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: LineEditor.java 891 2009-11-02 03:40:00Z schulte2005 $ 031 * 032 */ 033 package org.jomc.util; 034 035 import java.io.BufferedReader; 036 import java.io.IOException; 037 import java.io.StringReader; 038 039 /** 040 * Interface to line based editing. 041 * 042 * @author <a href="mailto:cs@jomc.org">Christian Schulte</a> 043 * @version $Id: LineEditor.java 891 2009-11-02 03:40:00Z schulte2005 $ 044 * 045 * @see #edit(java.lang.String) 046 */ 047 public class LineEditor 048 { 049 050 /** Editor to chain. */ 051 private LineEditor editor; 052 053 /** Line separator. */ 054 private String lineSeparator; 055 056 /** Creates a new {@code LineEditor} instance. */ 057 public LineEditor() 058 { 059 super(); 060 } 061 062 /** 063 * Creates a new {@code LineEditor} instance taking a string to use for separating lines. 064 * 065 * @param lineSeparator String to use for separating lines. 066 */ 067 public LineEditor( final String lineSeparator ) 068 { 069 super(); 070 this.lineSeparator = lineSeparator; 071 } 072 073 /** 074 * Creates a new {@code LineEditor} instance taking an editor to chain. 075 * 076 * @param editor The editor to chain. 077 */ 078 public LineEditor( final LineEditor editor ) 079 { 080 super(); 081 this.editor = editor; 082 } 083 084 /** 085 * Creates a new {@code LineEditor} instance taking an editor to chain and a string to use for separating lines. 086 * 087 * @param editor The editor to chain. 088 * @param lineSeparator String to use for separating lines. 089 */ 090 public LineEditor( final LineEditor editor, final String lineSeparator ) 091 { 092 super(); 093 this.editor = editor; 094 this.lineSeparator = lineSeparator; 095 } 096 097 /** 098 * Gets the line separator of the editor. 099 * 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 }