001    /*
002     *   Copyright (c) 2009 The JOMC Project
003     *   Copyright (c) 2005 Christian Schulte <cs@jomc.org>
004     *   All rights reserved.
005     *
006     *   Redistribution and use in source and binary forms, with or without
007     *   modification, are permitted provided that the following conditions
008     *   are met:
009     *
010     *     o Redistributions of source code must retain the above copyright
011     *       notice, this list of conditions and the following disclaimer.
012     *
013     *     o Redistributions in binary form must reproduce the above copyright
014     *       notice, this list of conditions and the following disclaimer in
015     *       the documentation and/or other materials provided with the
016     *       distribution.
017     *
018     *   THIS SOFTWARE IS PROVIDED BY THE JOMC PROJECT AND CONTRIBUTORS "AS IS"
019     *   AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
020     *   THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
021     *   PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE JOMC PROJECT OR
022     *   CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
023     *   EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
024     *   PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
025     *   OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
026     *   WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
027     *   OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
028     *   ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
029     *
030     *   $Id: TrailingWhitespaceEditor.java 891 2009-11-02 03:40:00Z schulte2005 $
031     *
032     */
033    package org.jomc.util;
034    
035    /**
036     * {@code LineEditor} removing trailing whitespace.
037     *
038     * @author <a href="mailto:cs@jomc.org">Christian Schulte</a>
039     * @version $Id: TrailingWhitespaceEditor.java 891 2009-11-02 03:40:00Z schulte2005 $
040     *
041     * @see #edit(java.lang.String)
042     */
043    public final class TrailingWhitespaceEditor extends LineEditor
044    {
045    
046        /** Creates a new {@code TrailingWhitespaceEditor} instance. */
047        public TrailingWhitespaceEditor()
048        {
049            super();
050        }
051    
052        /**
053         * Creates a new {@code TrailingWhitespaceEditor} instance taking a string to use for separating lines.
054         *
055         * @param lineSeparator String to use for separating lines.
056         */
057        public TrailingWhitespaceEditor( final String lineSeparator )
058        {
059            super( lineSeparator );
060        }
061    
062        /**
063         * Creates a new {@code TrailingWhitespaceEditor} instance taking an editor to chain.
064         *
065         * @param editor The editor to chain.
066         */
067        public TrailingWhitespaceEditor( final LineEditor editor )
068        {
069            super( editor );
070        }
071    
072        /**
073         * Creates a new {@code TrailingWhitespaceEditor} instance taking an editor to chain and a string to use for separating lines.
074         *
075         * @param editor The editor to chain.
076         * @param lineSeparator String to use for separating lines.
077         */
078        public TrailingWhitespaceEditor( final LineEditor editor, final String lineSeparator )
079        {
080            super( editor, lineSeparator );
081        }
082    
083        @Override
084        protected String editLine( final String line )
085        {
086            String replacement = line;
087    
088            if ( line != null )
089            {
090                StringBuilder whitespace = null;
091                boolean sawWhitespace = false;
092                final StringBuilder buf = new StringBuilder( line.length() );
093                final char[] chars = line.toCharArray();
094    
095                for ( int i = 0; i < chars.length; i++ )
096                {
097                    if ( Character.isWhitespace( chars[i] ) )
098                    {
099                        if ( whitespace == null )
100                        {
101                            whitespace = new StringBuilder();
102                        }
103    
104                        whitespace.append( chars[i] );
105                        sawWhitespace = true;
106                    }
107                    else
108                    {
109                        if ( sawWhitespace )
110                        {
111                            buf.append( whitespace );
112                            sawWhitespace = false;
113                            whitespace = null;
114                        }
115                        buf.append( chars[i] );
116                    }
117                }
118    
119                replacement = buf.toString();
120            }
121    
122            return replacement;
123        }
124    
125    }