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.configuration2.io;
18
19 import java.io.File;
20 import java.io.InputStream;
21 import java.io.OutputStream;
22 import java.net.MalformedURLException;
23 import java.net.URL;
24
25 import org.apache.commons.configuration2.ex.ConfigurationException;
26
27 /**
28 * Abstract layer to allow various types of file systems.
29 *
30 * @since 1.7
31 */
32 public abstract class FileSystem {
33 /** Constant for the default logger. */
34 private static final ConfigurationLogger DEFAULT_LOG = ConfigurationLogger.newDummyLogger();
35
36 /** The Logger. */
37 private volatile ConfigurationLogger log;
38
39 /** FileSystem options provider. */
40 private volatile FileOptionsProvider optionsProvider;
41
42 /**
43 * Gets the base path of the given path, for example a directory for a file.
44 *
45 * @param path the source path.
46 * @return the base path.
47 */
48 public abstract String getBasePath(String path);
49
50 /**
51 * Gets the file name of the given path.
52 *
53 * @param path the source path.
54 * @return the file name.
55 */
56 public abstract String getFileName(String path);
57
58 /**
59 * Gets the FileSystem options provider.
60 *
61 * @return the FileSystem options provider.
62 */
63 public FileOptionsProvider getFileOptionsProvider() {
64 return this.optionsProvider;
65 }
66
67 /**
68 * Gets an input stream for a URL.
69 *
70 * @param url the source URL.
71 * @return an input stream.
72 * @throws ConfigurationException if an problem occurs getting the input stream.
73 */
74 public abstract InputStream getInputStream(URL url) throws ConfigurationException;
75
76 /**
77 * Not abstract for binary compatibility.
78 *
79 * @param url TODO
80 * @param urlConnectionOptions Ignored.
81 * @return TODO
82 * @throws ConfigurationException TODO
83 * @since 2.8.0
84 */
85 public InputStream getInputStream(final URL url, final URLConnectionOptions urlConnectionOptions) throws ConfigurationException {
86 return getInputStream(url);
87 }
88
89 /**
90 * Gets the logger used by this FileSystem.
91 *
92 * @return the logger
93 */
94 public ConfigurationLogger getLogger() {
95 final ConfigurationLogger result = log;
96 return result != null ? result : DEFAULT_LOG;
97 }
98
99 /**
100 * Gets an output stream for a File.
101 *
102 * @param file the source File.
103 * @return an output stream.
104 * @throws ConfigurationException if an problem occurs getting the output stream.
105 */
106 public abstract OutputStream getOutputStream(File file) throws ConfigurationException;
107
108 /**
109 * Gets an output stream for a URL.
110 *
111 * @param url the source URL.
112 * @return an output stream.
113 * @throws ConfigurationException if an problem occurs getting the output stream.
114 */
115 public abstract OutputStream getOutputStream(URL url) throws ConfigurationException;
116
117 /**
118 * Gets a path string for the given input where some values may be null.
119 * <p>
120 * The implementation decides on which argument take precedence.
121 * </p>
122 *
123 * @param file A file.
124 * @param url A URL.
125 * @param basePath A base path string.
126 * @param fileName A file name.
127 * @return A path string.
128 */
129 public abstract String getPath(File file, URL url, String basePath, String fileName);
130
131 /**
132 * Gets a URL for a base path and file name.
133 *
134 * @param basePath The base path.
135 * @param fileName The file name.
136 * @return a URL.
137 * @throws MalformedURLException if a problem occurs creating the URL.
138 */
139 public abstract URL getURL(String basePath, String fileName) throws MalformedURLException;
140
141 /**
142 * Locates a URL for a base path and file name.
143 *
144 * @param basePath The base path.
145 * @param fileName The file name.
146 * @return a URL.
147 */
148 public abstract URL locateFromURL(String basePath, String fileName);
149
150 /**
151 * Sets the FileOptionsProvider
152 *
153 * @param provider The FileOptionsProvider
154 */
155 public void setFileOptionsProvider(final FileOptionsProvider provider) {
156 this.optionsProvider = provider;
157 }
158
159 /**
160 * Sets the logger to be used by this FileSystem. This method makes it possible for clients to exactly control
161 * logging behavior. Per default a logger is set that will ignore all log messages. Derived classes that want to enable
162 * logging should call this method during their initialization with the logger to be used. Passing in a <strong>null</strong>
163 * argument disables logging.
164 *
165 * @param log the new logger
166 */
167 public void setLogger(final ConfigurationLogger log) {
168 this.log = log;
169 }
170 }