1 /*
2 * Copyright (c) 2009, 2016, 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 java.io.IOException;
32 import java.nio.file.attribute.FileAttribute;
33 import java.nio.file.attribute.PosixFilePermission;
34 import java.nio.file.attribute.PosixFilePermissions;
35 import static java.nio.file.attribute.PosixFilePermission.*;
36 import sun.security.action.GetPropertyAction;
37
38
39 /**
40 * Helper class to support creation of temporary files and directories with
41 * initial attributes.
42 */
43
44 class TempFileHelper {
45 private TempFileHelper() { }
46
47 // temporary directory location
48 private static final Path tmpdir =
49 Paths.get(GetPropertyAction.privilegedGetProperty("java.io.tmpdir"));
50
51 private static final boolean isPosix =
52 FileSystems.getDefault().supportedFileAttributeViews().contains("posix");
53
54 // file name generation, same as java.io.File for now
55 private static final SecureRandom random = new SecureRandom();
56 private static Path generatePath(String prefix, String suffix, Path dir) {
57 long n = random.nextLong();
58 String s = prefix + Long.toUnsignedString(n) + suffix;
59 Path name = dir.getFileSystem().getPath(s);
60 // the generated name should be a simple file name
61 if (name.getParent() != null)
62 throw new IllegalArgumentException("Invalid prefix or suffix");
63 return dir.resolve(name);
64 }
65
66 // default file and directory permissions (lazily initialized)
67 private static class PosixPermissions {
68 static final FileAttribute<Set<PosixFilePermission>> filePermissions =
69 PosixFilePermissions.asFileAttribute(EnumSet.of(OWNER_READ, OWNER_WRITE));
70 static final FileAttribute<Set<PosixFilePermission>> dirPermissions =
71 PosixFilePermissions.asFileAttribute(EnumSet
72 .of(OWNER_READ, OWNER_WRITE, OWNER_EXECUTE));
73 }
74
75 /**
76 * Creates a file or directory in the given directory (or in the
77 * temporary directory if dir is {@code null}).
78 */
79 private static Path create(Path dir,
80 String prefix,
81 String suffix,
82 boolean createDirectory,
83 FileAttribute<?>[] attrs)
84 throws IOException
85 {
86 if (prefix == null)
87 prefix = "";
88 if (suffix == null)
89 suffix = (createDirectory) ? "" : ".tmp";
90 if (dir == null)
91 dir = tmpdir;
92
93 // in POSIX environments use default file and directory permissions
94 // if initial permissions not given by caller.
95 if (isPosix && (dir.getFileSystem() == FileSystems.getDefault())) {
96 if (attrs.length == 0) {
97 // no attributes so use default permissions
98 attrs = new FileAttribute<?>[1];
99 attrs[0] = (createDirectory) ? PosixPermissions.dirPermissions :
100 PosixPermissions.filePermissions;
101 } else {
102 // check if posix permissions given; if not use default
103 boolean hasPermissions = false;
104 for (int i=0; i<attrs.length; i++) {
105 if (attrs[i].name().equals("posix:permissions")) {
106 hasPermissions = true;
107 break;
108 }
109 }
110 if (!hasPermissions) {
111 FileAttribute<?>[] copy = new FileAttribute<?>[attrs.length+1];
112 System.arraycopy(attrs, 0, copy, 0, attrs.length);
113 attrs = copy;
114 attrs[attrs.length-1] = (createDirectory) ?
115 PosixPermissions.dirPermissions :
116 PosixPermissions.filePermissions;
117 }
118 }
119 }
120
121 // loop generating random names until file or directory can be created
122 SecurityManager sm = System.getSecurityManager();
123 for (;;) {
124 Path f;
125 try {
126 f = generatePath(prefix, suffix, dir);
127 } catch (InvalidPathException e) {
128 // don't reveal temporary directory location
129 if (sm != null)
130 throw new IllegalArgumentException("Invalid prefix or suffix");
131 throw e;
132 }
133 try {
134 if (createDirectory) {
135 return Files.createDirectory(f, attrs);
136 } else {
137 return Files.createFile(f, attrs);
138 }
139 } catch (SecurityException e) {
140 // don't reveal temporary directory location
141 if (dir == tmpdir && sm != null)
142 throw new SecurityException("Unable to create temporary file or directory");
143 throw e;
144 } catch (FileAlreadyExistsException e) {
145 // ignore
146 }
147 }
148 }
149
150 /**
151 * Creates a temporary file in the given directory, or in the
152 * temporary directory if dir is {@code null}.
153 */
154 static Path createTempFile(Path dir,
155 String prefix,
156 String suffix,
157 FileAttribute<?>[] attrs)
158 throws IOException
159 {
160 return create(dir, prefix, suffix, false, attrs);
161 }
162
163 /**
164 * Creates a temporary directory in the given directory, or in the
165 * temporary directory if dir is {@code null}.
166 */
167 static Path createTempDirectory(Path dir,
168 String prefix,
169 FileAttribute<?>[] attrs)
170 throws IOException
171 {
172 return create(dir, prefix, null, true, attrs);
173 }
174 }