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 String SCHEME_FILE = "file";
37 private static final FileSystemProviders INSTALLED = new FileSystemProviders(FileSystemProvider.installedProviders());
38
39 /**
40 * Gets the {@link FileSystemProvider} for the given Path.
41 *
42 * @param path The Path to query
43 * @return the {@link FileSystemProvider} for the given Path.
44 */
45 @SuppressWarnings("resource") // FileSystem is not allocated here.
46 public static FileSystemProvider getFileSystemProvider(final Path path) {
47 return Objects.requireNonNull(path, "path").getFileSystem().provider();
48 }
49
50 /**
51 * Returns the instance for the installed providers.
52 *
53 * @return the instance for the installed providers.
54 * @see FileSystemProvider#installedProviders()
55 */
56 public static FileSystemProviders installed() {
57 return INSTALLED;
58 }
59
60 private final List<FileSystemProvider> providers;
61
62 /*
63 * Might make public later.
64 */
65 private FileSystemProviders(final List<FileSystemProvider> providers) {
66 this.providers = providers != null ? providers : Collections.emptyList();
67 }
68
69 /**
70 * Gets the {@link FileSystemProvider} for the given scheme.
71 *
72 * @param scheme The scheme to query.
73 * @return the {@link FileSystemProvider} for the given URI or null.
74 */
75 @SuppressWarnings("resource") // FileSystems.getDefault() returns a constant.
76 public FileSystemProvider getFileSystemProvider(final String scheme) {
77 Objects.requireNonNull(scheme, "scheme");
78 // Check default provider first to avoid loading of installed providers.
79 if (scheme.equalsIgnoreCase(SCHEME_FILE)) {
80 return FileSystems.getDefault().provider();
81 }
82 // Find provider.
83 return providers.stream().filter(provider -> provider.getScheme().equalsIgnoreCase(scheme)).findFirst().orElse(null);
84 }
85
86 /**
87 * Gets the {@link FileSystemProvider} for the given URI.
88 *
89 * @param uri The URI to query
90 * @return the {@link FileSystemProvider} for the given URI or null.
91 */
92 public FileSystemProvider getFileSystemProvider(final URI uri) {
93 return getFileSystemProvider(Objects.requireNonNull(uri, "uri").getScheme());
94 }
95
96 /**
97 * Gets the {@link FileSystemProvider} for the given URL.
98 *
99 * @param url The URL to query
100 * @return the {@link FileSystemProvider} for the given URI or null.
101 */
102 public FileSystemProvider getFileSystemProvider(final URL url) {
103 return getFileSystemProvider(Objects.requireNonNull(url, "url").getProtocol());
104 }
105
106 }