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 border="1" cellpadding="8" summary="Supported attributes">
45 * <tr>
46 * <th> Name </th>
47 * <th> Type </th>
48 * </tr>
49 * <tr>
50 * <td> "lastModifiedTime" </td>
51 * <td> {@link FileTime} </td>
52 * </tr>
53 * <tr>
54 * <td> "lastAccessTime" </td>
55 * <td> {@link FileTime} </td>
56 * </tr>
57 * <tr>
58 * <td> "creationTime" </td>
59 * <td> {@link FileTime} </td>
60 * </tr>
61 * <tr>
62 * <td> "size" </td>
63 * <td> {@link Long} </td>
64 * </tr>
65 * <tr>
66 * <td> "isRegularFile" </td>
67 * <td> {@link Boolean} </td>
68 * </tr>
69 * <tr>
70 * <td> "isDirectory" </td>
71 * <td> {@link Boolean} </td>
72 * </tr>
73 * <tr>
74 * <td> "isSymbolicLink" </td>
75 * <td> {@link Boolean} </td>
76 * </tr>
77 * <tr>
78 * <td> "isOther" </td>
79 * <td> {@link Boolean} </td>
80 * </tr>
81 * <tr>
82 * <td> "fileKey" </td>
83 * <td> {@link Object} </td>
84 * </tr>
85 * </table>
86 * </blockquote>
87 *
88 * <p> The {@link java.nio.file.Files#getAttribute getAttribute} method may be
89 * used to read any of these attributes as if by invoking the {@link
90 * #readAttributes() readAttributes()} method.
91 *
92 * <p> The {@link java.nio.file.Files#setAttribute setAttribute} method may be
93 * used to update the file's last modified time, last access time or create time
94 * attributes as if by invoking the {@link #setTimes setTimes} method.
95 *
96 * @since 1.7
97 */
98
99 public interface BasicFileAttributeView
100 extends FileAttributeView
101 {
102 /**
103 * Returns the name of the attribute view. Attribute views of this type
104 * have the name {@code "basic"}.
105 */
106 @Override
107 String name();
108
109 /**
110 * Reads the basic file attributes as a bulk operation.
111 *
112 * <p> It is implementation specific if all file attributes are read as an
113 * atomic operation with respect to other file system operations.
114 *
115 * @return the file attributes
116 *
117 * @throws IOException
118 * if an I/O error occurs
119 * @throws SecurityException
120 * In the case of the default provider, a security manager is
121 * installed, its {@link SecurityManager#checkRead(String) checkRead}
122 * method is invoked to check read access to the file
123 */
124 BasicFileAttributes readAttributes() throws IOException;
125
126 /**
127 * Updates any or all of the file's last modified time, last access time,
128 * and create time attributes.
129 *
130 * <p> This method updates the file's timestamp attributes. The values are
131 * converted to the epoch and precision supported by the file system.
132 * Converting from finer to coarser granularities result in precision loss.
133 * The behavior of this method when attempting to set a timestamp that is
134 * not supported or to a value that is outside the range supported by the
135 * underlying file store is not defined. It may or not fail by throwing an
136 * {@code IOException}.
137 *
138 * <p> If any of the {@code lastModifiedTime}, {@code lastAccessTime},
139 * or {@code createTime} parameters has the value {@code null} then the
140 * corresponding timestamp is not changed. An implementation may require to
141 * read the existing values of the file attributes when only some, but not
142 * all, of the timestamp attributes are updated. Consequently, this method
143 * may not be an atomic operation with respect to other file system
144 * operations. Reading and re-writing existing values may also result in
145 * precision loss. If all of the {@code lastModifiedTime}, {@code
146 * lastAccessTime} and {@code createTime} parameters are {@code null} then
147 * this method has no effect.
148 *
149 * <p> <b>Usage Example:</b>
150 * Suppose we want to change a file's last access time.
151 * <pre>
152 * Path path = ...
153 * FileTime time = ...
154 * Files.getFileAttributeView(path, BasicFileAttributeView.class).setTimes(null, time, null);
155 * </pre>
156 *
157 * @param lastModifiedTime
158 * the new last modified time, or {@code null} to not change the
159 * value
160 * @param lastAccessTime
161 * the last access time, or {@code null} to not change the value
162 * @param createTime
163 * the file's create time, or {@code null} to not change the value
164 *
165 * @throws IOException
166 * if an I/O error occurs
167 * @throws SecurityException
168 * In the case of the default provider, a security manager is
169 * installed, its {@link SecurityManager#checkWrite(String) checkWrite}
170 * method is invoked to check write access to the file
171 *
172 * @see java.nio.file.Files#setLastModifiedTime
173 */
174 void setTimes(FileTime lastModifiedTime,
175 FileTime lastAccessTime,
176 FileTime createTime) throws IOException;
177 }