1 /*
2 * Copyright (c) 2011, 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 sun.nio.fs;
27
28 import java.nio.file.Path;
29 import java.nio.file.LinkOption;
30 import java.nio.file.attribute.BasicFileAttributes;
31 import java.nio.file.spi.FileSystemProvider;
32 import java.io.IOException;
33 import java.util.Map;
34
35 /**
36 * Base implementation class of FileSystemProvider
37 */
38
39 public abstract class AbstractFileSystemProvider extends FileSystemProvider {
40 protected AbstractFileSystemProvider() { }
41
42 /**
43 * Splits the given attribute name into the name of an attribute view and
44 * the attribute. If the attribute view is not identified then it assumed
45 * to be "basic".
46 */
47 private static String[] split(String attribute) {
48 String[] s = new String[2];
49 int pos = attribute.indexOf(':');
50 if (pos == -1) {
51 s[0] = "basic";
52 s[1] = attribute;
53 } else {
54 s[0] = attribute.substring(0, pos++);
55 s[1] = (pos == attribute.length()) ? "" : attribute.substring(pos);
56 }
57 return s;
58 }
59
60 /**
61 * Gets a DynamicFileAttributeView by name. Returns {@code null} if the
62 * view is not available.
63 */
64 abstract DynamicFileAttributeView getFileAttributeView(Path file,
65 String name,
66 LinkOption... options);
67
68 @Override
69 public final void setAttribute(Path file,
70 String attribute,
71 Object value,
72 LinkOption... options)
73 throws IOException
74 {
75 String[] s = split(attribute);
76 if (s[0].length() == 0)
77 throw new IllegalArgumentException(attribute);
78 DynamicFileAttributeView view = getFileAttributeView(file, s[0], options);
79 if (view == null)
80 throw new UnsupportedOperationException("View '" + s[0] + "' not available");
81 view.setAttribute(s[1], value);
82 }
83
84 @Override
85 public final Map<String,Object> readAttributes(Path file, String attributes, LinkOption... options)
86 throws IOException
87 {
88 String[] s = split(attributes);
89 if (s[0].length() == 0)
90 throw new IllegalArgumentException(attributes);
91 DynamicFileAttributeView view = getFileAttributeView(file, s[0], options);
92 if (view == null)
93 throw new UnsupportedOperationException("View '" + s[0] + "' not available");
94 return view.readAttributes(s[1].split(","));
95 }
96
97 /**
98 * Deletes a file. The {@code failIfNotExists} parameters determines if an
99 * {@code IOException} is thrown when the file does not exist.
100 */
101 abstract boolean implDelete(Path file, boolean failIfNotExists) throws IOException;
102
103 @Override
104 public final void delete(Path file) throws IOException {
105 implDelete(file, true);
106 }
107
108 @Override
109 public final boolean deleteIfExists(Path file) throws IOException {
110 return implDelete(file, false);
111 }
112
113 /**
114 * Tests whether a file is a directory.
115 *
116 * @return {@code true} if the file is a directory; {@code false} if
117 * the file does not exist, is not a directory, or it cannot
118 * be determined if the file is a directory or not.
119 */
120 public boolean isDirectory(Path file) {
121 try {
122 return readAttributes(file, BasicFileAttributes.class).isDirectory();
123 } catch (IOException ioe) {
124 return false;
125 }
126 }
127
128 /**
129 * Tests whether a file is a regular file with opaque content.
130 *
131 * @return {@code true} if the file is a regular file; {@code false} if
132 * the file does not exist, is not a regular file, or it
133 * cannot be determined if the file is a regular file or not.
134 */
135 public boolean isRegularFile(Path file) {
136 try {
137 return readAttributes(file, BasicFileAttributes.class).isRegularFile();
138 } catch (IOException ioe) {
139 return false;
140 }
141 }
142
143 /**
144 * Checks the existence of a file.
145 *
146 * @return {@code true} if the file exists; {@code false} if the file does
147 * not exist or its existence cannot be determined.
148 */
149 public boolean exists(Path file) {
150 try {
151 checkAccess(file);
152 return true;
153 } catch (IOException ioe) {
154 return false;
155 }
156 }
157 }