de.frame4j.xml

Class SAXHandler

java.lang.Object

de.frame4j.xml.ParseErrorHandler

de.frame4j.xml.SAXHandler

All Implemented Interfaces:

ContentHandler, ErrorHandler

Direct Known Subclasses:

GrafHelper.MBarFactory

@MinDoc(copyright="Copyright  2005, 2009  A. Weinert",
        author="Albrecht Weinert",
        version="V.33",
        lastModified="27.03.2021",
        usage="use as is or extend  for own (SAX) XML parsers",
        purpose="provide a comfortable (base for) XML parsers")
public class SAXHandler
extends ParseErrorHandler
implements ErrorHandler, ContentHandler

An event handler for SAX applications.

Extending ParseErrorHandler, objects of this class are error handlers for XML parsers. Additionally they implement a content handler for SAX parser, hence being able to act as the one (and only) common handler for SAX applications.

As the error handler behaviour most often can be utilised unchanged, the content handler part has at least partly be overridden in most cases, startElement(String, String, String, Attributes). For many application cases this as only change in an inheritor is sufficient.
Note that all other implementations of ContentHandler methods in this class do nothing.

The (inner) class GrafHelper.MBarFactory is one example of a class extending SAXHandler. By comparably simple overriding of just startDocument(), startElement() and endElement() it is a powerful factory for MenuBars or JMenuBars.


© Copyright 2005, 2009 Albrecht Weinert

Version:

33 (27.03.2021)

Author:

Albrecht Weinert

See Also:

de.frame4j

Field Summary

Fields inherited from class de.frame4j.xml.ParseErrorHandler

errorCount, fatalCount, log, name, reThrow, warningCount

Constructor Summary

Constructors

Constructor and Description
SAXHandler(CharSequence name, PrintWriter log, boolean reThrow) SAXHandler by name of the XML input and with report output.

Method Summary

Modifier and Type	Method and Description
void	characters(char[] ch, int start, int length) This implementation does nothing.
void	endDocument() This implementation does nothing.
void	endElement(String namespaceURI, String localName, String qName) This implementation does nothing.
void	endPrefixMapping(String prefix) This implementation does nothing.
Object	getProduct() Deliver the product of the (ready, successful) parsing.
void	ignorableWhitespace(char[] ch, int start, int length) This implementation does nothing.
void	processingInstruction(String target, String data) This implementation does nothing.
void	setDocumentLocator(Locator locator) This implementation does nothing.
void	skippedEntity(String name) This implementation does nothing.
void	startDocument() This implementation does nothing.
void	startElement(String namespaceURI, String localName, String qName, Attributes atts) Start of a XML elements.
void	startPrefixMapping(String prefix, String uri) This implementation does nothing.

Methods inherited from class de.frame4j.xml.ParseErrorHandler

appRep, error, fatalError, getName, init, report, reportErrors, toString, toStringBuilder, warning

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.xml.sax.ErrorHandler

error, fatalError, warning

Constructor Detail

SAXHandler

public SAXHandler(CharSequence name,
                  PrintWriter log,
                  boolean reThrow)

SAXHandler by name of the XML input and with report output.

A SAXHandler object will be made named according to the parameter ParseErrorHandler.name or "...".

As PrintStream ParseErrorHandler.log the parameter log is taken if not null and the (decorated) normal output (System.out) otherwise.

Parameters:

name - the handler's or the input's name (stripped from surrounding white space; null or empty is taken as "..."

log - destination for reports

reThrow - if true error exceptions are thrown (again) and not just reported

See Also:

ParseErrorHandler.init(CharSequence, boolean), ParseErrorHandler(CharSequence, PrintWriter, boolean)

Method Detail

getProduct

public Object getProduct()

Deliver the product of the (ready, successful) parsing.

May or must be overridden in extending (especially anonymous) classes if necessary.

This implementation returns null.

Returns:

null or object of factory's product type

startElement

public void startElement(String namespaceURI,
                         String localName,
                         String qName,
                         Attributes atts)
                  throws SAXException

Start of a XML elements.

This implementation lists name an all attributes of the visited element on ParseErrorHandler.log. This method and hence this class is a first useful test step for the intended SAX application.
For all other purposes this is the method that has to be overridden in an inheritor. (Chances are good that it is the only one, if not to complex state machines are sufficient.)

Specified by:

startElement in interface ContentHandler

Throws:

SAXException

See Also:

ContentHandler.startElement(java.lang.String, java.lang.String, java.lang.String, org.xml.sax.Attributes)

endDocument

public void endDocument()
                 throws SAXException

This implementation does nothing.

Specified by:

endDocument in interface ContentHandler

Throws:

SAXException

See Also:

ContentHandler.endDocument()

startDocument

public void startDocument()
                   throws SAXException

This implementation does nothing.

Specified by:

startDocument in interface ContentHandler

Throws:

SAXException

See Also:

ContentHandler.startDocument()

characters

public void characters(char[] ch,
                       int start,
                       int length)
                throws SAXException

This implementation does nothing.

Specified by:

characters in interface ContentHandler

Throws:

SAXException

See Also:

ContentHandler.characters(char[], int, int)

ignorableWhitespace

public void ignorableWhitespace(char[] ch,
                                int start,
                                int length)
                         throws SAXException

This implementation does nothing.

Specified by:

ignorableWhitespace in interface ContentHandler

Throws:

SAXException

See Also:

ContentHandler.ignorableWhitespace(char[], int, int)

endPrefixMapping

public void endPrefixMapping(String prefix)
                      throws SAXException

This implementation does nothing.

Specified by:

endPrefixMapping in interface ContentHandler

Throws:

SAXException

See Also:

ContentHandler.endPrefixMapping(java.lang.String)

skippedEntity

public void skippedEntity(String name)
                   throws SAXException

This implementation does nothing.

Specified by:

skippedEntity in interface ContentHandler

Throws:

SAXException

See Also:

ContentHandler.skippedEntity(java.lang.String)

setDocumentLocator

public void setDocumentLocator(Locator locator)

This implementation does nothing.

Specified by:

setDocumentLocator in interface ContentHandler

See Also:

ContentHandler.setDocumentLocator(org.xml.sax.Locator)

processingInstruction

public void processingInstruction(String target,
                                  String data)
                           throws SAXException

This implementation does nothing.

Specified by:

processingInstruction in interface ContentHandler

Throws:

SAXException

See Also:

ContentHandler.processingInstruction(String, java.lang.String)

startPrefixMapping

public void startPrefixMapping(String prefix,
                               String uri)
                        throws SAXException

This implementation does nothing.

Specified by:

startPrefixMapping in interface ContentHandler

Throws:

SAXException

See Also:

ContentHandler.startPrefixMapping(String, String)

endElement

public void endElement(String namespaceURI,
                       String localName,
                       String qName)
                throws SAXException

This implementation does nothing.

Specified by:

endElement in interface ContentHandler

Throws:

SAXException

See Also:

ContentHandler.endElement(String, String, String)