org.apache.cayenne.util
Class AbstractHandler

java.lang.Object
  org.xml.sax.helpers.DefaultHandler
      org.apache.cayenne.util.AbstractHandler

All Implemented Interfaces:

org.xml.sax.ContentHandler, org.xml.sax.DTDHandler, org.xml.sax.EntityResolver, org.xml.sax.ErrorHandler

Deprecated. since 1.2 - this is moved to a non-public class in conf package.

public class AbstractHandler
extends org.xml.sax.helpers.DefaultHandler

The common superclass for all SAX event handlers used to parse the configuration file. Each method just throws an exception, so subclasses should override what they can handle. Each type of XML element (map, node, etc.) has a specific subclass. In the constructor, this class takes over the handling of SAX events from the parent handler and returns control back to the parent in the endElement method.

The idea to use nested handlers for XML document parsing (and code to implement it) were taken from org.apache.tools.ant.ProjectHelper from Jakarta-Ant project (Copyright: Apache Software Foundation). This may not be the best way to build objects from XML, but it is rather consistent. For each nested element in the XML tree a dedicated handler is created (subclass of this AbstractHandler). Once the element is parsed, control is handled back to the parent handler.

Author:

Andrei Adamchik

Field Summary

protected org.xml.sax.ContentHandler	parentHandler Deprecated. Previous handler for the document.
protected org.xml.sax.XMLReader	parser Deprecated. Current parser.

Constructor Summary

AbstractHandler(org.xml.sax.XMLReader parser, org.xml.sax.ContentHandler parentHandler)
Deprecated. Creates a handler and sets the parser to use it for the current element.

Method Summary

void	characters(char[] buf, int start, int count) Deprecated. Handles text within an element.
void	endElement(java.lang.String namespaceURI, java.lang.String localName, java.lang.String qName) Deprecated. Handles the end of an element.
protected void	finished() Deprecated. Called when this element and all elements nested into it have been handled.
org.xml.sax.XMLReader	getParser() Deprecated. Returns currently used XMLReader.
void	startElement(java.lang.String namespaceURI, java.lang.String localName, java.lang.String qName, org.xml.sax.Attributes atts) Deprecated. Handles the start of an element.

Methods inherited from class org.xml.sax.helpers.DefaultHandler

endDocument, endPrefixMapping, error, fatalError, ignorableWhitespace, notationDecl, processingInstruction, resolveEntity, setDocumentLocator, skippedEntity, startDocument, startPrefixMapping, unparsedEntityDecl, warning

Methods inherited from class java.lang.Object

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

Field Detail

parser

protected org.xml.sax.XMLReader parser

Deprecated.

Current parser.

parentHandler

protected org.xml.sax.ContentHandler parentHandler

Deprecated.

Previous handler for the document. When the next element is finished, control returns to this handler.

Constructor Detail

AbstractHandler

public AbstractHandler(org.xml.sax.XMLReader parser,
                       org.xml.sax.ContentHandler parentHandler)

Deprecated.

Creates a handler and sets the parser to use it for the current element.

Parameters:

parser - Currently used XML parser. Must not be null.

parentHandler - The handler which should be restored to the parser at the end of the element. Must not be null.

Method Detail

getParser

public org.xml.sax.XMLReader getParser()

Deprecated.

Returns currently used XMLReader.

startElement

public void startElement(java.lang.String namespaceURI,
                         java.lang.String localName,
                         java.lang.String qName,
                         org.xml.sax.Attributes atts)
                  throws org.xml.sax.SAXException

Deprecated.

Handles the start of an element. This base implementation just throws an exception.

Specified by:

startElement in interface org.xml.sax.ContentHandler

Overrides:

startElement in class org.xml.sax.helpers.DefaultHandler

Throws:

org.xml.sax.SAXException - if this method is not overridden, or in case of error in an overridden version

characters

public void characters(char[] buf,
                       int start,
                       int count)
                throws org.xml.sax.SAXException

Deprecated.

Handles text within an element. This base implementation just throws an exception.

Specified by:

characters in interface org.xml.sax.ContentHandler

Overrides:

characters in class org.xml.sax.helpers.DefaultHandler

Parameters:

buf - A character array of the text within the element. Will not be null.

start - The start element in the array.

count - The number of characters to read from the array.

Throws:

org.xml.sax.SAXException - if this method is not overridden, or in case of error in an overridden version

finished

protected void finished()

Deprecated.

Called when this element and all elements nested into it have been handled.

endElement

public void endElement(java.lang.String namespaceURI,
                       java.lang.String localName,
                       java.lang.String qName)
                throws org.xml.sax.SAXException

Deprecated.

Handles the end of an element. Any required clean-up is performed by the finished() method and then the original handler is restored to the parser.

Specified by:

endElement in interface org.xml.sax.ContentHandler

Overrides:

endElement in class org.xml.sax.helpers.DefaultHandler

Throws:

org.xml.sax.SAXException

See Also:

finished()