001/*
002 * ============================================================================
003 * Copyright © 2002-2021 by Thomas Thrien.
004 * All Rights Reserved.
005 * ============================================================================
006 * Licensed to the public under the agreements of the GNU Lesser General Public
007 * License, version 3.0 (the "License"). You may obtain a copy of the License at
008 *
009 *      http://www.gnu.org/licenses/lgpl.html
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
013 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
014 * License for the specific language governing permissions and limitations
015 * under the License.
016 */
017
018package org.tquadrat.foundation.xml.parse;
019
020import static org.apiguardian.api.API.Status.STABLE;
021
022import org.apiguardian.api.API;
023import org.tquadrat.foundation.annotation.ClassVersion;
024import org.xml.sax.ErrorHandler;
025import org.xml.sax.SAXParseException;
026
027/**
028 *  <p>{@summary This implementation for a
029 *  {@linkplain ErrorHandler XML Error handler}
030 *  swallows the error messages.} The methods</p>
031 *  <ul>
032 *      <li>{@link #error(SAXParseException) error()}</li>
033 *      <li>{@link #fatalError(SAXParseException) fatalError()}</li>
034 *      <li>{@link #warning(SAXParseException) warning()}</li>
035 *  </ul>
036 *  <p>have an empty body.</p>
037 *  <p>This error handler is useful when really no internal error handling is
038 *  desired; calling
039 *  {@link javax.xml.parsers.DocumentBuilder#setErrorHandler(ErrorHandler)}
040 *  with {@code null} as argument will activate a built-in error handler with
041 *  an unpredictable behaviour.</p>
042 *  <p>The one and only instance for this class can be obtained using the
043 *  {@link #INSTANCE}
044 *  constant.</p>
045 *  <p>This simple initialisation pattern was chosen instead of a full
046 *  Singleton setup because the error handler does not maintain a state.</p>
047 *
048 *  @extauthor Thomas Thrien - thomas.thrien@tquadrat.org
049 *  @version $Id: NullErrorHandler.java 895 2021-04-05 12:40:34Z tquadrat $
050 *  @since 0.1.0
051 *
052 *  @see    org.tquadrat.foundation.xml.stringconverter.DocumentStringConverter
053 *
054 *  @UMLGraph.link
055 */
056@ClassVersion( sourceVersion = "$Id: NullErrorHandler.java 895 2021-04-05 12:40:34Z tquadrat $" )
057@API( status = STABLE, since = "0.1.0" )
058public final class NullErrorHandler implements ErrorHandler
059{
060        /*------------------------*\
061    ====** Static Initialisations **===========================================
062        \*------------------------*/
063    /**
064     *  The one and only instance of this class.
065     */
066    public static final NullErrorHandler INSTANCE = new NullErrorHandler();
067
068        /*--------------*\
069    ====** Constructors **=====================================================
070        \*--------------*/
071    /**
072     *  Creates a new {@code NullErrorHandler} instance.
073     */
074    private NullErrorHandler() { /* Does nothing! */ }
075
076        /*---------*\
077    ====** Methods **==========================================================
078        \*---------*/
079    /**
080     *  {@inheritDoc}
081     */
082    @Override
083    public final void error( final SAXParseException exception ) { /* Does nothing */ }
084
085    /**
086     *  {@inheritDoc}
087     */
088    @Override
089    public final void fatalError( final SAXParseException exception ) { /* Does nothing */ }
090
091    /**
092     *  {@inheritDoc}
093     */
094    @Override
095    public final void warning( final SAXParseException exception ) { /* Does nothing */ }
096}
097//  class NullErrorHandler
098
099/*
100 *  End of File
101 */