1 // DefaultHandler2.java - extended DefaultHandler 2 // http://www.saxproject.org 3 // Public Domain: no warranty. 4 // $Id: DefaultHandler2.java,v 1.3 2002/01/12 19:04:19 dbrownell Exp $ 5 6 package org.xml.sax.ext; 7 8 import java.io.IOException; 9 import org.xml.sax.InputSource; 10 import org.xml.sax.SAXException; 11 import org.xml.sax.helpers.DefaultHandler; 12 13 14 /** 15 * This class extends the SAX2 base handler class to support the 16 * SAX2 {@link LexicalHandler}, {@link DeclHandler}, and 17 * {@link EntityResolver2} extensions. Except for overriding the 18 * original SAX1 {@link DefaultHandler#resolveEntity resolveEntity()} 19 * method the added handler methods just return. Subclassers may 20 * override everything on a method-by-method basis. 21 * 22 * <blockquote> 23 * <em>This module, both source code and documentation, is in the 24 * Public Domain, and comes with <strong>NO WARRANTY</strong>.</em> 25 * </blockquote> 26 * 27 * <p> <em>Note:</em> this class might yet learn that the 28 * <em>ContentHandler.setDocumentLocator()</em> call might be passed a 29 * {@link Locator2} object, and that the 30 * <em>ContentHandler.startElement()</em> call might be passed a 31 * {@link Attributes2} object. 32 * 33 * @since SAX 2.0 (extensions 1.1 alpha) 34 * @author David Brownell 35 * @version TBS 36 */ 37 public class DefaultHandler2 extends DefaultHandler 38 implements LexicalHandler, DeclHandler, EntityResolver2 39 { 40 /** Constructs a handler which ignores all parsing events. */ 41 public DefaultHandler2 () { } 42 43 44 // SAX2 ext-1.0 LexicalHandler 45 46 public void startCDATA () 47 throws SAXException 48 {} 49 50 public void endCDATA () 51 throws SAXException 52 {} 53 54 public void startDTD (String name, String publicId, String systemId) 55 throws SAXException 56 {} 57 58 public void endDTD () 59 throws SAXException 60 {} 61 62 public void startEntity (String name) 63 throws SAXException 64 {} 65 66 public void endEntity (String name) 67 throws SAXException 68 {} 69 70 public void comment (char ch [], int start, int length) 71 throws SAXException 72 { } 73 74 75 // SAX2 ext-1.0 DeclHandler 76 77 public void attributeDecl (String eName, String aName, 78 String type, String mode, String value) 79 throws SAXException 80 {} 81 82 public void elementDecl (String name, String model) 83 throws SAXException 84 {} 85 86 public void externalEntityDecl (String name, 87 String publicId, String systemId) 88 throws SAXException 89 {} 90 91 public void internalEntityDecl (String name, String value) 92 throws SAXException 93 {} 94 95 // SAX2 ext-1.1 EntityResolver2 96 97 /** 98 * Tells the parser that if no external subset has been declared 99 * in the document text, none should be used. 100 * 101 * @param name Identifies the document root element. This name comes 102 * from a DOCTYPE declaration (where available) or from the actual 103 * root element. The parameter is ignored. 104 * @param baseURI The document's base URI, serving as an additional 105 * hint for selecting the external subset. This is always an absolute 106 * URI, unless it is null because the XMLReader was given an InputSource 107 * without one. The parameter is ignored. 108 * 109 * @return null (always). 110 * 111 * @exception SAXException Any SAX exception, possibly wrapping 112 * another exception. 113 * @exception IOException Probably indicating a failure to create 114 * a new InputStream or Reader, or an illegal URL. 115 */ 116 public InputSource getExternalSubset (String name, String baseURI) 117 throws SAXException, IOException 118 { return null; } 119 120 /** 121 * Tells the parser to resolve the systemId against the baseURI 122 * and read the entity text from that resulting absolute URI. 123 * Note that because the older 124 * {@link DefaultHandler#resolveEntity DefaultHandler.resolveEntity()}, 125 * method is overridden to call this one, this method may sometimes 126 * be invoked with null <em>name</em> and <em>baseURI</em>, and 127 * with the <em>systemId</em> already absolutized. 128 * 129 * @param name Identifies the external entity being resolved. 130 * Either "[dtd]" for the external subset, or a name starting 131 * with "%" to indicate a parameter entity, or else the name of 132 * a general entity. This is never null when invoked by a SAX2 133 * parser. 134 * @param publicId The public identifier of the external entity being 135 * referenced (normalized as required by the XML specification), or 136 * null if none was supplied. 137 * @param baseURI The URI with respect to which relative systemIDs 138 * are interpreted. This is always an absolute URI, unless it is 139 * null (likely because the XMLReader was given an InputSource without 140 * one). This URI is defined by the XML specification to be the one 141 * associated with the "<" starting the relevant declaration. 142 * @param systemId The system identifier of the external entity 143 * being referenced; either a relative or absolute URI. 144 * This is never null when invoked by a SAX2 parser; only declared 145 * entities, and any external subset, are resolved by such parsers. 146 * 147 * @return An InputSource object describing the new input source. 148 * 149 * @exception SAXException Any SAX exception, possibly wrapping 150 * another exception. 151 * @exception IOException Probably indicating a failure to create 152 * a new InputStream or Reader, or an illegal URL. 153 */ 154 public InputSource resolveEntity (String name, String publicId, 155 String baseURI, String systemId) 156 throws SAXException, IOException 157 { return null; } 158 159 // SAX1 EntityResolver 160 161 /** 162 * Invokes 163 * {@link EntityResolver2#resolveEntity EntityResolver2.resolveEntity()} 164 * with null entity name and base URI. 165 * You only need to override that method to use this class. 166 * 167 * @param publicId The public identifier of the external entity being 168 * referenced (normalized as required by the XML specification), or 169 * null if none was supplied. 170 * @param systemId The system identifier of the external entity 171 * being referenced; either a relative or absolute URI. 172 * This is never null when invoked by a SAX2 parser; only declared 173 * entities, and any external subset, are resolved by such parsers. 174 * 175 * @return An InputSource object describing the new input source. 176 * 177 * @exception SAXException Any SAX exception, possibly wrapping 178 * another exception. 179 * @exception IOException Probably indicating a failure to create 180 * a new InputStream or Reader, or an illegal URL. 181 */ 182 public InputSource resolveEntity (String publicId, String systemId) 183 throws SAXException, IOException 184 { return resolveEntity (null, publicId, null, systemId); } 185 } 186
