.sax.SAXException Any SAX exception, possibly 333: * wrapping another exception. 334: * @see org.xml.sax.ErrorHandler#warning 335: * @see org.xml.sax.SAXParseException 336: */ 337: public void error (SAXParseException e) 338: throws SAXException 339: { 340: // no op 341: } 342: 343: 344: /** 345: * Report a fatal XML parsing error. 346: * 347: * <p>The default implementation throws a SAXParseException. 348: * Application writers may override this method in a subclass if 349: * they need to take specific actions for each fatal error (such as 350: * collecting all of the errors into a single report): in any case, 351: * the application must stop all regular processing when this 352: * method is invoked, since the document is no longer reliable, and 353: * the parser may no longer report parsing events.</p> 354: * 355: * @param e The error information encoded as an exception. 356: * @exception org.xml.sax.SAXException Any SAX exception, possibly 357: * wrapping another exception. 358: * @see org.xml.sax.ErrorHandler#fatalError 359: * @see org.xml.sax.SAXParseException 360: */ 361: public void fatalError (SAXParseException e) 362: throws SAXException 363: { 364: throw e; 365: } 366: 367: } 368: 369: // end of HandlerBase.java