http://xml.apache.org/commons/components/external/: xml-commons provides an Apache-hosted set of DOM, SAX, and JAXP interfaces for use in other xml-based projects. Our hope is that we can standardize on both a common version and packaging scheme for these critical XML standards interfaces to make the lives of both our developers and users easier. The External Components portion of xml-commons contains interfaces that are defined by external standards organizations. For DOM, that's the W3C; for SAX it's David Megginson and sax.sourceforge.net; for JAXP it's Sun. 
/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
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// $Id: SAXParserFactory.java 884950 2009-11-27 18:46:18Z mrglavas $

package javax.xml.parsers;

import javax.xml.validation.Schema;

import org.xml.sax.SAXException;
import org.xml.sax.SAXNotRecognizedException;
import org.xml.sax.SAXNotSupportedException;


Defines a factory API that enables applications to configure and
obtain a SAX based parser to parse XML documents.

Author:Jeff Suttor
Version:$Revision: 884950 $, $Date: 2009-11-27 13:46:18 -0500 (Fri, 27 Nov 2009) $
/**
 * Defines a factory API that enables applications to configure and
 * obtain a SAX based parser to parse XML documents.
 *
 * @author <a href="Jeff.Suttor@Sun.com">Jeff Suttor</a>
 * @version $Revision: 884950 $, $Date: 2009-11-27 13:46:18 -0500 (Fri, 27 Nov 2009) $
 */
public abstract class SAXParserFactory {

    
Should Parsers be validating?


/**
     * <p>Should Parsers be validating?</p>
     */
    private boolean validating = false;
    
    
Should Parsers be namespace aware?


/**
     * <p>Should Parsers be namespace aware?</p>
     */
    private boolean namespaceAware = false;
    
    
Protected constructor to force use of newInstance().


/**
     * <p>Protected constructor to force use of {@link #newInstance()}.</p>
     */
    protected SAXParserFactory () {
    
    }

    
Obtain a new instance of a SAXParserFactory. This
static method creates a new factory instance
This method uses the following ordered lookup procedure to determine
the SAXParserFactory implementation class to
load:

    

  • 
Use the javax.xml.parsers.SAXParserFactory system
property.

    • 

  • 
Use the properties file "lib/jaxp.properties" in the JRE directory.
This configuration file is in standard java.util.Properties
 format and contains the fully qualified name of the
implementation class with the key being the system property defined
above.
The jaxp.properties file is read only once by the JAXP implementation
and it's values are then cached for future use.  If the file does not exist
when the first attempt is made to read from it, no further attempts are
made to check for its existence.  It is not possible to change the value
of any property in jaxp.properties after it has been read for the first time.

    • 

  • 
Use the Services API (as detailed in the JAR specification), if
available, to determine the classname. The Services API will look
for a classname in the file
META-INF/services/javax.xml.parsers.SAXParserFactory
in jars available to the runtime.

    • 

  • 
Platform default SAXParserFactory instance.

    • 


Once an application has obtained a reference to a
SAXParserFactory it can use the factory to
configure and obtain parser instances.

Tip for Trouble-shooting


Setting the jaxp.debug system property will cause
this method to print a lot of debug messages
to System.err about what it is doing and where it is looking at.


 If you have problems loading SAXParsers, try:


java -Djaxp.debug=1 YourProgram ....



Throws:
Returns:A new instance of a SAXParserFactory.
/**
     * Obtain a new instance of a <code>SAXParserFactory</code>. This
     * static method creates a new factory instance
     * This method uses the following ordered lookup procedure to determine
     * the <code>SAXParserFactory</code> implementation class to
     * load:
     * <ul>
     * <li>
     * Use the <code>javax.xml.parsers.SAXParserFactory</code> system
     * property.
     * </li>
     * <li>
     * Use the properties file "lib/jaxp.properties" in the JRE directory.
     * This configuration file is in standard <code>java.util.Properties
     * </code> format and contains the fully qualified name of the
     * implementation class with the key being the system property defined
     * above.
     * 
     * The jaxp.properties file is read only once by the JAXP implementation
     * and it's values are then cached for future use.  If the file does not exist
     * when the first attempt is made to read from it, no further attempts are
     * made to check for its existence.  It is not possible to change the value
     * of any property in jaxp.properties after it has been read for the first time.
     * </li>
     * <li>
     * Use the Services API (as detailed in the JAR specification), if
     * available, to determine the classname. The Services API will look
     * for a classname in the file
     * <code>META-INF/services/javax.xml.parsers.SAXParserFactory</code>
     * in jars available to the runtime.
     * </li>
     * <li>
     * Platform default <code>SAXParserFactory</code> instance.
     * </li>
     * </ul>
     *
     * Once an application has obtained a reference to a
     * <code>SAXParserFactory</code> it can use the factory to
     * configure and obtain parser instances.
     * 
     * 
     * 
     * <h2>Tip for Trouble-shooting</h2>
     * <p>Setting the <code>jaxp.debug</code> system property will cause
     * this method to print a lot of debug messages
     * to <tt>System.err</tt> about what it is doing and where it is looking at.</p>
     * 
     * <p> If you have problems loading {@link SAXParser}s, try:</p>
     * <pre>
     * java -Djaxp.debug=1 YourProgram ....
     * </pre>
     * 
     * 
     * @return A new instance of a SAXParserFactory.
     *
     * @exception FactoryConfigurationError if the implementation is
     * not available or cannot be instantiated.
     */

    public static SAXParserFactory newInstance() {
        try {
            return (SAXParserFactory) FactoryFinder.find(
                /* The default property name according to the JAXP spec */
                "javax.xml.parsers.SAXParserFactory",
                /* The fallback implementation class name */
                "org.apache.xerces.jaxp.SAXParserFactoryImpl");
        } 
        catch (FactoryFinder.ConfigurationError e) {
            throw new FactoryConfigurationError(e.getException(), e.getMessage());
        }
    }
    
    
Throws:
Returns:A new instance of a SAXParserFactory.
/**
     * @return A new instance of a SAXParserFactory.
     *
     * @exception FactoryConfigurationError if the implementation is
     * not available or cannot be instantiated.
     */
    public static SAXParserFactory newInstance(String factoryClassName,
            ClassLoader classLoader) {
        if (factoryClassName == null) {
            throw new FactoryConfigurationError("factoryClassName cannot be null.");
        }
        if (classLoader == null) {
            classLoader = SecuritySupport.getContextClassLoader();
        }
        try {
            return (SAXParserFactory) FactoryFinder.newInstance(factoryClassName, classLoader, false);
        }
        catch (FactoryFinder.ConfigurationError e) {
            throw new FactoryConfigurationError(e.getException(), e.getMessage());
        }
    }
    
    
Creates a new instance of a SAXParser using the currently
configured factory parameters.


Throws:
Returns:A new instance of a SAXParser.
/**
     * <p>Creates a new instance of a SAXParser using the currently
     * configured factory parameters.</p>
     *
     * @return A new instance of a SAXParser.
     *
     * @exception ParserConfigurationException if a parser cannot
     *   be created which satisfies the requested configuration.
     * @exception SAXException for SAX errors.
     */
    
    public abstract SAXParser newSAXParser()
        throws ParserConfigurationException, SAXException;

    
    
Specifies that the parser produced by this code will
provide support for XML namespaces. By default the value of this is set
to false.

Params:
  • awareness – true if the parser produced by this code will
                 provide support for XML namespaces; false otherwise.
/**
     * Specifies that the parser produced by this code will
     * provide support for XML namespaces. By default the value of this is set
     * to <code>false</code>.
     *
     * @param awareness true if the parser produced by this code will
     *                  provide support for XML namespaces; false otherwise.
     */
    
    public void setNamespaceAware(boolean awareness) {
        this.namespaceAware = awareness;
    }

    
Specifies that the parser produced by this code will
validate documents as they are parsed. By default the value of this is
set to false.


Note that "the validation" here means
a validating
parser as defined in the XML recommendation.
In other words, it essentially just controls the DTD validation.
(except the legacy two properties defined in JAXP 1.2.
See here for more details.)



 To use modern schema languages such as W3C XML Schema or RELAX NG instead of DTD, you can configure your parser to be a non-validating parser by leaving the setValidating(boolean) method false, then use the setSchema(Schema) method to associate a schema to a parser. 


Params:
  • validating – true if the parser produced by this code will
                  validate documents as they are parsed; false otherwise.
/**
     * Specifies that the parser produced by this code will
     * validate documents as they are parsed. By default the value of this is
     * set to <code>false</code>.
     * 
     * <p>
     * Note that "the validation" here means
     * <a href="http://www.w3.org/TR/REC-xml#proc-types">a validating
     * parser</a> as defined in the XML recommendation.
     * In other words, it essentially just controls the DTD validation.
     * (except the legacy two properties defined in JAXP 1.2.
     * See <a href="#validationCompatibility">here</a> for more details.)
     * </p>
     * 
     * <p>
     * To use modern schema languages such as W3C XML Schema or
     * RELAX NG instead of DTD, you can configure your parser to be
     * a non-validating parser by leaving the {@link #setValidating(boolean)}
     * method <tt>false</tt>, then use the {@link #setSchema(Schema)}
     * method to associate a schema to a parser.
     * </p>
     *
     * @param validating true if the parser produced by this code will
     *                   validate documents as they are parsed; false otherwise.
     */
    
    public void setValidating(boolean validating) {
        this.validating = validating;
    }

    
Indicates whether or not the factory is configured to produce
parsers which are namespace aware.

Returns:true if the factory is configured to produce
        parsers which are namespace aware; false otherwise.
/**
     * Indicates whether or not the factory is configured to produce
     * parsers which are namespace aware.
     *
     * @return true if the factory is configured to produce
     *         parsers which are namespace aware; false otherwise.
     */
    
    public boolean isNamespaceAware() {
        return namespaceAware;
    }

    
Indicates whether or not the factory is configured to produce
parsers which validate the XML content during parse.

Returns:true if the factory is configured to produce parsers which validate
        the XML content during parse; false otherwise.
/**
     * Indicates whether or not the factory is configured to produce
     * parsers which validate the XML content during parse.
     *
     * @return true if the factory is configured to produce parsers which validate
     *         the XML content during parse; false otherwise.
     */
    
    public boolean isValidating() {
        return validating;
    }

    
Sets the particular feature in the underlying implementation of
org.xml.sax.XMLReader.
A list of the core features and properties can be found at
http://www.saxproject.org/


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 SAXParser parse methods for handler specification.
  
    • 
  
  • 
    When the feature is false, the implementation will processing XML according to the XML specifications without
    regard to possible implementation limits.
  
    • 



Params:
  • name – The name of the feature to be set.
  • value – The value of the feature to be set.
Throws:
See Also:
/**
     *
     * <p>Sets the particular feature in the underlying implementation of
     * org.xml.sax.XMLReader.
     * A list of the core features and properties can be found at
     * <a href="http://www.saxproject.org/">http://www.saxproject.org/</a></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 org.xml.sax.ErrorHandler#fatalError(SAXParseException exception)}.
	 *     See {@link SAXParser} <code>parse</code> methods for handler specification.
	 *   </li>
	 *   <li>
	 *     When the feature is <code>false</code>, the implementation will processing XML according to the XML specifications without
	 *     regard to possible implementation limits.
	 *   </li>
	 * </ul>
	 * 
     * @param name The name of the feature to be set.
     * @param value The value of the feature to be set.
     * 
     * @exception ParserConfigurationException if a parser cannot
     *     be created which satisfies the requested configuration.
     * @exception SAXNotRecognizedException When the underlying XMLReader does
     *            not recognize the property name.
     * @exception SAXNotSupportedException When the underlying XMLReader
     *            recognizes the property name but doesn't support the
     *            property.
     * @throws NullPointerException If the <code>name</code> parameter is null.
     *
     * @see org.xml.sax.XMLReader#setFeature
     */
    public abstract void setFeature(String name, boolean value)
        throws ParserConfigurationException, SAXNotRecognizedException,
                SAXNotSupportedException;

    
Returns the particular property requested for in the underlying
implementation of org.xml.sax.XMLReader.


Params:
  • name – The name of the property to be retrieved.
Throws:
See Also:
Returns:Value of the requested property.
/**
     *
     * <p>Returns the particular property requested for in the underlying
     * implementation of org.xml.sax.XMLReader.</p>
     *
     * @param name The name of the property to be retrieved.
     * 
     * @return Value of the requested property.
     *
     * @exception ParserConfigurationException if a parser cannot be created which satisfies the requested configuration.
     * @exception SAXNotRecognizedException When the underlying XMLReader does not recognize the property name.
     * @exception SAXNotSupportedException When the underlying XMLReader recognizes the property name but doesn't support the property.
     *
     * @see org.xml.sax.XMLReader#getProperty
     */
    public abstract boolean getFeature(String name)
        throws ParserConfigurationException, SAXNotRecognizedException,
                SAXNotSupportedException;
    
    
Gets the Schema object specified through the setSchema(Schema schema) method. 
Throws:
  • UnsupportedOperationException – 
     For backward compatibility, when implementations for
     earlier versions of JAXP is used, this exception will be
     thrown.
Returns: the Schema object that was last set through the setSchema(Schema) method, or null if the method was not invoked since a SAXParserFactory is created.
Since:1.5
/**
     * Gets the {@link Schema} object specified through
     * the {@link #setSchema(Schema schema)} method.
     * 
     * 
     * @throws UnsupportedOperationException
     *      For backward compatibility, when implementations for
     *      earlier versions of JAXP is used, this exception will be
     *      thrown.
     * 
     * @return

     *      the {@link Schema} object that was last set through
     *      the {@link #setSchema(Schema)} method, or null
     *      if the method was not invoked since a {@link SAXParserFactory}
     *      is created.
     * 
     * @since 1.5
     */
    public Schema getSchema() {
        throw new UnsupportedOperationException(
            "This parser does not support specification \""
            + this.getClass().getPackage().getSpecificationTitle()
            + "\" version \""
            + this.getClass().getPackage().getSpecificationVersion()
            + "\""
            );
    }
    
    
Set the Schema to be used by parsers created from this factory.


When a Schema is non-null, a parser will use a validator created from it to validate documents before it passes information down to the application.


When warnings/errors/fatal errors are found by the validator, the parser must handle them as if those errors were found by the parser itself. In other words, if the user-specified ErrorHandler is set, it must receive those errors, and if not, they must be treated according to the implementation specific default error handling rules. 
A validator may modify the SAX event stream (for example by
adding default values that were missing in documents), and a parser
is responsible to make sure that the application will receive
those modified event stream.
  

Initially, null is set as the Schema.
 

This processing will take effect even if the isValidating() method returns false.

It is an error to use
the http://java.sun.com/xml/jaxp/properties/schemaSource
property and/or the http://java.sun.com/xml/jaxp/properties/schemaLanguage property in conjunction with a non-null Schema object. Such configuration will cause a SAXException exception when those properties are set on a SAXParser.


Note for implementors


 A parser must be able to work with any Schema implementation. However, parsers and schemas are allowed to use implementation-specific custom mechanisms as long as they yield the result described in the specification. 


Params:
  • schema – Schema to use, null to remove a schema.
Throws:
  • UnsupportedOperationException – 
     For backward compatibility, when implementations for
     earlier versions of JAXP is used, this exception will be
     thrown.
Since:1.5
/**
     * <p>Set the {@link Schema} to be used by parsers created
     * from this factory.</p>
     * 
     * <p>When a {@link Schema} is non-null, a parser will use a validator
     * created from it to validate documents before it passes information
     * down to the application.</p>
     * 
     * <p>When warnings/errors/fatal errors are found by the validator, the parser must
     * handle them as if those errors were found by the parser itself. 
     * In other words, if the user-specified {@link org.xml.sax.ErrorHandler}
     * is set, it must receive those errors, and if not, they must be
     * treated according to the implementation specific
     * default error handling rules.
     * 
     * <p>A validator may modify the SAX event stream (for example by
     * adding default values that were missing in documents), and a parser
     * is responsible to make sure that the application will receive
     * those modified event stream.</p>  
     * 
     * <p>Initially, <code>null</code> is set as the {@link Schema}.</p> 
     * 
     * <p>This processing will take effect even if
     * the {@link #isValidating()} method returns <code>false</code>.
     * 
     * <p>It is an error to use
     * the <code>http://java.sun.com/xml/jaxp/properties/schemaSource</code>
     * property and/or the <code>http://java.sun.com/xml/jaxp/properties/schemaLanguage</code>
     * property in conjunction with a non-null {@link Schema} object.
     * Such configuration will cause a {@link SAXException}
     * exception when those properties are set on a {@link SAXParser}.</p>
     * 
     * <h4>Note for implementors</h4>
     * <p>
     * A parser must be able to work with any {@link Schema}
     * implementation. However, parsers and schemas are allowed
     * to use implementation-specific custom mechanisms
     * as long as they yield the result described in the specification.
     * </p>
     * 
     * @param schema <code>Schema</code> to use, <code>null</code> to remove a schema.
     * 
     * @throws UnsupportedOperationException
     *      For backward compatibility, when implementations for
     *      earlier versions of JAXP is used, this exception will be
     *      thrown.
     * 
     * @since 1.5
     */
    public void setSchema(Schema schema) {
        throw new UnsupportedOperationException(
            "This parser does not support specification \""
            + this.getClass().getPackage().getSpecificationTitle()
            + "\" version \""
            + this.getClass().getPackage().getSpecificationVersion()
            + "\""
            );
    }

    
Set state of XInclude processing.


If XInclude markup is found in the document instance, should it be
processed as specified in 
XML Inclusions (XInclude) Version 1.0.


XInclude processing defaults to false.


Params:
  • state – Set XInclude processing to true or
  false
Throws:
  • UnsupportedOperationException – 
     For backward compatibility, when implementations for
     earlier versions of JAXP is used, this exception will be
     thrown.
Since:1.5
/**
     * <p>Set state of XInclude processing.</p>
     * 
     * <p>If XInclude markup is found in the document instance, should it be
     * processed as specified in <a href="http://www.w3.org/TR/xinclude/">
     * XML Inclusions (XInclude) Version 1.0</a>.</p>
     * 
     * <p>XInclude processing defaults to <code>false</code>.</p>
     * 
     * @param state Set XInclude processing to <code>true</code> or
     *   <code>false</code>
     * 
     * @throws UnsupportedOperationException
     *      For backward compatibility, when implementations for
     *      earlier versions of JAXP is used, this exception will be
     *      thrown.
     * 
     * @since 1.5
     */
    public void setXIncludeAware(final boolean state) {
        throw new UnsupportedOperationException(
            "This parser does not support specification \""
            + this.getClass().getPackage().getSpecificationTitle()
            + "\" version \""
            + this.getClass().getPackage().getSpecificationVersion()
            + "\""
            );
    }

    
Get state of XInclude processing.


Throws:
  • UnsupportedOperationException – 
     For backward compatibility, when implementations for
     earlier versions of JAXP is used, this exception will be
     thrown.
Returns:current state of XInclude processing
Since:1.5
/**
     * <p>Get state of XInclude processing.</p>
     * 
     * @return current state of XInclude processing
     * 
     * @throws UnsupportedOperationException
     *      For backward compatibility, when implementations for
     *      earlier versions of JAXP is used, this exception will be
     *      thrown.
     * 
     * @since 1.5
     */
    public boolean isXIncludeAware() {
        throw new UnsupportedOperationException(
            "This parser does not support specification \""
            + this.getClass().getPackage().getSpecificationTitle()
            + "\" version \""
            + this.getClass().getPackage().getSpecificationVersion()
            + "\""
            );
    }
}