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 package org.apache.commons.vfs2;
18
19 import java.lang.reflect.InvocationTargetException;
20 import java.lang.reflect.Method;
21
22 import org.apache.commons.lang3.reflect.MethodUtils;
23 import org.apache.commons.vfs2.provider.AbstractFileSystem;
24
25 /**
26 * The main entry point for the VFS. Used to create {@link FileSystemManager} instances.
27 */
28 public final class VFS {
29
30 /** The FileSystemManager */
31 private static FileSystemManager instance;
32
33 /** The URI style */
34 private static Boolean uriStyle;
35
36 /**
37 * Closes the default {@link FileSystemManager} instance.
38 * <p>
39 * Warning, if you close the default instance, a new one will be created by {@link #getManager()}.
40 * </p>
41 *
42 * @since 2.8.0
43 */
44 public static synchronized void close() {
45 if (instance != null) {
46 instance.close();
47 instance = null;
48 }
49 }
50
51 /**
52 * Creates a file system manager instance.
53 *
54 * @param managerClassName The specific manager implementation class name.
55 * @return The FileSystemManager.
56 * @throws FileSystemException if an error occurs creating the manager.
57 */
58 private static FileSystemManager createFileSystemManager(final String managerClassName) throws FileSystemException {
59 try {
60 // Create instance
61 final Class<FileSystemManager> clazz = (Class<FileSystemManager>) Class.forName(managerClassName);
62 final FileSystemManager manager = clazz.getConstructor().newInstance();
63 // Initialize
64 if (manager instanceof AbstractFileSystem) {
65 ((AbstractFileSystem) manager).init();
66 } else {
67 final Method method = MethodUtils.getMatchingMethod(clazz, "init");
68 if (method != null) {
69 method.invoke(manager, (Object[]) null);
70 }
71 }
72 return manager;
73 } catch (final InvocationTargetException e) {
74 throw new FileSystemException("vfs/create-manager.error", managerClassName, e.getTargetException());
75 } catch (final Exception e) {
76 throw new FileSystemException("vfs/create-manager.error", managerClassName, e);
77 }
78 }
79
80 /**
81 * Gets the default {@link FileSystemManager} instance.
82 * <p>
83 * Warning, if you close this instance you may affect all current and future users of this manager singleton.
84 * </p>
85 *
86 * @return The FileSystemManager.
87 * @throws FileSystemException if an error occurs creating the manager.
88 */
89 public static synchronized FileSystemManager getManager() throws FileSystemException {
90 if (instance == null) {
91 instance = reset();
92 }
93 return instance;
94 }
95
96 /**
97 * TODO.
98 *
99 * @return TODO.
100 */
101 public static boolean isUriStyle() {
102 if (uriStyle == null) {
103 uriStyle = Boolean.FALSE;
104 }
105 return uriStyle.booleanValue();
106 }
107
108 /**
109 * Resets the FileSystemManager to the default.
110 *
111 * @return the new FileSystemManager.
112 * @throws FileSystemException if an error occurs creating the manager.
113 * @since 2.5.0
114 */
115 public static synchronized FileSystemManager reset() throws FileSystemException {
116 close();
117 return instance = createFileSystemManager("org.apache.commons.vfs2.impl.StandardFileSystemManager");
118 }
119
120 /**
121 * Sets the file system manager.
122 *
123 * @param manager the file system manager
124 * @since 2.2
125 */
126 public static synchronized void setManager(final FileSystemManager manager) {
127 instance = manager;
128 }
129
130 /**
131 * TODO.
132 *
133 * @param uriStyle TODO.
134 */
135 public static void setUriStyle(final boolean uriStyle) {
136 if (VFS.uriStyle != null && VFS.uriStyle.booleanValue() != uriStyle) {
137 throw new IllegalStateException("VFS.uriStyle was already set differently.");
138 }
139 VFS.uriStyle = Boolean.valueOf(uriStyle);
140 }
141
142 private VFS() {
143 // no public instantiation.
144 }
145 }