org.xml.sax.helpers

Class DefaultHandler

public class DefaultHandler extends Object implements EntityResolver, DTDHandler, ContentHandler, ErrorHandler

Default base class for SAX2 event handlers.
This module, both source code and documentation, is in the Public Domain, and comes with NO WARRANTY. See http://www.saxproject.org for further information.

This class is available as a convenience base class for SAX2 applications: it provides default implementations for all of the callbacks in the four core SAX2 handler classes:

Application writers can extend this class when they need to implement only part of an interface; parser writers can instantiate this class to provide default handlers when the application has not supplied its own.

This class replaces the deprecated SAX1 {@link org.xml.sax.HandlerBase HandlerBase} class.

Since: SAX 2.0

Version: 2.0.1 (sax2r2)

Author: David Megginson,

See Also: EntityResolver DTDHandler ContentHandler ErrorHandler

Method Summary
voidcharacters(char[] ch, int start, int length)
Receive notification of character data inside an element.
voidendDocument()
Receive notification of the end of the document.
voidendElement(String uri, String localName, String qName)
Receive notification of the end of an element.
voidendPrefixMapping(String prefix)
Receive notification of the end of a Namespace mapping.
voiderror(SAXParseException e)
Receive notification of a recoverable parser error.
voidfatalError(SAXParseException e)
Report a fatal XML parsing error.
voidignorableWhitespace(char[] ch, int start, int length)
Receive notification of ignorable whitespace in element content.
voidnotationDecl(String name, String publicId, String systemId)
Receive notification of a notation declaration.
voidprocessingInstruction(String target, String data)
Receive notification of a processing instruction.
InputSourceresolveEntity(String publicId, String systemId)
Resolve an external entity.
voidsetDocumentLocator(Locator locator)
Receive a Locator object for document events.
voidskippedEntity(String name)
Receive notification of a skipped entity.
voidstartDocument()
Receive notification of the beginning of the document.
voidstartElement(String uri, String localName, String qName, Attributes attributes)
Receive notification of the start of an element.
voidstartPrefixMapping(String prefix, String uri)
Receive notification of the start of a Namespace mapping.
voidunparsedEntityDecl(String name, String publicId, String systemId, String notationName)
Receive notification of an unparsed entity declaration.
voidwarning(SAXParseException e)
Receive notification of a parser warning.

Method Detail

characters

public void characters(char[] ch, int start, int length)
Receive notification of character data inside an element.

By default, do nothing. Application writers may override this method to take specific actions for each chunk of character data (such as adding the data to a node or buffer, or printing it to a file).

Parameters: ch The characters. start The start position in the character array. length The number of characters to use from the character array.

Throws: org.xml.sax.SAXException Any SAX exception, possibly wrapping another exception.

See Also: ContentHandler

endDocument

public void endDocument()
Receive notification of the end of the document.

By default, do nothing. Application writers may override this method in a subclass to take specific actions at the end of a document (such as finalising a tree or closing an output file).

Throws: org.xml.sax.SAXException Any SAX exception, possibly wrapping another exception.

See Also: ContentHandler

endElement

public void endElement(String uri, String localName, String qName)
Receive notification of the end of an element.

By default, do nothing. Application writers may override this method in a subclass to take specific actions at the end of each element (such as finalising a tree node or writing output to a file).

Parameters: uri The Namespace URI, or the empty string if the element has no Namespace URI or if Namespace processing is not being performed. localName The local name (without prefix), or the empty string if Namespace processing is not being performed. qName The qualified name (with prefix), or the empty string if qualified names are not available.

Throws: org.xml.sax.SAXException Any SAX exception, possibly wrapping another exception.

See Also: ContentHandler

endPrefixMapping

public void endPrefixMapping(String prefix)
Receive notification of the end of a Namespace mapping.

By default, do nothing. Application writers may override this method in a subclass to take specific actions at the end of each prefix mapping.

Parameters: prefix The Namespace prefix being declared.

Throws: org.xml.sax.SAXException Any SAX exception, possibly wrapping another exception.

See Also: ContentHandler

error

public void error(SAXParseException e)
Receive notification of a recoverable parser error.

The default implementation does nothing. Application writers may override this method in a subclass to take specific actions for each error, such as inserting the message in a log file or printing it to the console.

Parameters: e The warning information encoded as an exception.

Throws: org.xml.sax.SAXException Any SAX exception, possibly wrapping another exception.

See Also: ErrorHandler SAXParseException

fatalError

public void fatalError(SAXParseException e)
Report a fatal XML parsing error.

The default implementation throws a SAXParseException. Application writers may override this method in a subclass if they need to take specific actions for each fatal error (such as collecting all of the errors into a single report): in any case, the application must stop all regular processing when this method is invoked, since the document is no longer reliable, and the parser may no longer report parsing events.

Parameters: e The error information encoded as an exception.

Throws: org.xml.sax.SAXException Any SAX exception, possibly wrapping another exception.

See Also: ErrorHandler SAXParseException

ignorableWhitespace

public void ignorableWhitespace(char[] ch, int start, int length)
Receive notification of ignorable whitespace in element content.

By default, do nothing. Application writers may override this method to take specific actions for each chunk of ignorable whitespace (such as adding data to a node or buffer, or printing it to a file).

Parameters: ch The whitespace characters. start The start position in the character array. length The number of characters to use from the character array.

Throws: org.xml.sax.SAXException Any SAX exception, possibly wrapping another exception.

See Also: ContentHandler

notationDecl

public void notationDecl(String name, String publicId, String systemId)
Receive notification of a notation declaration.

By default, do nothing. Application writers may override this method in a subclass if they wish to keep track of the notations declared in a document.

Parameters: name The notation name. publicId The notation public identifier, or null if not available. systemId The notation system identifier.

Throws: org.xml.sax.SAXException Any SAX exception, possibly wrapping another exception.

See Also: DTDHandler

processingInstruction

public void processingInstruction(String target, String data)
Receive notification of a processing instruction.

By default, do nothing. Application writers may override this method in a subclass to take specific actions for each processing instruction, such as setting status variables or invoking other methods.

Parameters: target The processing instruction target. data The processing instruction data, or null if none is supplied.

Throws: org.xml.sax.SAXException Any SAX exception, possibly wrapping another exception.

See Also: ContentHandler

resolveEntity

public InputSource resolveEntity(String publicId, String systemId)
Resolve an external entity.

Always return null, so that the parser will use the system identifier provided in the XML document. This method implements the SAX default behaviour: application writers can override it in a subclass to do special translations such as catalog lookups or URI redirection.

Parameters: publicId The public identifer, or null if none is available. systemId The system identifier provided in the XML document.

Returns: The new input source, or null to require the default behaviour.

Throws: java.io.IOException If there is an error setting up the new input source. org.xml.sax.SAXException Any SAX exception, possibly wrapping another exception.

See Also: EntityResolver

setDocumentLocator

public void setDocumentLocator(Locator locator)
Receive a Locator object for document events.

By default, do nothing. Application writers may override this method in a subclass if they wish to store the locator for use with other document events.

Parameters: locator A locator for all SAX document events.

See Also: ContentHandler Locator

skippedEntity

public void skippedEntity(String name)
Receive notification of a skipped entity.

By default, do nothing. Application writers may override this method in a subclass to take specific actions for each processing instruction, such as setting status variables or invoking other methods.

Parameters: name The name of the skipped entity.

Throws: org.xml.sax.SAXException Any SAX exception, possibly wrapping another exception.

See Also: ContentHandler

startDocument

public void startDocument()
Receive notification of the beginning of the document.

By default, do nothing. Application writers may override this method in a subclass to take specific actions at the beginning of a document (such as allocating the root node of a tree or creating an output file).

Throws: org.xml.sax.SAXException Any SAX exception, possibly wrapping another exception.

See Also: ContentHandler

startElement

public void startElement(String uri, String localName, String qName, Attributes attributes)
Receive notification of the start of an element.

By default, do nothing. Application writers may override this method in a subclass to take specific actions at the start of each element (such as allocating a new tree node or writing output to a file).

Parameters: uri The Namespace URI, or the empty string if the element has no Namespace URI or if Namespace processing is not being performed. localName The local name (without prefix), or the empty string if Namespace processing is not being performed. qName The qualified name (with prefix), or the empty string if qualified names are not available. atts The attributes attached to the element. If there are no attributes, it shall be an empty Attributes object.

Throws: org.xml.sax.SAXException Any SAX exception, possibly wrapping another exception.

See Also: ContentHandler

startPrefixMapping

public void startPrefixMapping(String prefix, String uri)
Receive notification of the start of a Namespace mapping.

By default, do nothing. Application writers may override this method in a subclass to take specific actions at the start of each Namespace prefix scope (such as storing the prefix mapping).

Parameters: prefix The Namespace prefix being declared. uri The Namespace URI mapped to the prefix.

Throws: org.xml.sax.SAXException Any SAX exception, possibly wrapping another exception.

See Also: ContentHandler

unparsedEntityDecl

public void unparsedEntityDecl(String name, String publicId, String systemId, String notationName)
Receive notification of an unparsed entity declaration.

By default, do nothing. Application writers may override this method in a subclass to keep track of the unparsed entities declared in a document.

Parameters: name The entity name. publicId The entity public identifier, or null if not available. systemId The entity system identifier. notationName The name of the associated notation.

Throws: org.xml.sax.SAXException Any SAX exception, possibly wrapping another exception.

See Also: DTDHandler

warning

public void warning(SAXParseException e)
Receive notification of a parser warning.

The default implementation does nothing. Application writers may override this method in a subclass to take specific actions for each warning, such as inserting the message in a log file or printing it to the console.

Parameters: e The warning information encoded as an exception.

Throws: org.xml.sax.SAXException Any SAX exception, possibly wrapping another exception.

See Also: ErrorHandler SAXParseException