| 1 | /* |
| 2 | * Copyright (c) 2009 The JOMC Project |
| 3 | * Copyright (c) 2005 Christian Schulte <cs@jomc.org> |
| 4 | * All rights reserved. |
| 5 | * |
| 6 | * Redistribution and use in source and binary forms, with or without |
| 7 | * modification, are permitted provided that the following conditions |
| 8 | * are met: |
| 9 | * |
| 10 | * o Redistributions of source code must retain the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer. |
| 12 | * |
| 13 | * o Redistributions in binary form must reproduce the above copyright |
| 14 | * notice, this list of conditions and the following disclaimer in |
| 15 | * the documentation and/or other materials provided with the |
| 16 | * distribution. |
| 17 | * |
| 18 | * THIS SOFTWARE IS PROVIDED BY THE JOMC PROJECT AND CONTRIBUTORS "AS IS" |
| 19 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, |
| 20 | * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| 21 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE JOMC PROJECT OR |
| 22 | * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| 23 | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| 24 | * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; |
| 25 | * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, |
| 26 | * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR |
| 27 | * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF |
| 28 | * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 29 | * |
| 30 | * $Id: LineEditor.java 891 2009-11-02 03:40:00Z schulte2005 $ |
| 31 | * |
| 32 | */ |
| 33 | package org.jomc.util; |
| 34 | |
| 35 | import java.io.BufferedReader; |
| 36 | import java.io.IOException; |
| 37 | import java.io.StringReader; |
| 38 | |
| 39 | /** |
| 40 | * Interface to line based editing. |
| 41 | * |
| 42 | * @author <a href="mailto:cs@jomc.org">Christian Schulte</a> |
| 43 | * @version $Id: LineEditor.java 891 2009-11-02 03:40:00Z schulte2005 $ |
| 44 | * |
| 45 | * @see #edit(java.lang.String) |
| 46 | */ |
| 47 | public class LineEditor |
| 48 | { |
| 49 | |
| 50 | /** Editor to chain. */ |
| 51 | private LineEditor editor; |
| 52 | |
| 53 | /** Line separator. */ |
| 54 | private String lineSeparator; |
| 55 | |
| 56 | /** Creates a new {@code LineEditor} instance. */ |
| 57 | public LineEditor() |
| 58 | { |
| 59 | super(); |
| 60 | } |
| 61 | |
| 62 | /** |
| 63 | * Creates a new {@code LineEditor} instance taking a string to use for separating lines. |
| 64 | * |
| 65 | * @param lineSeparator String to use for separating lines. |
| 66 | */ |
| 67 | public LineEditor( final String lineSeparator ) |
| 68 | { |
| 69 | super(); |
| 70 | this.lineSeparator = lineSeparator; |
| 71 | } |
| 72 | |
| 73 | /** |
| 74 | * Creates a new {@code LineEditor} instance taking an editor to chain. |
| 75 | * |
| 76 | * @param editor The editor to chain. |
| 77 | */ |
| 78 | public LineEditor( final LineEditor editor ) |
| 79 | { |
| 80 | super(); |
| 81 | this.editor = editor; |
| 82 | } |
| 83 | |
| 84 | /** |
| 85 | * Creates a new {@code LineEditor} instance taking an editor to chain and a string to use for separating lines. |
| 86 | * |
| 87 | * @param editor The editor to chain. |
| 88 | * @param lineSeparator String to use for separating lines. |
| 89 | */ |
| 90 | public LineEditor( final LineEditor editor, final String lineSeparator ) |
| 91 | { |
| 92 | super(); |
| 93 | this.editor = editor; |
| 94 | this.lineSeparator = lineSeparator; |
| 95 | } |
| 96 | |
| 97 | /** |
| 98 | * Gets the line separator of the editor. |
| 99 | * |
| 100 | * @return The line separator of the editor. |
| 101 | */ |
| 102 | public final String getLineSeparator() |
| 103 | { |
| 104 | if ( this.lineSeparator == null ) |
| 105 | { |
| 106 | this.lineSeparator = System.getProperty( "line.separator" ); |
| 107 | } |
| 108 | |
| 109 | return this.lineSeparator; |
| 110 | } |
| 111 | |
| 112 | /** |
| 113 | * Edits text. |
| 114 | * <p>This method splits the given string into lines and passes every line to method {@code editLine} in order of |
| 115 | * occurrence. On end of input, method {@code editLine} is called with a {@code null} argument.</p> |
| 116 | * |
| 117 | * @param text The text to edit or {@code null}. |
| 118 | * |
| 119 | * @return The edited text or {@code null}. |
| 120 | * |
| 121 | * @throws IOException if editing fails. |
| 122 | */ |
| 123 | public final String edit( final String text ) throws IOException |
| 124 | { |
| 125 | String edited = text; |
| 126 | |
| 127 | if ( text != null ) |
| 128 | { |
| 129 | final BufferedReader reader = new BufferedReader( new StringReader( text ) ); |
| 130 | final StringBuilder buf = new StringBuilder(); |
| 131 | |
| 132 | String line = null; |
| 133 | while ( ( line = reader.readLine() ) != null ) |
| 134 | { |
| 135 | final String replacement = this.editLine( line ); |
| 136 | if ( replacement != null ) |
| 137 | { |
| 138 | buf.append( replacement ).append( this.getLineSeparator() ); |
| 139 | } |
| 140 | } |
| 141 | |
| 142 | final String replacement = this.editLine( null ); |
| 143 | if ( replacement != null ) |
| 144 | { |
| 145 | buf.append( replacement ); |
| 146 | } |
| 147 | |
| 148 | edited = buf.toString(); |
| 149 | |
| 150 | if ( this.editor != null ) |
| 151 | { |
| 152 | edited = this.editor.edit( edited ); |
| 153 | } |
| 154 | } |
| 155 | |
| 156 | return edited; |
| 157 | } |
| 158 | |
| 159 | /** |
| 160 | * Edits a line. |
| 161 | * |
| 162 | * @param line The line to edit or {@code null} indicating the end of input. |
| 163 | * |
| 164 | * @return The string to replace {@code line} with, or {@code null} to replace {@code line} with nothing. |
| 165 | * |
| 166 | * @throws IOException if editing fails. |
| 167 | */ |
| 168 | protected String editLine( final String line ) throws IOException |
| 169 | { |
| 170 | return line; |
| 171 | } |
| 172 | |
| 173 | } |