1 //******************************************************************************
2 //
3 // File: Files.java
4 // Package: edu.rit.io
5 // Unit: Class edu.rit.io.Files
6 //
7 // This Java source file is copyright (C) 2007 by Alan Kaminsky. All rights
8 // reserved. For further information, contact the author, Alan Kaminsky, at
9 // ark@cs.rit.edu.
10 //
11 // This Java source file is part of the Parallel Java Library ("PJ"). PJ is free
12 // software; you can redistribute it and/or modify it under the terms of the GNU
13 // General Public License as published by the Free Software Foundation; either
14 // version 3 of the License, or (at your option) any later version.
15 //
16 // PJ is distributed in the hope that it will be useful, but WITHOUT ANY
17 // WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
18 // A PARTICULAR PURPOSE. See the GNU General Public License for more details.
19 //
20 // Linking this library statically or dynamically with other modules is making a
21 // combined work based on this library. Thus, the terms and conditions of the GNU
22 // General Public License cover the whole combination.
23 //
24 // As a special exception, the copyright holders of this library give you
25 // permission to link this library with independent modules to produce an
26 // executable, regardless of the license terms of these independent modules, and
27 // to copy and distribute the resulting executable under terms of your choice,
28 // provided that you also meet, for each linked independent module, the terms
29 // and conditions of the license of that module. An independent module is a module
30 // which is not derived from or based on this library. If you modify this library,
31 // you may extend this exception to your version of the library, but you are not
32 // obligated to do so. If you do not wish to do so, delete this exception
33 // statement from your version.
34 //
35 // A copy of the GNU General Public License is provided in the file gpl.txt. You
36 // may also obtain a copy of the GNU General Public License on the World Wide
37 // Web at http://www.gnu.org/licenses/gpl.html.
38 //
39 //******************************************************************************
40 package edu.rit.io;
41
42 import java.io.File;
43
44 /**
45 * Class Files provides static methods for various file related operations.
46 *
47 * @author Alan Kaminsky
48 * @version 26-Nov-2007
49 */
50 public class Files {
51
52 // Prevent construction.
53 private Files() {
54 }
55
56 // Exported operations.
57 /**
58 * Append the given rank to the given file. The rank goes before the file
59 * extension if any. For example,
60 * <code>Files.fileForRank(new File("image.pjg"),2)</code> returns a File
61 * whose name is <code>"image_2.pjg"</code>;
62 * <code>Files.fileForRank(new File("image"),2)</code> returns a File whose
63 * name is <code>"image_2"</code>.
64 *
65 * @param file File.
66 * @param rank Rank.
67 * @return File with rank appended.
68 */
69 public static File fileForRank(File file,
70 int rank) {
71 return fileAppend(file, "_" + rank);
72 }
73
74 /**
75 * Append the given rank to the given file name. The rank goes before the
76 * file extension if any. For example,
77 * <code>Files.fileNameForRank("image.pjg",2)</code> returns
78 * <code>"image_2.pjg"</code>; <code>Files.fileNameForRank("image",2)</code> returns
79 * <code>"image_2"</code>.
80 *
81 * @param filename File name.
82 * @param rank Rank.
83 * @return File name with rank appended.
84 */
85 public static String fileNameForRank(String filename,
86 int rank) {
87 return fileNameAppend(filename, "_" + rank);
88 }
89
90 /**
91 * Append the given suffix to the given file. The suffix goes before the
92 * file extension if any. For example,
93 * <code>Files.fileAppend(new File("image.pjg"),"_new")</code> returns a
94 * File whose name is <code>"image_new.pjg"</code>;
95 * <code>Files.fileAppend(new File("image"),"_new")</code> returns a File
96 * whose name is <code>"image_new"</code>.
97 *
98 * @param file File.
99 * @param suffix Suffix.
100 * @return File with suffix appended.
101 */
102 public static File fileAppend(File file,
103 String suffix) {
104 return new File(fileNameAppend(file.getPath(), suffix));
105 }
106
107 /**
108 * Append the given suffix to the given file name. The suffix goes before
109 * the file extension if any. For example,
110 * <code>Files.fileNameAppend("image.pjg","_new")</code> returns
111 * <code>"image_new.pjg"</code>; <code>Files.fileNameAppend("image","_new")</code>
112 * returns <code>"image_new"</code>.
113 *
114 * @param filename File name.
115 * @param suffix Suffix.
116 * @return File name with suffix appended.
117 */
118 public static String fileNameAppend(String filename,
119 String suffix) {
120 int i = filename.lastIndexOf('.');
121 return i == -1
122 ? filename + suffix
123 : filename.substring(0, i) + suffix + filename.substring(i);
124 }
125
126 /**
127 * Prepend the given prefix to the given file. The prefix goes after the
128 * directory if any. For example,
129 * <code>Files.filePrepend(new File("/home/ark/image.pjg"),"new_")</code>
130 * returns a File whose name is <code>"/home/ark/new_image.pjg"</code>;
131 * <code>Files.filePrepend(new File("image.pjg"),"new_")</code> returns a
132 * File whose name is <code>"new_image.pjg"</code>. The system-dependent file
133 * name separator character is used to detect the end of the directory if
134 * any.
135 *
136 * @param file File.
137 * @param prefix Prefix.
138 * @return File with prefix prepended.
139 */
140 public static File filePrepend(File file,
141 String prefix) {
142 return new File(fileNamePrepend(file.getPath(), prefix));
143 }
144
145 /**
146 * Prepend the given prefix to the given file name. The prefix goes after
147 * the directory if any. For example,
148 * <code>Files.fileNamePrepend("/home/ark/image.pjg","new_")</code> returns
149 * <code>"/home/ark/new_image.pjg"</code>;
150 * <code>Files.fileNamePrepend("image.pjg","new_")</code> returns
151 * <code>"new_image.pjg"</code>. The system-dependent file name separator
152 * character is used to detect the end of the directory if any.
153 *
154 * @param filename File name.
155 * @param prefix Prefix.
156 * @return File name with prefix prepended.
157 */
158 public static String fileNamePrepend(String filename,
159 String prefix) {
160 int i = filename.lastIndexOf(File.separatorChar);
161 return i == -1
162 ? prefix + filename
163 : filename.substring(0, i + 1) + prefix + filename.substring(i + 1);
164 }
165
166 // Unit test main program.
167 // /**
168 // * Unit test main program.
169 // * <P>
170 // * Usage: java edu.rit.io.Files <I>filename</I> <I>rank</I>
171 // */
172 // public static void main
173 // (String[] args)
174 // throws Exception
175 // {
176 // String filename = args[0];
177 // int rank = Integer.parseInt (args[1]);
178 // File file = new File (filename);
179 // System.out.println
180 // ("Files.fileForRank (file, rank) = " +
181 // Files.fileForRank (file, rank));
182 // System.out.println
183 // ("Files.fileNameForRank (filename, rank) = " +
184 // Files.fileNameForRank (filename, rank));
185 // }
186 // /**
187 // * Unit test main program.
188 // * <P>
189 // * Usage: java edu.rit.io.Files <I>filename</I> <I>str</I>
190 // */
191 // public static void main
192 // (String[] args)
193 // throws Exception
194 // {
195 // String filename = args[0];
196 // String str = args[1];
197 // File file = new File (filename);
198 // System.out.println
199 // ("Files.fileAppend (file, str) = " +
200 // Files.fileAppend (file, str));
201 // System.out.println
202 // ("Files.fileNameAppend (filename, str) = " +
203 // Files.fileNameAppend (filename, str));
204 // System.out.println
205 // ("Files.filePrepend (file, str) = " +
206 // Files.filePrepend (file, str));
207 // System.out.println
208 // ("Files.fileNamePrepend (filename, str) = " +
209 // Files.fileNamePrepend (filename, str));
210 // }
211 }