001    // DefaultHandler2.java - extended DefaultHandler
002    // http://www.saxproject.org
003    // Public Domain: no warranty.
004    // $Id: DefaultHandler2.java,v 1.1 2004/12/23 22:38:42 mark Exp $
005    
006    package org.xml.sax.ext;
007    
008    import java.io.IOException;
009    import org.xml.sax.InputSource;
010    import org.xml.sax.SAXException;
011    import org.xml.sax.helpers.DefaultHandler;
012    
013    
014    /**
015     * This class extends the SAX2 base handler class to support the
016     * SAX2 {@link LexicalHandler}, {@link DeclHandler}, and
017     * {@link EntityResolver2} extensions.  Except for overriding the
018     * original SAX1 {@link DefaultHandler#resolveEntity resolveEntity()}
019     * method the added handler methods just return.  Subclassers may
020     * override everything on a method-by-method basis.
021     *
022     * <blockquote>
023     * <em>This module, both source code and documentation, is in the
024     * Public Domain, and comes with <strong>NO WARRANTY</strong>.</em>
025     * </blockquote>
026     *
027     * <p> <em>Note:</em> this class might yet learn that the
028     * <em>ContentHandler.setDocumentLocator()</em> call might be passed a
029     * {@link Locator2} object, and that the
030     * <em>ContentHandler.startElement()</em> call might be passed a
031     * {@link Attributes2} object.
032     *
033     * @since SAX 2.0 (extensions 1.1 alpha)
034     * @author David Brownell
035     * @version TBS
036     */
037    public class DefaultHandler2 extends DefaultHandler
038        implements LexicalHandler, DeclHandler, EntityResolver2
039    {
040        /** Constructs a handler which ignores all parsing events. */
041        public DefaultHandler2 () { }
042    
043    
044        // SAX2 ext-1.0 LexicalHandler
045    
046        public void startCDATA ()
047        throws SAXException
048            {}
049    
050        public void endCDATA ()
051        throws SAXException
052            {}
053    
054        public void startDTD (String name, String publicId, String systemId)
055        throws SAXException
056            {}
057    
058        public void endDTD ()
059        throws SAXException
060            {}
061    
062        public void startEntity (String name)
063        throws SAXException
064            {}
065    
066        public void endEntity (String name)
067        throws SAXException
068            {}
069    
070        public void comment (char ch [], int start, int length)
071        throws SAXException
072            { }
073    
074    
075        // SAX2 ext-1.0 DeclHandler
076    
077        public void attributeDecl (String eName, String aName,
078                String type, String mode, String value)
079        throws SAXException
080            {}
081    
082        public void elementDecl (String name, String model)
083        throws SAXException
084            {}
085    
086        public void externalEntityDecl (String name,
087            String publicId, String systemId)
088        throws SAXException
089            {}
090    
091        public void internalEntityDecl (String name, String value)
092        throws SAXException
093            {}
094    
095        // SAX2 ext-1.1 EntityResolver2
096    
097        /**
098         * Tells the parser that if no external subset has been declared
099         * in the document text, none should be used.
100         */
101        public InputSource getExternalSubset (String name, String baseURI)
102        throws SAXException, IOException
103            { return null; }
104    
105        /**
106         * Tells the parser to resolve the systemId against the baseURI
107         * and read the entity text from that resulting absolute URI.
108         * Note that because the older
109         * {@link DefaultHandler#resolveEntity DefaultHandler.resolveEntity()},
110         * method is overridden to call this one, this method may sometimes
111         * be invoked with null <em>name</em> and <em>baseURI</em>, and
112         * with the <em>systemId</em> already absolutized.
113         */
114        public InputSource resolveEntity (String name, String publicId,
115                String baseURI, String systemId)
116        throws SAXException, IOException
117            { return null; }
118    
119        // SAX1 EntityResolver
120    
121        /**
122         * Invokes
123         * {@link EntityResolver2#resolveEntity EntityResolver2.resolveEntity()}
124         * with null entity name and base URI.
125         * You only need to override that method to use this class.
126         */
127        public InputSource resolveEntity (String publicId, String systemId)
128        throws SAXException, IOException
129            { return resolveEntity (null, publicId, null, systemId); }
130    }