001/*
002 * ============================================================================
003 * Copyright © 2002-2023 by Thomas Thrien.
004 * All Rights Reserved.
005 * ============================================================================
006 *
007 * Licensed to the public under the agreements of the GNU Lesser General Public
008 * License, version 3.0 (the "License"). You may obtain a copy of the License at
009 *
010 *      http://www.gnu.org/licenses/lgpl.html
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
014 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
015 * License for the specific language governing permissions and limitations
016 * under the License.
017 */
018
019package org.tquadrat.foundation.util.stringconverter;
020
021import static java.lang.String.format;
022import static org.apiguardian.api.API.Status.STABLE;
023import static org.tquadrat.foundation.lang.Objects.isNull;
024import static org.tquadrat.foundation.lang.Objects.nonNull;
025import static org.tquadrat.foundation.util.StringUtils.isEmpty;
026
027import java.io.File;
028import java.io.Serial;
029
030import org.apiguardian.api.API;
031import org.tquadrat.foundation.annotation.ClassVersion;
032import org.tquadrat.foundation.lang.StringConverter;
033
034/**
035 *  An implementation of
036 *  {@link StringConverter}
037 *  for
038 *  {@link File}
039 *  values.<br>
040 *  <br>The file or folder that will be identified by the respective
041 *  {@code File} object do not need to exist nor is it guaranteed that it can
042 *  be accessed or create through the current user.<br>
043 *  <br>File names will not be normalised or canonicalized.<br>
044 *  <br>A file name of only blanks will be accepted as valid, while the empty
045 *  String will cause an
046 *  {@link IllegalArgumentException}.
047 *
048 *  @extauthor Thomas Thrien - thomas.thrien@tquadrat.org
049 *  @version $Id: FileStringConverter.java 1060 2023-09-24 19:21:40Z tquadrat $
050 *  @since 0.0.6
051 *
052 *  @UMLGraph.link
053 */
054@ClassVersion( sourceVersion = "$Id: FileStringConverter.java 1060 2023-09-24 19:21:40Z tquadrat $" )
055@API( status = STABLE, since = "0.0.6" )
056public final class FileStringConverter implements StringConverter<File>
057{
058        /*-----------*\
059    ====** Constants **========================================================
060        \*-----------*/
061    /**
062     *  The error message for an invalid file name {@value}.
063     */
064    public static final String MSG_InvalidFileName = "'%s' cannot be parsed as a valid file name";
065
066        /*------------------------*\
067    ====** Static Initialisations **===========================================
068        \*------------------------*/
069    /**
070     *  The serial version UID for objects of this class: {@value}.
071     *
072     *  @hidden
073     */
074    @Serial
075    private static final long serialVersionUID = 1L;
076
077    /**
078     *  An instance of this class.
079     */
080    public static final FileStringConverter INSTANCE = new FileStringConverter();
081
082        /*--------------*\
083    ====** Constructors **=====================================================
084        \*--------------*/
085    /**
086     *  Creates a new instance of {@code FileStringConverter}.
087     */
088    public FileStringConverter() {}
089
090        /*---------*\
091    ====** Methods **==========================================================
092        \*---------*/
093    /**
094     *  {@inheritDoc}
095     */
096    @Override
097    public final File fromString( final CharSequence source ) throws IllegalArgumentException
098    {
099        File retValue = null;
100        if( nonNull( source ) )
101        {
102            if( isEmpty( source ) ) throw new IllegalArgumentException( format( MSG_InvalidFileName, source ) );
103            retValue = new File( source.toString() );
104        }
105
106        //---* Done *----------------------------------------------------------
107        return retValue;
108    }   //  fromString()
109
110    /**
111     *  This method is used by the
112     *  {@link java.util.ServiceLoader}
113     *  to obtain the instance for this
114     *  {@link org.tquadrat.foundation.lang.StringConverter}
115     *  implementation.
116     *
117     *  @return The instance for this {@code StringConverter} implementation.
118     */
119    public static final FileStringConverter provider() { return INSTANCE; }
120
121    /**
122     *  {@inheritDoc}
123     */
124    @Override
125    public final String toString( final File source )
126    {
127        final var retValue = isNull( source ) ? null : source.getPath();
128
129        //---* Done *----------------------------------------------------------
130        return retValue;
131    }   //  toString()
132}
133//  class FileStringConverter
134
135/*
136 *  End of File
137 */