This helper class implements the four commonly-used SAX handler interfaces from the org.xml.sax package and defines stub implementations for all of their methods . It is usually easier to subclass DefaultHandler and override the desired methods than it is to implement all of the interfaces (and all of their methods) from scratch. DefaultHandler implements ContentHandler , ErrorHandler , EntityResolver and DTDHandler , so you can pass an instance of this class, (or of a subclass you define) to the setContentHandler( ) , setErrorHandler( ) , setEntityResolver( ) , and setDTDHandler( ) methods of an XMLReader . You can also pass an instance of a DefaultHandler subclass directly to one of the parse( ) methods of a javax.xml.parsers.SAXParser . The SAXParser will take care of calling the four relevant methods of its internal XMLReader . All but two of the methods of DefaultHandler have empty bodies and do nothing. The exceptions are resolveEntity( ) which simply returns null to tell the parser to resolve the entity itself, and fatalError( ) which throws the SAXParseException object that is passed to it. Figure 22-15. org.xml.sax.helpers.DefaultHandlerpublic class DefaultHandler implements org.xml.sax.ContentHandler, org.xml.sax.DTDHandler, org.xml.sax.EntityResolver, org.xml.sax.ErrorHandler { // Public Constructors public DefaultHandler ( ); // Methods Implementing ContentHandler public void characters (char[ ] ch , int start , int length ) throws org.xml.sax.SAXException; empty public void endDocument ( ) throws org.xml.sax.SAXException; empty public void endElement (String uri , String localName , String qName ) throws org.xml.sax.SAXException; empty public void endPrefixMapping (String prefix ) throws org.xml.sax.SAXException; empty public void ignorableWhitespace (char[ ] ch , int start , int length ) throws org.xml.sax.SAXException; empty public void processingInstruction (String target , String data ) throws org.xml.sax.SAXException; empty public void setDocumentLocator (org.xml.sax.Locator locator ); empty public void skippedEntity (String name ) throws org.xml.sax.SAXException; empty public void startDocument ( ) throws org.xml.sax.SAXException; empty public void startElement (String uri , String localName , String qName , org.xml.sax.Attributes attributes ) throws org.xml.sax.SAXException; empty public void startPrefixMapping (String prefix , String uri ) throws org.xml.sax.SAXException; empty // Methods Implementing DTDHandler public void notationDecl (String name , String publicId , String systemId ) throws org.xml.sax.SAXException; empty public void unparsedEntityDecl (String name , String publicId , String systemId , String notationName ) throws org.xml.sax.SAXException; empty // Methods Implementing EntityResolver public org.xml.sax.InputSource resolveEntity (String publicId , String systemId ) throws java.io.IOException, org.xml.sax.SAXException; constant // Methods Implementing ErrorHandler public void error (org.xml.sax.SAXParseException e ) throws org.xml.sax.SAXException; empty public void fatalError (org.xml.sax.SAXParseException e ) throws org.xml.sax.SAXException; public void warning (org.xml.sax.SAXParseException e ) throws org.xml.sax.SAXException; empty } Subclassesorg.xml.sax.ext.DefaultHandler2 Passed Tojavax.xml.parsers.SAXParser.parse( ) |