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 * 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

 * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 */

package org.xml.sax;

/**

 * Basic interface for SAX error handlers.

 *

 * <p>If a SAX application needs to implement customized error

 * handling, it must implement this interface and then register an

 * instance with the XML reader using the

 * {@link org.xml.sax.XMLReader#setErrorHandler setErrorHandler}

 * method.  The parser will then report all errors and warnings

 * through this interface.</p>

 *

 * <p><strong>WARNING:</strong> If an application does <em>not</em>

 * register an ErrorHandler, XML parsing errors will go unreported,

 * except that <em>SAXParseException</em>s will be thrown for fatal errors.

 * In order to detect validity errors, an ErrorHandler that does something

 * with {@link #error error()} calls must be registered.</p>

 *

 * <p>For XML processing errors, a SAX driver must use this interface

 * in preference to throwing an exception: it is up to the application

 * to decide whether to throw an exception for different types of

 * errors and warnings.  Note, however, that there is no requirement that

 * the parser continue to report additional errors after a call to

 * {@link #fatalError fatalError}.  In other words, a SAX driver class

 * may throw an exception after reporting any fatalError.

 * Also parsers may throw appropriate exceptions for non-XML errors.

 * For example, {@link XMLReader#parse XMLReader.parse()} would throw

 * an IOException for errors accessing entities or the document.</p>

 *

 * @since 1.4, SAX 1.0

 * @author David Megginson

 * @see org.xml.sax.XMLReader#setErrorHandler

 * @see org.xml.sax.SAXParseException

 */

public interface ErrorHandler {

    /**

     * Receive notification of a warning.

     *

     * <p>SAX parsers will use this method to report conditions that

     * are not errors or fatal errors as defined by the XML

     * recommendation.  The default behaviour is to take no

     * action.</p>

     *

     * <p>The SAX parser must continue to provide normal parsing events

     * after invoking this method: it should still be possible for the

     * application to process the document through to the end.</p>

     *

     * <p>Filters may use this method to report other, non-XML warnings

     * as well.</p>

     *

     * @param exception The warning information encapsulated in a

     *                  SAX parse exception.

     * @exception org.xml.sax.SAXException Any SAX exception, possibly

     *            wrapping another exception.

     * @see org.xml.sax.SAXParseException

     */

    public abstract void warning (SAXParseException exception)

        throws SAXException;

    /**

     * Receive notification of a recoverable error.

     *

     * <p>This corresponds to the definition of "error" in section 1.2

     * of the W3C XML 1.0 Recommendation.  For example, a validating

     * parser would use this callback to report the violation of a

     * validity constraint.  The default behaviour is to take no

     * action.</p>

     *

     * <p>The SAX parser must continue to provide normal parsing

     * events after invoking this method: it should still be possible

     * for the application to process the document through to the end.

     * If the application cannot do so, then the parser should report

     * a fatal error even if the XML recommendation does not require

     * it to do so.</p>

     *

     * <p>Filters may use this method to report other, non-XML errors

     * as well.</p>

     *

     * @param exception The error information encapsulated in a

     *                  SAX parse exception.

     * @exception org.xml.sax.SAXException Any SAX exception, possibly

     *            wrapping another exception.

     * @see org.xml.sax.SAXParseException

     */

    public abstract void error (SAXParseException exception)

        throws SAXException;

    /**

     * Receive notification of a non-recoverable, fatal error.

     *

     * <p>

     * As defined in section 1.2 of the W3C XML 1.0 Recommendation, fatal errors

     * are those that would make it impossible for a parser to continue normal

     * processing. These include violation of a well-formedness constraint,

     * invalid encoding, and forbidden structural errors as described in the

     * W3C XML 1.0 Recommendation.

     *

     * @apiNote An application must assume that the parser can no longer perform

     * normal processing after reporting a fatal error and may stop by throwing

     * a {@link SAXException} without calling {@link ContentHandler#endDocument()}.

     * In addition, the parser cannot be expected to be able to return accurate

     * information about the logical structure on the rest of the document even

     * if it may be able to resume parsing.

     *

     * @implNote After invoking this method, the parser may stop processing by

     * throwing a {@link SAXException}, or implement a feature that can direct

     * it to continue after a fatal error. In the later case, it may report

     * events on the rest of the document without any guarantee of correctness.

     *

     * @param exception The error information encapsulated in a

     *                  {@link SAXParseException}.

     * @throws SAXException if the application chooses to discontinue the parsing

     */

    public abstract void fatalError (SAXParseException exception)

        throws SAXException;

}

// end of ErrorHandler.java