DefaultHandler

DefaultHandler

org.xml.sax.helpers

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Java 1.4

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.DefaultHandler

 public 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  } 

Subclasses

org.xml.sax.ext.DefaultHandler2

Passed To

javax.xml.parsers.SAXParser.parse( )