gnu.xml.aelfred2
Class XmlReader

java.lang.Object
  extended bygnu.xml.aelfred2.XmlReader
All Implemented Interfaces:
XMLReader

public final class XmlReader
extends Object
implements XMLReader

This SAX2 parser optionally layers a validator over the Ælfred2 SAX2 parser. While this will not evaluate every XML validity constraint, it does support all the validity constraints that are of any real utility outside the strict SGML-compatible world. See the documentation for the SAXDriver class for information about the SAX2 features and properties that are supported, and documentation for the ValidationConsumer for information about what validity constraints may not be supported. (Ælfred2 tests some of those, even in non-validating mode, to achieve better conformance.)

Note that due to its internal construction, you can't change most handlers until parse() returns. This diverges slightly from SAX, which expects later binding to be supported. Early binding involves less runtime overhead, which is an issue for event pipelines as used inside this parser. Rather than relying on the parser to handle late binding to your own handlers, do it yourself.

Version:
$Date: 2001/11/09 22:55:43 $
Author:
David Brownell
See Also:
SAXDriver, ValidationConsumer

Constructor Summary
XmlReader()
          Constructs a SAX Parser.
XmlReader(boolean invalidIsFatal)
          Constructs a SAX Parser, optionally treating validity errors as if they were fatal errors.
 
Method Summary
 ContentHandler getContentHandler()
          SAX2: Returns the object used to report the logical content of an XML document.
 DTDHandler getDTDHandler()
          SAX2: Returns the object used to process declarations related to notations and unparsed entities.
 EntityResolver getEntityResolver()
          SAX2: Returns the object used when resolving external entities during parsing (both general and parameter entities).
 ErrorHandler getErrorHandler()
          SAX2: Returns the object used to receive callbacks for XML errors of all levels (fatal, nonfatal, warning); this is never null;
 boolean getFeature(String featureId)
          SAX2: Tells whether this parser supports the specified feature.
 Object getProperty(String propertyId)
          SAX2: Returns the specified property.
 void parse(InputSource source)
          SAX1: Underlying API to parse an XML document, used directly when no URI is available.
 void parse(String systemId)
          SAX1: Preferred API to parse an XML document, using a system identifier (URI).
 void setContentHandler(ContentHandler handler)
          SAX2: Assigns the object used to report the logical content of an XML document.
 void setDTDHandler(DTDHandler handler)
          SAX1 Assigns DTD handler
 void setEntityResolver(EntityResolver handler)
          SAX1 Assigns parser's entity resolver
 void setErrorHandler(ErrorHandler handler)
          SAX1 Assigns error handler
 void setFeature(String featureId, boolean state)
          SAX2: Sets the state of features supported in this parser.
 void setLocale(Locale locale)
          SAX1: Sets the locale used for diagnostics; currently, only locales using the English language are supported.
 void setProperty(String propertyId, Object value)
          SAX2: Assigns the specified property.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

XmlReader

public XmlReader()
Constructs a SAX Parser.


XmlReader

public XmlReader(boolean invalidIsFatal)
Constructs a SAX Parser, optionally treating validity errors as if they were fatal errors.

Method Detail

getContentHandler

public ContentHandler getContentHandler()
SAX2: Returns the object used to report the logical content of an XML document.

Specified by:
getContentHandler in interface XMLReader
Returns:
The current content handler, or null if none has been registered.
See Also:
XMLReader.setContentHandler(org.xml.sax.ContentHandler)

setContentHandler

public void setContentHandler(ContentHandler handler)
SAX2: Assigns the object used to report the logical content of an XML document.

Specified by:
setContentHandler in interface XMLReader
Parameters:
handler - The content handler.
Throws:
IllegalStateException - if called mid-parse
See Also:
XMLReader.getContentHandler()

getDTDHandler

public DTDHandler getDTDHandler()
SAX2: Returns the object used to process declarations related to notations and unparsed entities.

Specified by:
getDTDHandler in interface XMLReader
Returns:
The current DTD handler, or null if none has been registered.
See Also:
XMLReader.setDTDHandler(org.xml.sax.DTDHandler)

setDTDHandler

public void setDTDHandler(DTDHandler handler)
SAX1 Assigns DTD handler

Specified by:
setDTDHandler in interface XMLReader
Parameters:
handler - The DTD handler.
Throws:
IllegalStateException - if called mid-parse
See Also:
XMLReader.getDTDHandler()

getEntityResolver

public EntityResolver getEntityResolver()
SAX2: Returns the object used when resolving external entities during parsing (both general and parameter entities).

Specified by:
getEntityResolver in interface XMLReader
Returns:
The current entity resolver, or null if none has been registered.
See Also:
XMLReader.setEntityResolver(org.xml.sax.EntityResolver)

setEntityResolver

public void setEntityResolver(EntityResolver handler)
SAX1 Assigns parser's entity resolver

Specified by:
setEntityResolver in interface XMLReader
Parameters:
handler - The entity resolver.
See Also:
XMLReader.getEntityResolver()

getErrorHandler

public ErrorHandler getErrorHandler()
SAX2: Returns the object used to receive callbacks for XML errors of all levels (fatal, nonfatal, warning); this is never null;

Specified by:
getErrorHandler in interface XMLReader
Returns:
The current error handler, or null if none has been registered.
See Also:
XMLReader.setErrorHandler(org.xml.sax.ErrorHandler)

setErrorHandler

public void setErrorHandler(ErrorHandler handler)
SAX1 Assigns error handler

Specified by:
setErrorHandler in interface XMLReader
Parameters:
handler - The error handler.
Throws:
IllegalStateException - if called mid-parse
See Also:
XMLReader.getErrorHandler()

setProperty

public void setProperty(String propertyId,
                        Object value)
                 throws SAXNotRecognizedException,
                        SAXNotSupportedException
SAX2: Assigns the specified property.

Specified by:
setProperty in interface XMLReader
Parameters:
propertyId - The property name, which is a fully-qualified URI.
value - The requested value for the property.
Throws:
IllegalStateException - if called mid-parse
SAXNotSupportedException - When the XMLReader recognizes the property name but cannot set the requested value.
SAXNotRecognizedException - If the property value can't be assigned or retrieved.

getProperty

public Object getProperty(String propertyId)
                   throws SAXNotRecognizedException
SAX2: Returns the specified property.

Specified by:
getProperty in interface XMLReader
Parameters:
propertyId - The property name, which is a fully-qualified URI.
Returns:
The current value of the property.
Throws:
SAXNotRecognizedException - If the property value can't be assigned or retrieved.
See Also:
XMLReader.setProperty(java.lang.String, java.lang.Object)

setFeature

public void setFeature(String featureId,
                       boolean state)
                throws SAXNotRecognizedException,
                       SAXNotSupportedException
SAX2: Sets the state of features supported in this parser. Note that this parser requires reporting of namespace prefixes when validating.

Specified by:
setFeature in interface XMLReader
Parameters:
featureId - The feature name, which is a fully-qualified URI.
state - The requested value of the feature (true or false).
Throws:
SAXNotRecognizedException - If the feature value can't be assigned or retrieved.
SAXNotSupportedException - When the XMLReader recognizes the feature name but cannot set the requested value.
See Also:
XMLReader.getFeature(java.lang.String)

getFeature

public boolean getFeature(String featureId)
                   throws SAXNotRecognizedException,
                          SAXNotSupportedException
SAX2: Tells whether this parser supports the specified feature. At this time, this directly parallels the underlying SAXDriver, except that validation is optionally supported.

Specified by:
getFeature in interface XMLReader
Parameters:
featureId - The feature name, which is a fully-qualified URI.
Returns:
The current value of the feature (true or false).
Throws:
SAXNotSupportedException - When the XMLReader recognizes the feature name but cannot determine its value at this time.
SAXNotRecognizedException - If the feature value can't be assigned or retrieved.
See Also:
SAXDriver

setLocale

public void setLocale(Locale locale)
               throws SAXException
SAX1: Sets the locale used for diagnostics; currently, only locales using the English language are supported.

Parameters:
locale - The locale for which diagnostics will be generated
Throws:
SAXException

parse

public void parse(String systemId)
           throws SAXException,
                  IOException
SAX1: Preferred API to parse an XML document, using a system identifier (URI).

Specified by:
parse in interface XMLReader
Parameters:
systemId - The system identifier (URI).
Throws:
SAXException - Any SAX exception, possibly wrapping another exception.
IOException - An IO exception from the parser, possibly from a byte stream or character stream supplied by the application.
See Also:
XMLReader.parse(org.xml.sax.InputSource)

parse

public void parse(InputSource source)
           throws SAXException,
                  IOException
SAX1: Underlying API to parse an XML document, used directly when no URI is available. When this is invoked, and the parser is set to validate, some features will be automatically reset to appropriate values: for reporting namespace prefixes, and incorporating external entities.

Specified by:
parse in interface XMLReader
Parameters:
source - The XML input source.
Throws:
IllegalStateException - if called mid-parse
SAXException - The handlers may throw any SAXException, and the parser normally throws SAXParseException objects.
IOException - IOExceptions are normally through through the parser if there are problems reading the source document.
See Also:
InputSource, XMLReader.parse(java.lang.String), XMLReader.setEntityResolver(org.xml.sax.EntityResolver), XMLReader.setDTDHandler(org.xml.sax.DTDHandler), XMLReader.setContentHandler(org.xml.sax.ContentHandler), XMLReader.setErrorHandler(org.xml.sax.ErrorHandler)


Source code is under GPL (with library exception) in the JAXP project at http://www.gnu.org/software/classpathx/jaxp
This documentation was derived from that source code on 2004-06-11.