1 /*
2 * Copyright (c) 2009, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.nio.file;
27
28 import java.util.Set;
29 import java.util.EnumSet;
30 import java.security.SecureRandom;
31 import static java.security.AccessController.*;
32 import java.io.IOException;
33 import java.nio.file.attribute.FileAttribute;
34 import java.nio.file.attribute.PosixFilePermission;
35 import java.nio.file.attribute.PosixFilePermissions;
36 import static java.nio.file.attribute.PosixFilePermission.*;
37 import sun.security.action.GetPropertyAction;
38
39
40 /**
41 * Helper class to support creation of temporary files and directories with
42 * initial attributes.
43 */
44
45 class TempFileHelper {
46 private TempFileHelper() { }
47
48 // temporary directory location
49 private static final Path tmpdir =
50 Paths.get(doPrivileged(new GetPropertyAction("java.io.tmpdir")));
51
52 private static final boolean isPosix =
53 FileSystems.getDefault().supportedFileAttributeViews().contains("posix");
54
55 // file name generation, same as java.io.File for now
56 private static final SecureRandom random = new SecureRandom();
57 private static Path generatePath(String prefix, String suffix, Path dir) {
58 long n = random.nextLong();
59 n = (n == Long.MIN_VALUE) ? 0 : Math.abs(n);
60 Path name = dir.getFileSystem().getPath(prefix + Long.toString(n) + suffix);
61 // the generated name should be a simple file name
62 if (name.getParent() != null)
63 throw new IllegalArgumentException("Invalid prefix or suffix");
64 return dir.resolve(name);
65 }
66
67 // default file and directory permissions (lazily initialized)
68 private static class PosixPermissions {
69 static final FileAttribute<Set<PosixFilePermission>> filePermissions =
70 PosixFilePermissions.asFileAttribute(EnumSet.of(OWNER_READ, OWNER_WRITE));
71 static final FileAttribute<Set<PosixFilePermission>> dirPermissions =
72 PosixFilePermissions.asFileAttribute(EnumSet
73 .of(OWNER_READ, OWNER_WRITE, OWNER_EXECUTE));
74 }
75
76 /**
77 * Creates a file or directory in in the given given directory (or in the
78 * temporary directory if dir is {@code null}).
79 */
80 private static Path create(Path dir,
81 String prefix,
82 String suffix,
83 boolean createDirectory,
84 FileAttribute[] attrs)
85 throws IOException
86 {
87 if (prefix == null)
88 prefix = "";
89 if (suffix == null)
90 suffix = (createDirectory) ? "" : ".tmp";
91 if (dir == null)
92 dir = tmpdir;
93
94 // in POSIX environments use default file and directory permissions
95 // if initial permissions not given by caller.
96 if (isPosix && (dir.getFileSystem() == FileSystems.getDefault())) {
97 if (attrs.length == 0) {
98 // no attributes so use default permissions
99 attrs = new FileAttribute<?>[1];
100 attrs[0] = (createDirectory) ? PosixPermissions.dirPermissions :
101 PosixPermissions.filePermissions;
102 } else {
103 // check if posix permissions given; if not use default
104 boolean hasPermissions = false;
105 for (int i=0; i<attrs.length; i++) {
106 if (attrs[i].name().equals("posix:permissions")) {
107 hasPermissions = true;
108 break;
109 }
110 }
111 if (!hasPermissions) {
112 FileAttribute<?>[] copy = new FileAttribute<?>[attrs.length+1];
113 System.arraycopy(attrs, 0, copy, 0, attrs.length);
114 attrs = copy;
115 attrs[attrs.length-1] = (createDirectory) ?
116 PosixPermissions.dirPermissions :
117 PosixPermissions.filePermissions;
118 }
119 }
120 }
121
122 // loop generating random names until file or directory can be created
123 SecurityManager sm = System.getSecurityManager();
124 for (;;) {
125 Path f;
126 try {
127 f = generatePath(prefix, suffix, dir);
128 } catch (InvalidPathException e) {
129 // don't reveal temporary directory location
130 if (sm != null)
131 throw new IllegalArgumentException("Invalid prefix or suffix");
132 throw e;
133 }
134 try {
135 if (createDirectory) {
136 return Files.createDirectory(f, attrs);
137 } else {
138 return Files.createFile(f, attrs);
139 }
140 } catch (SecurityException e) {
141 // don't reveal temporary directory location
142 if (dir == tmpdir && sm != null)
143 throw new SecurityException("Unable to create temporary file or directory");
144 throw e;
145 } catch (FileAlreadyExistsException e) {
146 // ignore
147 }
148 }
149 }
150
151 /**
152 * Creates a temporary file in the given directory, or in in the
153 * temporary directory if dir is {@code null}.
154 */
155 static Path createTempFile(Path dir,
156 String prefix,
157 String suffix,
158 FileAttribute[] attrs)
159 throws IOException
160 {
161 return create(dir, prefix, suffix, false, attrs);
162 }
163
164 /**
165 * Creates a temporary directory in the given directory, or in in the
166 * temporary directory if dir is {@code null}.
167 */
168 static Path createTempDirectory(Path dir,
169 String prefix,
170 FileAttribute[] attrs)
171 throws IOException
172 {
173 return create(dir, prefix, null, true, attrs);
174 }
175 }