1 /*
2 * $Source: /usr/cvsroot/melati/melati/src/main/java/org/melati/util/FileUtils.java,v $
3 * $Revision: 1.9 $
4 *
5 * Copyright (C) 2000 Myles Chippendale
6 *
7 * Part of Melati (http://melati.org), a framework for the rapid
8 * development of clean, maintainable web applications.
9 *
10 * Melati is free software; Permission is granted to copy, distribute
11 * and/or modify this software under the terms either:
12 *
13 * a) the GNU General Public License as published by the Free Software
14 * Foundation; either version 2 of the License, or (at your option)
15 * any later version,
16 *
17 * or
18 *
19 * b) any version of the Melati Software License, as published
20 * at http://melati.org
21 *
22 * You should have received a copy of the GNU General Public License and
23 * the Melati Software License along with this program;
24 * if not, write to the Free Software Foundation, Inc.,
25 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA to obtain the
26 * GNU General Public License and visit http://melati.org to obtain the
27 * Melati Software License.
28 *
29 * Feel free to contact the Developers of Melati (http://melati.org),
30 * if you would like to work out a different arrangement than the options
31 * outlined here. It is our intention to allow Melati to be used by as
32 * wide an audience as possible.
33 *
34 * This program is distributed in the hope that it will be useful,
35 * but WITHOUT ANY WARRANTY; without even the implied warranty of
36 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
37 * GNU General Public License for more details.
38 *
39 * Contact details for copyright holder:
40 *
41 * Myles Chippendale <mylesc At paneris.org>
42 * http://paneris.org/
43 * 29 Stanley Road, Oxford, OX4 1QY, UK
44 */
45
46 package org.melati.util;
47
48 import java.io.IOException;
49 import java.io.File;
50 import java.io.FileOutputStream;
51
52 /**
53 * An assortment of useful operations on <code>File</code>s.
54 */
55 public final class FileUtils {
56
57 private FileUtils() {}
58
59 /**
60 * Returns a File in the given <code>directory</code> which does
61 * not already exist.
62 *
63 * This file is found by starting with the given
64 * <code>filename</code>. If a file of this name already exists we
65 * put 0 then 1,2,... before the extension until we find one that
66 * does not exists.
67 * <p>
68 * For instance, if <code>newfile.txt</code> exists then we
69 * check <code>newfile0.txt</code>, <code>newfile1.txt</code>, ...
70 * until we find a new filename.
71 *
72 * @return a new File whose name has been made unique
73 */
74
75 public static File withUniqueName(File file) {
76 String directory = file.getParent();
77 String filename = file.getName();
78 int dot = filename.lastIndexOf(".");
79 String start = (dot != -1) ? filename.substring(0,dot) : filename;
80 String extension =
81 (dot != -1) ? filename.substring(dot,filename.length()) : "";
82
83 int count = 0;
84 while (file.exists()) {
85 filename = start + (count++) + extension;
86 file = new File(directory, filename);
87 }
88 return file;
89 }
90
91 /**
92 * Write a byte array to a given file.
93 * @param file file to write to
94 * @param data to write to file
95 * @return File with data written to it
96 */
97 public static File writeFile(File file, byte[] data) throws IOException {
98 FileOutputStream os=new FileOutputStream(file);
99 os.write(data);
100 os.close();
101 return file;
102 }
103
104 /**
105 * Mark a file as executable. Does <TT>chmod +x <I>file</I></TT> on
106 * Unix, else does nothing.
107 */
108 public static void makeExecutable(File file) throws IOException {
109 if (File.separatorChar == '/')
110 // we're unix
111 try {
112 if (Runtime.getRuntime().exec(
113 new String[] { "chmod", "+x", file.getPath() }).waitFor() != 0)
114 throw new IOException("chmod +x " + file + " failed");
115 }
116 catch (InterruptedException e) {
117 throw new IOException("Interrupted waiting for chmod +x " + file);
118 }
119 }
120 }