1 /*
2 * Copyright (c) 2007, 2013, 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.attribute;
27
28 import java.io.IOException;
29
30 /**
31 * A file attribute view that provides a view of a <em>basic set</em> of file
32 * attributes common to many file systems. The basic set of file attributes
33 * consist of <em>mandatory</em> and <em>optional</em> file attributes as
34 * defined by the {@link BasicFileAttributes} interface.
35
36 * <p> The file attributes are retrieved from the file system as a <em>bulk
37 * operation</em> by invoking the {@link #readAttributes() readAttributes} method.
38 * This class also defines the {@link #setTimes setTimes} method to update the
39 * file's time attributes.
40 *
41 * <p> Where dynamic access to file attributes is required, the attributes
42 * supported by this attribute view have the following names and types:
43 * <blockquote>
44 * <table class="striped">
45 * <caption style="display:none">Supported attributes</caption>
46 * <thead>
47 * <tr>
48 * <th> Name </th>
49 * <th> Type </th>
50 * </tr>
51 * </thead>
52 * <tbody>
53 * <tr>
54 * <td> "lastModifiedTime" </td>
55 * <td> {@link FileTime} </td>
56 * </tr>
57 * <tr>
58 * <td> "lastAccessTime" </td>
59 * <td> {@link FileTime} </td>
60 * </tr>
61 * <tr>
62 * <td> "creationTime" </td>
63 * <td> {@link FileTime} </td>
64 * </tr>
65 * <tr>
66 * <td> "size" </td>
67 * <td> {@link Long} </td>
68 * </tr>
69 * <tr>
70 * <td> "isRegularFile" </td>
71 * <td> {@link Boolean} </td>
72 * </tr>
73 * <tr>
74 * <td> "isDirectory" </td>
75 * <td> {@link Boolean} </td>
76 * </tr>
77 * <tr>
78 * <td> "isSymbolicLink" </td>
79 * <td> {@link Boolean} </td>
80 * </tr>
81 * <tr>
82 * <td> "isOther" </td>
83 * <td> {@link Boolean} </td>
84 * </tr>
85 * <tr>
86 * <td> "fileKey" </td>
87 * <td> {@link Object} </td>
88 * </tr>
89 * </tbody>
90 * </table>
91 * </blockquote>
92 *
93 * <p> The {@link java.nio.file.Files#getAttribute getAttribute} method may be
94 * used to read any of these attributes as if by invoking the {@link
95 * #readAttributes() readAttributes()} method.
96 *
97 * <p> The {@link java.nio.file.Files#setAttribute setAttribute} method may be
98 * used to update the file's last modified time, last access time or create time
99 * attributes as if by invoking the {@link #setTimes setTimes} method.
100 *
101 * @since 1.7
102 */
103
104 public interface BasicFileAttributeView
105 extends FileAttributeView
106 {
107 /**
108 * Returns the name of the attribute view. Attribute views of this type
109 * have the name {@code "basic"}.
110 */
111 @Override
112 String name();
113
114 /**
115 * Reads the basic file attributes as a bulk operation.
116 *
117 * <p> It is implementation specific if all file attributes are read as an
118 * atomic operation with respect to other file system operations.
119 *
120 * @return the file attributes
121 *
122 * @throws IOException
123 * if an I/O error occurs
124 * @throws SecurityException
125 * In the case of the default provider, a security manager is
126 * installed, its {@link SecurityManager#checkRead(String) checkRead}
127 * method is invoked to check read access to the file
128 */
129 BasicFileAttributes readAttributes() throws IOException;
130
131 /**
132 * Updates any or all of the file's last modified time, last access time,
133 * and create time attributes.
134 *
135 * <p> This method updates the file's timestamp attributes. The values are
136 * converted to the epoch and precision supported by the file system.
137 * Converting from finer to coarser granularities result in precision loss.
138 * The behavior of this method when attempting to set a timestamp that is
139 * not supported or to a value that is outside the range supported by the
140 * underlying file store is not defined. It may or not fail by throwing an
141 * {@code IOException}.
142 *
143 * <p> If any of the {@code lastModifiedTime}, {@code lastAccessTime},
144 * or {@code createTime} parameters has the value {@code null} then the
145 * corresponding timestamp is not changed. An implementation may require to
146 * read the existing values of the file attributes when only some, but not
147 * all, of the timestamp attributes are updated. Consequently, this method
148 * may not be an atomic operation with respect to other file system
149 * operations. Reading and re-writing existing values may also result in
150 * precision loss. If all of the {@code lastModifiedTime}, {@code
151 * lastAccessTime} and {@code createTime} parameters are {@code null} then
152 * this method has no effect.
153 *
154 * <p> <b>Usage Example:</b>
155 * Suppose we want to change a file's last access time.
156 * <pre>
157 * Path path = ...
158 * FileTime time = ...
159 * Files.getFileAttributeView(path, BasicFileAttributeView.class).setTimes(null, time, null);
160 * </pre>
161 *
162 * @param lastModifiedTime
163 * the new last modified time, or {@code null} to not change the
164 * value
165 * @param lastAccessTime
166 * the last access time, or {@code null} to not change the value
167 * @param createTime
168 * the file's create time, or {@code null} to not change the value
169 *
170 * @throws IOException
171 * if an I/O error occurs
172 * @throws SecurityException
173 * In the case of the default provider, a security manager is
174 * installed, its {@link SecurityManager#checkWrite(String) checkWrite}
175 * method is invoked to check write access to the file
176 *
177 * @see java.nio.file.Files#setLastModifiedTime
178 */
179 void setTimes(FileTime lastModifiedTime,
180 FileTime lastAccessTime,
181 FileTime createTime) throws IOException;
182 }