1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18 package org.apache.commons.io.file.spi;
19
20 import java.net.URI;
21 import java.net.URL;
22 import java.nio.file.FileSystems;
23 import java.nio.file.Path;
24 import java.nio.file.spi.FileSystemProvider;
25 import java.util.Collections;
26 import java.util.List;
27 import java.util.Objects;
28
29 /**
30 * Helps to work with {@link FileSystemProvider}.
31 *
32 * @since 2.9.0
33 */
34 public class FileSystemProviders { // NOPMD Class will be final in 3.0.
35
36 private static final FileSystemProviders INSTALLED = new FileSystemProviders(FileSystemProvider.installedProviders());
37
38 /**
39 * Gets the {@link FileSystemProvider} for the given Path.
40 *
41 * @param path The Path to query
42 * @return the {@link FileSystemProvider} for the given Path.
43 */
44 @SuppressWarnings("resource") // FileSystem is not allocated here.
45 public static FileSystemProvider getFileSystemProvider(final Path path) {
46 return Objects.requireNonNull(path, "path").getFileSystem().provider();
47 }
48
49 /**
50 * Returns the instance for the installed providers.
51 *
52 * @return the instance for the installed providers.
53 * @see FileSystemProvider#installedProviders()
54 */
55 public static FileSystemProviders installed() {
56 return INSTALLED;
57 }
58
59 private final List<FileSystemProvider> providers;
60
61 /*
62 * Might make public later.
63 */
64 private FileSystemProviders(final List<FileSystemProvider> providers) {
65 this.providers = providers != null ? providers : Collections.emptyList();
66 }
67
68 /**
69 * Gets the {@link FileSystemProvider} for the given scheme.
70 *
71 * @param scheme The scheme to query.
72 * @return the {@link FileSystemProvider} for the given URI or null.
73 */
74 @SuppressWarnings("resource") // FileSystems.getDefault() returns a constant.
75 public FileSystemProvider getFileSystemProvider(final String scheme) {
76 Objects.requireNonNull(scheme, "scheme");
77 // Check default provider first to avoid loading of installed providers.
78 if (scheme.equalsIgnoreCase("file")) {
79 return FileSystems.getDefault().provider();
80 }
81 // Find provider.
82 return providers.stream().filter(provider -> provider.getScheme().equalsIgnoreCase(scheme)).findFirst().orElse(null);
83 }
84
85 /**
86 * Gets the {@link FileSystemProvider} for the given URI.
87 *
88 * @param uri The URI to query
89 * @return the {@link FileSystemProvider} for the given URI or null.
90 */
91 public FileSystemProvider getFileSystemProvider(final URI uri) {
92 return getFileSystemProvider(Objects.requireNonNull(uri, "uri").getScheme());
93 }
94
95 /**
96 * Gets the {@link FileSystemProvider} for the given URL.
97 *
98 * @param url The URL to query
99 * @return the {@link FileSystemProvider} for the given URI or null.
100 */
101 public FileSystemProvider getFileSystemProvider(final URL url) {
102 return getFileSystemProvider(Objects.requireNonNull(url, "url").getProtocol());
103 }
104
105 }