/*

 * Copyright 2000-2006 Sun Microsystems, Inc.  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.  Sun designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Sun in the LICENSE file that accompanied this code.

 *

 * 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,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

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 <a href="mailto:Jeff.Suttor@Sun.com">Jeff Suttor</a>

 * @author <a href="mailto:Neeraj.Bajaj@sun.com">Neeraj Bajaj</a>

 *

 *

 */

public abstract class SAXParserFactory {

    /** The default property name according to the JAXP spec */

    private static final String DEFAULT_PROPERTY_NAME = "javax.xml.parsers.SAXParserFactory";

    /**

     * <p>Should Parsers be validating?</p>

     */

    private boolean validating = false;

    /**

     * <p>Should Parsers be namespace aware?</p>

     */

    private boolean namespaceAware = false;

    /**

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

     */

    protected 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 <code>System.err</code> about what it is doing and where it is looking at.</p>

     *

     * <p> If you have problems loading {@link DocumentBuilder}s, try:</p>

     * <pre>

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

     * </pre>

     *

     *

     * @return A new instance of a SAXParserFactory.

     *

     * @throws 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 */

                "com.sun.org.apache.xerces.internal.jaxp.SAXParserFactoryImpl");

        } catch (FactoryFinder.ConfigurationError e) {

            throw new FactoryConfigurationError(e.getException(),

                                                e.getMessage());

        }

    }

    /**

     * <p>Obtain a new instance of a <code>SAXParserFactory</code> from class name.

     * This function is useful when there are multiple providers in the classpath.

     * It gives more control to the application as it can specify which provider

     * should be loaded.</p>

     *

     * <p>Once an application has obtained a reference to a <code>SAXParserFactory</code>

     * it can use the factory to configure and obtain parser instances.</p>

     *

     *

     * <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 <code>System.err</code> about what it is doing and where it is looking at.</p>

     *

     * <p> If you have problems, try:</p>

     * <pre>

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

     * </pre>

     *

     * @param factoryClassName fully qualified factory class name that provides implementation of <code>javax.xml.parsers.SAXParserFactory</code>.

     *

     * @param classLoader <code>ClassLoader</code> used to load the factory class. If <code>null</code>

     *                     current <code>Thread</code>'s context classLoader is used to load the factory class.

     *

     * @return New instance of a <code>SAXParserFactory</code>

     *

     * @throws FactoryConfigurationError if <code>factoryClassName</code> is <code>null</code>, or

     *                                   the factory class cannot be loaded, instantiated.

     *

     * @see #newInstance()

     *

     * @since 1.6

     */

    public static SAXParserFactory newInstance(String factoryClassName, ClassLoader classLoader){

        try {

            //do not fallback if given classloader can't find the class, throw exception

            return (SAXParserFactory) FactoryFinder.newInstance(factoryClassName, classLoader, false);

        } catch (FactoryFinder.ConfigurationError e) {

            throw new FactoryConfigurationError(e.getException(),

                                                e.getMessage());

        }

    }

    /**

     * <p>Creates a new instance of a SAXParser using the currently

     * configured factory parameters.</p>

     *

     * @return A new instance of a SAXParser.

     *

     * @throws ParserConfigurationException if a parser cannot

     *   be created which satisfies the requested configuration.

     * @throws 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 <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 <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.)

     * </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 <code>false</code>, 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.

     *

     * @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.

     *

     * @return true if the factory is configured to produce parsers which validate

     *         the XML content during parse; false otherwise.

     */

    public boolean isValidating() {

        return validating;

    }

    /**

     *

     * <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 enity 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.

     *

     * @throws ParserConfigurationException if a parser cannot

     *     be created which satisfies the requested configuration.

     * @throws SAXNotRecognizedException When the underlying XMLReader does

     *            not recognize the property name.

     * @throws 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;

    /**

     *

     * <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.

     *

     * @throws ParserConfigurationException if a parser cannot be created which satisfies the requested configuration.

     * @throws SAXNotRecognizedException When the underlying XMLReader does not recognize the property name.

     * @throws 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;

    /* <p>Get current state of canonicalization.</p>

     *

     * @return current state canonicalization control

     */

    /*

    public boolean getCanonicalization() {

        return canonicalState;

    }

    */

    /**

     * Gets the {@link Schema} object specified through

     * the {@link #setSchema(Schema schema)} method.

     *

     *

     * @throws UnsupportedOperationException When implementation does not

     *   override this method

     *

     * @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()

            + "\""

            );

    }

    /** <p>Set canonicalization control to <code>true</code> or

     * </code>false</code>.</p>

     *

     * @param state of canonicalization

     */

    /*

    public void setCanonicalization(boolean state) {

        canonicalState = state;

    }

    */

    /**

     * <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>Initialy, <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 implmentors</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 When implementation does not

     *   override this method

     *

     * @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()

            + "\""

            );

    }

    /**

     * <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 When implementation does not

     *   override this method

     *

     * @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()

            + "\""

            );

    }

    /**

     * <p>Get state of XInclude processing.</p>

     *

     * @return current state of XInclude processing

     *

     * @throws UnsupportedOperationException When implementation does not

     *   override this method

     *

     * @since 1.5

     */

    public boolean isXIncludeAware() {

        throw new UnsupportedOperationException(

            "This parser does not support specification \""

            + this.getClass().getPackage().getSpecificationTitle()

            + "\" version \""

            + this.getClass().getPackage().getSpecificationVersion()

            + "\""

            );

    }

}