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 * Copyright (c) 2003, 2005, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
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 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
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 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package javax.xml.validation;

import org.w3c.dom.ls.LSResourceResolver;
import org.xml.sax.ContentHandler;
import org.xml.sax.ErrorHandler;
import org.xml.sax.SAXNotRecognizedException;
import org.xml.sax.SAXNotSupportedException;


Streaming validator that works on SAX stream.

 A ValidatorHandler object is not thread-safe and not reentrant. In other words, it is the application's responsibility to make sure that one ValidatorHandler object is not used from more than one thread at any given time. 
 ValidatorHandler checks if the SAX events follow the set of constraints described in the associated Schema, and additionally it may modify the SAX events (for example by adding default values, etc.) 
 ValidatorHandler extends from ContentHandler, but it refines the underlying ContentHandler in the following way: 
    
 
  1. startElement/endElement events must receive non-null String
     for uri, localName, and qname, even though SAX allows some of them to be null. Similarly, the user-specified ContentHandler will receive non-null Strings for all three parameters. 
  2. Applications must ensure that ValidatorHandler's ContentHandler.startPrefixMapping(String, String) and ContentHandler.endPrefixMapping(String) are invoked properly. Similarly, the user-specified ContentHandler will receive startPrefixMapping/endPrefixMapping events. If the ValidatorHandler introduces additional namespace bindings, the user-specified ContentHandler will receive additional startPrefixMapping/endPrefixMapping events. 
  3. Attributes for the ContentHandler.startElement(String, String, String, Attributes) method may or may not include xmlns* attributes. 


 A ValidatorHandler is automatically reset every time the startDocument method is invoked. 
Recognized Properties and Features


 This spec defines the following feature that must be recognized by all ValidatorHandler implementations. 
http://xml.org/sax/features/namespace-prefixes


 This feature controls how a ValidatorHandler introduces namespace bindings that were not present in the original SAX event stream. When this feature is set to true, it must make sure that the user's ContentHandler will see the corresponding xmlns* attribute in the Attributes object of the ContentHandler.startElement(String, String, String, Attributes) callback. Otherwise, xmlns* attributes must not be added to Attributes that's passed to the user-specified ContentHandler. 
 (Note that regardless of this switch, namespace bindings are always notified to applications through ContentHandler.startPrefixMapping(String, String) and ContentHandler.endPrefixMapping(String) methods of the ContentHandler specified by the user.) 

Note that this feature does NOT affect the way a ValidatorHandler receives SAX events. It merely changes the way it augments SAX events. 
This feature is set to false by default.


Author: Kohsuke Kawaguchi
Since:1.5
/**
 * Streaming validator that works on SAX stream.
 *
 * <p>
 * A {@link ValidatorHandler} object is not thread-safe and not reentrant.
 * In other words, it is the application's responsibility to make
 * sure that one {@link ValidatorHandler} object is not used from
 * more than one thread at any given time.
 *
 * <p>
 * {@link ValidatorHandler} checks if the SAX events follow
 * the set of constraints described in the associated {@link Schema},
 * and additionally it may modify the SAX events (for example
 * by adding default values, etc.)
 *
 * <p>
 * {@link ValidatorHandler} extends from {@link ContentHandler},
 * but it refines the underlying {@link ContentHandler} in
 * the following way:
 * <ol>
 *  <li>startElement/endElement events must receive non-null String
 *      for <code>uri</code>, <code>localName</code>, and <code>qname</code>,
 *      even though SAX allows some of them to be null.
 *      Similarly, the user-specified {@link ContentHandler} will receive non-null
 *      Strings for all three parameters.
 *
 *  <li>Applications must ensure that {@link ValidatorHandler}'s
 *      {@link ContentHandler#startPrefixMapping(String,String)} and
 *      {@link ContentHandler#endPrefixMapping(String)} are invoked
 *      properly. Similarly, the user-specified {@link ContentHandler}
 *      will receive startPrefixMapping/endPrefixMapping events.
 *      If the {@link ValidatorHandler} introduces additional namespace
 *      bindings, the user-specified {@link ContentHandler} will receive
 *      additional startPrefixMapping/endPrefixMapping events.
 *
 *  <li>{@link org.xml.sax.Attributes} for the
 *      {@link ContentHandler#startElement(String,String,String,Attributes)} method
 *      may or may not include xmlns* attributes.
 * </ol>
 *
 * <p>
 * A {@link ValidatorHandler} is automatically reset every time
 * the startDocument method is invoked.
 *
 * <h2>Recognized Properties and Features</h2>
 * <p>
 * This spec defines the following feature that must be recognized
 * by all {@link ValidatorHandler} implementations.
 *
 * <h3><code>http://xml.org/sax/features/namespace-prefixes</code></h3>
 * <p>
 * This feature controls how a {@link ValidatorHandler} introduces
 * namespace bindings that were not present in the original SAX event
 * stream.
 * When this feature is set to true, it must make
 * sure that the user's {@link ContentHandler} will see
 * the corresponding <code>xmlns*</code> attribute in
 * the {@link org.xml.sax.Attributes} object of the
 * {@link ContentHandler#startElement(String,String,String,Attributes)}
 * callback. Otherwise, <code>xmlns*</code> attributes must not be
 * added to {@link org.xml.sax.Attributes} that's passed to the
 * user-specified {@link ContentHandler}.
 * <p>
 * (Note that regardless of this switch, namespace bindings are
 * always notified to applications through
 * {@link ContentHandler#startPrefixMapping(String,String)} and
 * {@link ContentHandler#endPrefixMapping(String)} methods of the
 * {@link ContentHandler} specified by the user.)
 *
 * <p>
 * Note that this feature does <em>NOT</em> affect the way
 * a {@link ValidatorHandler} receives SAX events. It merely
 * changes the way it augments SAX events.
 *
 * <p>This feature is set to <code>false</code> by default.</p>
 *
 * @author  Kohsuke Kawaguchi
 * @since 1.5
 */
public abstract class ValidatorHandler implements ContentHandler {

    
Constructor for derived classes.


The constructor does nothing.


Derived classes must create ValidatorHandler objects that have null ErrorHandler and null LSResourceResolver.


/**
     * <p>Constructor for derived classes.</p>
     *
     * <p>The constructor does nothing.</p>
     *
     * <p>Derived classes must create {@link ValidatorHandler} objects that have
     * <code>null</code> {@link ErrorHandler} and
     * <code>null</code> {@link LSResourceResolver}.</p>
     */
    protected ValidatorHandler() {
    }

    
Sets the ContentHandler which receives the augmented validation result. 
 When a ContentHandler is specified, a ValidatorHandler will work as a filter and basically copy the incoming events to the specified ContentHandler. 
 In doing so, a ValidatorHandler may modify the events, for example by adding defaulted attributes. 
 A ValidatorHandler may buffer events to certain extent, but to allow ValidatorHandler to be used by a parser, the following requirement has to be met. 
    
 
  1. When ContentHandler.startElement(String, String, String, Attributes), ContentHandler.endElement(String, String, String), ContentHandler.startDocument(), or ContentHandler.endDocument() are invoked on a ValidatorHandler, the same method on the user-specified ContentHandler must be invoked for the same event before the callback returns. 
  2. ValidatorHandler may not introduce new elements that were not present in the input. 
  3. ValidatorHandler may not remove attributes that were present in the input. 


 When a callback method on the specified ContentHandler throws an exception, the same exception object must be thrown from the ValidatorHandler. The ErrorHandler should not be notified of such an exception. 

This method can be called even during a middle of a validation.

Params:
/**
     * Sets the {@link ContentHandler} which receives
     * the augmented validation result.
     *
     * <p>
     * When a {@link ContentHandler} is specified, a
     * {@link ValidatorHandler} will work as a filter
     * and basically copy the incoming events to the
     * specified {@link ContentHandler}.
     *
     * <p>
     * In doing so, a {@link ValidatorHandler} may modify
     * the events, for example by adding defaulted attributes.
     *
     * <p>
     * A {@link ValidatorHandler} may buffer events to certain
     * extent, but to allow {@link ValidatorHandler} to be used
     * by a parser, the following requirement has to be met.
     *
     * <ol>
     *  <li>When
     *      {@link ContentHandler#startElement(String, String, String, Attributes)},
     *      {@link ContentHandler#endElement(String, String, String)},
     *      {@link ContentHandler#startDocument()}, or
     *      {@link ContentHandler#endDocument()}
     *      are invoked on a {@link ValidatorHandler},
     *      the same method on the user-specified {@link ContentHandler}
     *      must be invoked for the same event before the callback
     *      returns.
     *  <li>{@link ValidatorHandler} may not introduce new elements that
     *      were not present in the input.
     *
     *  <li>{@link ValidatorHandler} may not remove attributes that were
     *      present in the input.
     * </ol>
     *
     * <p>
     * When a callback method on the specified {@link ContentHandler}
     * throws an exception, the same exception object must be thrown
     * from the {@link ValidatorHandler}. The {@link ErrorHandler}
     * should not be notified of such an exception.
     *
     * <p>
     * This method can be called even during a middle of a validation.
     *
     * @param receiver
     *      A {@link ContentHandler} or a null value.
     */
    public abstract void setContentHandler(ContentHandler receiver);

    
Gets the ContentHandler which receives the augmented validation result. 
See Also:
Returns: This method returns the object that was last set through the getContentHandler() method, or null if that method has never been called since this ValidatorHandler has created.
/**
     * Gets the {@link ContentHandler} which receives the
     * augmented validation result.
     *
     * @return
     *      This method returns the object that was last set through
     *      the {@link #getContentHandler()} method, or null
     *      if that method has never been called since this {@link ValidatorHandler}
     *      has created.
     *
     * @see #setContentHandler(ContentHandler)
     */
    public abstract ContentHandler getContentHandler();

    
Sets the ErrorHandler to receive errors encountered during the validation. 
 Error handler can be used to customize the error handling process during a validation. When an ErrorHandler is set, errors found during the validation will be first sent to the ErrorHandler. 
 The error handler can abort further validation immediately by throwing SAXException from the handler. Or for example it can print an error to the screen and try to continue the validation by returning normally from the ErrorHandler 
 If any Throwable is thrown from an ErrorHandler, the same Throwable object will be thrown toward the root of the call stack. 
 ValidatorHandler is not allowed to throw SAXException without first reporting it to ErrorHandler. 
 When the ErrorHandler is null, the implementation will behave as if the following ErrorHandler is set: 
class DraconianErrorHandler implements ErrorHandler { public void fatalError( SAXParseException e ) throws SAXException { throw e; } public void error( SAXParseException e ) throws SAXException { throw e; } public void warning( SAXParseException e ) throws SAXException { // noop } } 


 When a new ValidatorHandler object is created, initially this field is set to null. 
Params:
  • errorHandler – 
     A new error handler to be set. This parameter can be null.
/**
     * Sets the {@link ErrorHandler} to receive errors encountered
     * during the validation.
     *
     * <p>
     * Error handler can be used to customize the error handling process
     * during a validation. When an {@link ErrorHandler} is set,
     * errors found during the validation will be first sent
     * to the {@link ErrorHandler}.
     *
     * <p>
     * The error handler can abort further validation immediately
     * by throwing {@link org.xml.sax.SAXException} from the handler. Or for example
     * it can print an error to the screen and try to continue the
     * validation by returning normally from the {@link ErrorHandler}
     *
     * <p>
     * If any {@link Throwable} is thrown from an {@link ErrorHandler},
     * the same {@link Throwable} object will be thrown toward the
     * root of the call stack.
     *
     * <p>
     * {@link ValidatorHandler} is not allowed to
     * throw {@link org.xml.sax.SAXException} without first reporting it to
     * {@link ErrorHandler}.
     *
     * <p>
     * When the {@link ErrorHandler} is null, the implementation will
     * behave as if the following {@link ErrorHandler} is set:
     * <pre>
     * class DraconianErrorHandler implements {@link ErrorHandler} {
     *     public void fatalError( {@link org.xml.sax.SAXParseException} e ) throws {@link org.xml.sax.SAXException} {
     *         throw e;
     *     }
     *     public void error( {@link org.xml.sax.SAXParseException} e ) throws {@link org.xml.sax.SAXException} {
     *         throw e;
     *     }
     *     public void warning( {@link org.xml.sax.SAXParseException} e ) throws {@link org.xml.sax.SAXException} {
     *         // noop
     *     }
     * }
     * </pre>
     *
     * <p>
     * When a new {@link ValidatorHandler} object is created, initially
     * this field is set to null.
     *
     * @param   errorHandler
     *      A new error handler to be set. This parameter can be null.
     */
    public abstract void setErrorHandler(ErrorHandler errorHandler);

    
Gets the current ErrorHandler set to this ValidatorHandler. 
See Also:
Returns: This method returns the object that was last set through the setErrorHandler(ErrorHandler) method, or null if that method has never been called since this ValidatorHandler has created.
/**
     * Gets the current {@link ErrorHandler} set to this {@link ValidatorHandler}.
     *
     * @return
     *      This method returns the object that was last set through
     *      the {@link #setErrorHandler(ErrorHandler)} method, or null
     *      if that method has never been called since this {@link ValidatorHandler}
     *      has created.
     *
     * @see #setErrorHandler(ErrorHandler)
     */
    public abstract ErrorHandler getErrorHandler();

    
Sets the LSResourceResolver to customize resource resolution while in a validation episode. 
 ValidatorHandler uses a LSResourceResolver when it needs to locate external resources while a validation, although exactly what constitutes "locating external resources" is up to each schema language. 
 When the LSResourceResolver is null, the implementation will behave as if the following LSResourceResolver is set: 
class DumbLSResourceResolver implements LSResourceResolver { public LSInput resolveResource( String publicId, String systemId, String baseURI) { return null; // always return null } } 


 If a LSResourceResolver throws a RuntimeException (or instances of its derived classes), then the ValidatorHandler will abort the parsing and the caller of the validate method will receive the same RuntimeException. 
 When a new ValidatorHandler object is created, initially this field is set to null. 
Params:
  • resourceResolver – 
     A new resource resolver to be set. This parameter can be null.
/**
     * Sets the {@link LSResourceResolver} to customize
     * resource resolution while in a validation episode.
     *
     * <p>
     * {@link ValidatorHandler} uses a {@link LSResourceResolver}
     * when it needs to locate external resources while a validation,
     * although exactly what constitutes "locating external resources" is
     * up to each schema language.
     *
     * <p>
     * When the {@link LSResourceResolver} is null, the implementation will
     * behave as if the following {@link LSResourceResolver} is set:
     * <pre>
     * class DumbLSResourceResolver implements {@link LSResourceResolver} {
     *     public {@link org.w3c.dom.ls.LSInput} resolveResource(
     *         String publicId, String systemId, String baseURI) {
     *
     *         return null; // always return null
     *     }
     * }
     * </pre>
     *
     * <p>
     * If a {@link LSResourceResolver} throws a {@link RuntimeException}
     *  (or instances of its derived classes),
     * then the {@link ValidatorHandler} will abort the parsing and
     * the caller of the <code>validate</code> method will receive
     * the same {@link RuntimeException}.
     *
     * <p>
     * When a new {@link ValidatorHandler} object is created, initially
     * this field is set to null.
     *
     * @param   resourceResolver
     *      A new resource resolver to be set. This parameter can be null.
     */
    public abstract void setResourceResolver(LSResourceResolver resourceResolver);

    
Gets the current LSResourceResolver set to this ValidatorHandler. 
See Also:
Returns: This method returns the object that was last set through the setResourceResolver(LSResourceResolver) method, or null if that method has never been called since this ValidatorHandler has created.
/**
     * Gets the current {@link LSResourceResolver} set to this {@link ValidatorHandler}.
     *
     * @return
     *      This method returns the object that was last set through
     *      the {@link #setResourceResolver(LSResourceResolver)} method, or null
     *      if that method has never been called since this {@link ValidatorHandler}
     *      has created.
     *
     * @see #setErrorHandler(ErrorHandler)
     */
    public abstract LSResourceResolver getResourceResolver();

    
Obtains the TypeInfoProvider implementation of this ValidatorHandler. 
 The obtained TypeInfoProvider can be queried during a parse to access the type information determined by the validator. 

Some schema languages do not define the notion of type,
for those languages, this method may not be supported.
However, to be compliant with this specification, implementations
for W3C XML Schema 1.0 must support this operation.

Returns: null if the validator / schema language does not support the notion of TypeInfo. Otherwise a non-null valid TypeInfoProvider.
/**
     * Obtains the {@link TypeInfoProvider} implementation of this
     * {@link ValidatorHandler}.
     *
     * <p>
     * The obtained {@link TypeInfoProvider} can be queried during a parse
     * to access the type information determined by the validator.
     *
     * <p>
     * Some schema languages do not define the notion of type,
     * for those languages, this method may not be supported.
     * However, to be compliant with this specification, implementations
     * for W3C XML Schema 1.0 must support this operation.
     *
     * @return
     *      null if the validator / schema language does not support
     *      the notion of {@link org.w3c.dom.TypeInfo}.
     *      Otherwise a non-null valid {@link TypeInfoProvider}.
     */
    public abstract TypeInfoProvider getTypeInfoProvider();


    
Look up the value of a feature flag.

The feature name is any fully-qualified URI. It is possible for a ValidatorHandler to recognize a feature name but temporarily be unable to return its value. Some feature values may be available only in specific contexts, such as before, during, or after a validation. 
Implementors are free (and encouraged) to invent their own features,
using names built on their own URIs.


Params:
  • name – The feature name, which is a non-null fully-qualified URI.
Throws:
See Also:
Returns:The current value of the feature (true or false).
/**
     * Look up the value of a feature flag.
     *
     * <p>The feature name is any fully-qualified URI.  It is
     * possible for a {@link ValidatorHandler} to recognize a feature name but
     * temporarily be unable to return its value.
     * Some feature values may be available only in specific
     * contexts, such as before, during, or after a validation.
     *
     * <p>Implementors are free (and encouraged) to invent their own features,
     * using names built on their own URIs.</p>
     *
     * @param name The feature name, which is a non-null fully-qualified URI.
     *
     * @return The current value of the feature (true or false).
     *
     * @throws SAXNotRecognizedException If the feature
     *   value can't be assigned or retrieved.
     * @throws SAXNotSupportedException When the
     *   {@link ValidatorHandler} recognizes the feature name but
     *   cannot determine its value at this time.
     * @throws NullPointerException When <code>name</code> is <code>null</code>.
     *
     * @see #setFeature(String, boolean)
     */
    public boolean getFeature(String name)
        throws SAXNotRecognizedException, SAXNotSupportedException {

        if (name == null) {
            throw new NullPointerException();
        }

        throw new SAXNotRecognizedException(name);
    }

    
Set a feature for this ValidatorHandler.


Feature can be used to control the way a ValidatorHandler parses schemas. The feature name is any fully-qualified URI. It is possible for a SchemaFactory to expose a feature value but to be unable to change the current value. Some feature values may be immutable or mutable only in specific contexts, such as before, during, or after a validation.


All implementations are required to support the XMLConstants.FEATURE_SECURE_PROCESSING feature. When the feature is:


    
  
  • 
    true: the implementation will limit XML processing to conform to implementation limits. Examples include entity expansion limits and XML Schema constructs that would consume large amounts of resources. If XML processing is limited for security reasons, it will be reported via a call to the registered ErrorHandler.fatalError(SAXParseException exception). See setErrorHandler(ErrorHandler errorHandler). 
    • 
  
  • 
    false: the implementation will processing XML according to the XML specifications without
    regard to possible implementation limits.
  
    • 



Params:
  • name – The feature name, which is a non-null fully-qualified URI.
  • value – The requested value of the feature (true or false).
Throws:
See Also:
/**
     * <p>Set a feature for this <code>ValidatorHandler</code>.</p>
     *
     * <p>Feature can be used to control the way a
     * {@link ValidatorHandler} parses schemas. The feature name is
     * any fully-qualified URI. It is possible for a
     * {@link SchemaFactory} to
     * expose a feature value but to be unable to change the current
     * value. Some feature values may be immutable or mutable only in
     * specific contexts, such as before, during, or after a
     * validation.</p>
     *
     * <p>All implementations are required to support the {@link javax.xml.XMLConstants#FEATURE_SECURE_PROCESSING} feature.
     * When the feature is:</p>
     * <ul>
     *   <li>
     *     <code>true</code>: the implementation will limit XML processing to conform to implementation limits.
     *     Examples include entity expansion limits and XML Schema constructs that would consume large amounts of resources.
     *     If XML processing is limited for security reasons, it will be reported via a call to the registered
     *    {@link ErrorHandler#fatalError(SAXParseException exception)}.
     *     See {@link #setErrorHandler(ErrorHandler errorHandler)}.
     *   </li>
     *   <li>
     *     <code>false</code>: the implementation will processing XML according to the XML specifications without
     *     regard to possible implementation limits.
     *   </li>
     * </ul>
     *
     * @param name The feature name, which is a non-null fully-qualified URI.
     * @param value The requested value of the feature (true or false).
     *
     * @throws SAXNotRecognizedException If the feature
     *   value can't be assigned or retrieved.
     * @throws SAXNotSupportedException When the
     *   {@link ValidatorHandler} recognizes the feature name but
     *   cannot set the requested value.
     * @throws NullPointerException When <code>name</code> is <code>null</code>.
     *
     * @see #getFeature(String)
     */
    public void setFeature(String name, boolean value)
        throws SAXNotRecognizedException, SAXNotSupportedException {

        if (name == null) {
            throw new NullPointerException();
        }

        throw new SAXNotRecognizedException(name);
    }

    
Set the value of a property.

The property name is any fully-qualified URI. It is possible for a ValidatorHandler to recognize a property name but to be unable to change the current value. Some property values may be immutable or mutable only in specific contexts, such as before, during, or after a validation.


ValidatorHandlers are not required to recognize setting any specific property names.


Params:
  • name – The property name, which is a non-null fully-qualified URI.
  • object – The requested value for the property.
Throws:
/**
     * Set the value of a property.
     *
     * <p>The property name is any fully-qualified URI.  It is
     * possible for a {@link ValidatorHandler} to recognize a property name but
     * to be unable to change the current value.
     * Some property values may be immutable or mutable only
     * in specific contexts, such as before, during, or after
     * a validation.</p>
     *
     * <p>{@link ValidatorHandler}s are not required to recognize setting
     * any specific property names.</p>
     *
     * @param name The property name, which is a non-null fully-qualified URI.
     * @param object The requested value for the property.
     *
     * @throws SAXNotRecognizedException If the property
     *   value can't be assigned or retrieved.
     * @throws SAXNotSupportedException When the
     *   {@link ValidatorHandler} recognizes the property name but
     *   cannot set the requested value.
     * @throws NullPointerException When <code>name</code> is <code>null</code>.
     */
    public void setProperty(String name, Object object)
        throws SAXNotRecognizedException, SAXNotSupportedException {

        if (name == null) {
            throw new NullPointerException();
        }

        throw new SAXNotRecognizedException(name);
    }

    
Look up the value of a property.

The property name is any fully-qualified URI. It is possible for a ValidatorHandler to recognize a property name but temporarily be unable to return its value. Some property values may be available only in specific contexts, such as before, during, or after a validation.


ValidatorHandlers are not required to recognize any specific property names.


Implementors are free (and encouraged) to invent their own properties,
using names built on their own URIs.


Params:
  • name – The property name, which is a non-null fully-qualified URI.
Throws:
See Also:
Returns:The current value of the property.
/**
     * Look up the value of a property.
     *
     * <p>The property name is any fully-qualified URI.  It is
     * possible for a {@link ValidatorHandler} to recognize a property name but
     * temporarily be unable to return its value.
     * Some property values may be available only in specific
     * contexts, such as before, during, or after a validation.</p>
     *
     * <p>{@link ValidatorHandler}s are not required to recognize any specific
     * property names.</p>
     *
     * <p>Implementors are free (and encouraged) to invent their own properties,
     * using names built on their own URIs.</p>
     *
     * @param name The property name, which is a non-null fully-qualified URI.
     *
     * @return The current value of the property.
     *
     * @throws SAXNotRecognizedException If the property
     *   value can't be assigned or retrieved.
     * @throws SAXNotSupportedException When the
     *   XMLReader recognizes the property name but
     *   cannot determine its value at this time.
     * @throws NullPointerException When <code>name</code> is <code>null</code>.
     *
     * @see #setProperty(String, Object)
     */
    public Object getProperty(String name)
        throws SAXNotRecognizedException, SAXNotSupportedException {

        if (name == null) {
            throw new NullPointerException();
        }

        throw new SAXNotRecognizedException(name);
    }
}