org.apache.xml.resolver.readers

Class SAXCatalogReader

Implemented Interfaces:
CatalogReader, ContentHandler, DocumentHandler
Known Direct Subclasses:
OASISXMLCatalogReader, XCatalogReader

public class SAXCatalogReader
extends Object
implements CatalogReader, ContentHandler, DocumentHandler

A SAX-based CatalogReader.

This class is used to read XML Catalogs using the SAX. This reader has an advantage over the DOM-based reader in that it functions on the stream of SAX events. It has the disadvantage that it cannot look around in the tree.

Since the choice of CatalogReaders (in the InputStream case) can only be made on the basis of MIME type, the following problem occurs: only one CatalogReader can exist for all XML mime types. In order to get around this problem, the SAXCatalogReader relies on a set of external CatalogParsers to actually build the catalog.

The selection of CatalogParsers is made on the basis of the QName of the root element of the document.

Version:
1.0
Author:
Norman Walsh Norman.Walsh@Sun.COM
See Also:
Catalog, CatalogReader, SAXCatalogReader, TextCatalogReader, DOMCatalogParser

Field Summary

protected Debug
debug
The debug class to use for this reader.
protected Hashtable
namespaceMap
Mapping table from QNames to CatalogParser classes.
protected String
parserClass
The SAX Parser Class
protected SAXParserFactory
parserFactory
The SAX Parser Factory

Constructor Summary

SAXCatalogReader()
The constructor
SAXCatalogReader(SAXParserFactory parserFactory)
The constructor
SAXCatalogReader(String parserClass)
The constructor

Method Summary

void
characters(ch[] , int start, int length)
The SAX characters method.
void
endDocument()
The SAX endDocument method.
void
endElement(String name)
The SAX endElement method.
void
endElement(String namespaceURI, String localName, String qName)
The SAX2 endElement method.
void
endPrefixMapping(String prefix)
The SAX endPrefixMapping method.
String
getCatalogParser(String namespaceURI, String rootElement)
Get the SAXCatalogParser class for the given namespace/root element type.
String
getParserClass()
Get the parser class currently in use.
SAXParserFactory
getParserFactory()
Get the parser factory currently in use.
void
ignorableWhitespace(ch[] , int start, int length)
The SAX ignorableWhitespace method.
void
processingInstruction(String target, String data)
The SAX processingInstruction method.
void
readCatalog(Catalog catalog, InputStream is)
Parse an XML Catalog stream.
void
readCatalog(Catalog catalog, String fileUrl)
Parse an XML Catalog file.
void
setCatalogParser(String namespaceURI, String rootElement, String parserClass)
Set the SAXCatalogParser class for the given namespace/root element type.
void
setDocumentLocator(Locator locator)
The SAX setDocumentLocator method.
void
setParserClass(String parserClass)
Set the XML SAX Parser Class
void
setParserFactory(SAXParserFactory parserFactory)
Set the XML SAX Parser Factory.
void
skippedEntity(String name)
The SAX skippedentity method.
void
startDocument()
The SAX startDocument method.
void
startElement(String name, AttributeList atts)
The SAX startElement method.
void
startElement(String namespaceURI, String localName, String qName, Attributes atts)
The SAX2 startElement method.
void
startPrefixMapping(String prefix, String uri)
The SAX startPrefixMapping method.

Field Details

debug

protected Debug debug
The debug class to use for this reader. This is a bit of a hack. Anyway, whenever we read for a catalog, we extract the debug object from the catalog's manager so that we can use it to print messages. In production, we don't really expect any messages so it doesn't really matter. But it's still a bit of a hack.

namespaceMap

protected Hashtable namespaceMap
Mapping table from QNames to CatalogParser classes.

Each key in this hash table has the form "elementname" or "{namespaceuri}elementname". The former is used if the namespace URI is null.


parserClass

protected String parserClass
The SAX Parser Class

parserFactory

protected SAXParserFactory parserFactory
The SAX Parser Factory

Constructor Details

SAXCatalogReader

public SAXCatalogReader()
The constructor

SAXCatalogReader

public SAXCatalogReader(SAXParserFactory parserFactory)
The constructor

SAXCatalogReader

public SAXCatalogReader(String parserClass)
The constructor

Method Details

characters

public void characters(ch[] ,
                       int start,
                       int length)
            throws SAXException
The SAX characters method. Does nothing.

endDocument

public void endDocument()
            throws SAXException
The SAX endDocument method. Does nothing.

endElement

public void endElement(String name)
            throws SAXException
The SAX endElement method. Does nothing.

endElement

public void endElement(String namespaceURI,
                       String localName,
                       String qName)
            throws SAXException
The SAX2 endElement method. Does nothing.

endPrefixMapping

public void endPrefixMapping(String prefix)
            throws SAXException
The SAX endPrefixMapping method. Does nothing.

getCatalogParser

public String getCatalogParser(String namespaceURI,
                               String rootElement)
Get the SAXCatalogParser class for the given namespace/root element type.

getParserClass

public String getParserClass()
Get the parser class currently in use.

getParserFactory

public SAXParserFactory getParserFactory()
Get the parser factory currently in use.

ignorableWhitespace

public void ignorableWhitespace(ch[] ,
                                int start,
                                int length)
            throws SAXException
The SAX ignorableWhitespace method. Does nothing.

processingInstruction

public void processingInstruction(String target,
                                  String data)
            throws SAXException
The SAX processingInstruction method. Does nothing.

readCatalog

public void readCatalog(Catalog catalog,
                        InputStream is)
            throws IOException,
                   CatalogException
Parse an XML Catalog stream.
Specified by:
readCatalog in interface CatalogReader
Parameters:
catalog - The catalog to which this catalog file belongs
is - The input stream from which the catalog will be read
Throws:
CatalogException - A Catalog exception

readCatalog

public void readCatalog(Catalog catalog,
                        String fileUrl)
            throws MalformedURLException,
                   IOException,
                   CatalogException
Parse an XML Catalog file.
Specified by:
readCatalog in interface CatalogReader
Parameters:
catalog - The catalog to which this catalog file belongs
fileUrl - The URL or filename of the catalog file to process

setCatalogParser

public void setCatalogParser(String namespaceURI,
                             String rootElement,
                             String parserClass)
Set the SAXCatalogParser class for the given namespace/root element type.

setDocumentLocator

public void setDocumentLocator(Locator locator)
The SAX setDocumentLocator method. Does nothing.

setParserClass

public void setParserClass(String parserClass)
Set the XML SAX Parser Class

setParserFactory

public void setParserFactory(SAXParserFactory parserFactory)
Set the XML SAX Parser Factory.

skippedEntity

public void skippedEntity(String name)
            throws SAXException
The SAX skippedentity method. Does nothing.

startDocument

public void startDocument()
            throws SAXException
The SAX startDocument method. Does nothing.

startElement

public void startElement(String name,
                         AttributeList atts)
            throws SAXException
The SAX startElement method.

The catalog parser is selected based on the namespace of the first element encountered in the catalog.


startElement

public void startElement(String namespaceURI,
                         String localName,
                         String qName,
                         Attributes atts)
            throws SAXException
The SAX2 startElement method.

The catalog parser is selected based on the namespace of the first element encountered in the catalog.


startPrefixMapping

public void startPrefixMapping(String prefix,
                               String uri)
            throws SAXException
The SAX startPrefixMapping method. Does nothing.

Copyright B) 2001-2003 Apache Software Foundation. All Rights Reserved.