1 /*
2 * Copyright 2009-2021 the original author or authors.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16 package org.apache.ibatis.io;
17
18 import java.io.File;
19 import java.io.IOException;
20 import java.io.InputStream;
21 import java.io.InputStreamReader;
22 import java.io.Reader;
23 import java.net.URL;
24 import java.net.URLConnection;
25 import java.nio.charset.Charset;
26 import java.util.Properties;
27
28 /**
29 * A class to simplify access to resources through the classloader.
30 *
31 * @author Clinton Begin
32 */
33 public class Resources {
34
35 private static ClassLoaderWrapper classLoaderWrapper = new ClassLoaderWrapper();
36
37 /**
38 * Charset to use when calling getResourceAsReader.
39 * null means use the system default.
40 */
41 private static Charset charset;
42
43 Resources() {
44 }
45
46 /**
47 * Returns the default classloader (may be null).
48 *
49 * @return The default classloader
50 */
51 public static ClassLoader getDefaultClassLoader() {
52 return classLoaderWrapper.defaultClassLoader;
53 }
54
55 /**
56 * Sets the default classloader
57 *
58 * @param defaultClassLoader - the new default ClassLoader
59 */
60 public static void setDefaultClassLoader(ClassLoader defaultClassLoader) {
61 classLoaderWrapper.defaultClassLoader = defaultClassLoader;
62 }
63
64 /**
65 * Returns the URL of the resource on the classpath
66 *
67 * @param resource The resource to find
68 * @return The resource
69 * @throws java.io.IOException If the resource cannot be found or read
70 */
71 public static URL getResourceURL(String resource) throws IOException {
72 // issue #625
73 return getResourceURL(null, resource);
74 }
75
76 /**
77 * Returns the URL of the resource on the classpath
78 *
79 * @param loader The classloader used to fetch the resource
80 * @param resource The resource to find
81 * @return The resource
82 * @throws java.io.IOException If the resource cannot be found or read
83 */
84 public static URL getResourceURL(ClassLoader loader, String resource) throws IOException {
85 URL url = classLoaderWrapper.getResourceAsURL(resource, loader);
86 if (url == null) {
87 throw new IOException("Could not find resource " + resource);
88 }
89 return url;
90 }
91
92 /**
93 * Returns a resource on the classpath as a Stream object
94 *
95 * @param resource The resource to find
96 * @return The resource
97 * @throws java.io.IOException If the resource cannot be found or read
98 */
99 public static InputStream getResourceAsStream(String resource) throws IOException {
100 return getResourceAsStream(null, resource);
101 }
102
103 /**
104 * Returns a resource on the classpath as a Stream object
105 *
106 * @param loader The classloader used to fetch the resource
107 * @param resource The resource to find
108 * @return The resource
109 * @throws java.io.IOException If the resource cannot be found or read
110 */
111 public static InputStream getResourceAsStream(ClassLoader loader, String resource) throws IOException {
112 InputStream in = classLoaderWrapper.getResourceAsStream(resource, loader);
113 if (in == null) {
114 throw new IOException("Could not find resource " + resource);
115 }
116 return in;
117 }
118
119 /**
120 * Returns a resource on the classpath as a Properties object
121 *
122 * @param resource The resource to find
123 * @return The resource
124 * @throws java.io.IOException If the resource cannot be found or read
125 */
126 public static Properties getResourceAsProperties(String resource) throws IOException {
127 Properties props = new Properties();
128 try (InputStream in = getResourceAsStream(resource)) {
129 props.load(in);
130 }
131 return props;
132 }
133
134 /**
135 * Returns a resource on the classpath as a Properties object
136 *
137 * @param loader The classloader used to fetch the resource
138 * @param resource The resource to find
139 * @return The resource
140 * @throws java.io.IOException If the resource cannot be found or read
141 */
142 public static Properties getResourceAsProperties(ClassLoader loader, String resource) throws IOException {
143 Properties props = new Properties();
144 try (InputStream in = getResourceAsStream(loader, resource)) {
145 props.load(in);
146 }
147 return props;
148 }
149
150 /**
151 * Returns a resource on the classpath as a Reader object
152 *
153 * @param resource The resource to find
154 * @return The resource
155 * @throws java.io.IOException If the resource cannot be found or read
156 */
157 public static Reader getResourceAsReader(String resource) throws IOException {
158 Reader reader;
159 if (charset == null) {
160 reader = new InputStreamReader(getResourceAsStream(resource));
161 } else {
162 reader = new InputStreamReader(getResourceAsStream(resource), charset);
163 }
164 return reader;
165 }
166
167 /**
168 * Returns a resource on the classpath as a Reader object
169 *
170 * @param loader The classloader used to fetch the resource
171 * @param resource The resource to find
172 * @return The resource
173 * @throws java.io.IOException If the resource cannot be found or read
174 */
175 public static Reader getResourceAsReader(ClassLoader loader, String resource) throws IOException {
176 Reader reader;
177 if (charset == null) {
178 reader = new InputStreamReader(getResourceAsStream(loader, resource));
179 } else {
180 reader = new InputStreamReader(getResourceAsStream(loader, resource), charset);
181 }
182 return reader;
183 }
184
185 /**
186 * Returns a resource on the classpath as a File object
187 *
188 * @param resource The resource to find
189 * @return The resource
190 * @throws java.io.IOException If the resource cannot be found or read
191 */
192 public static File getResourceAsFile(String resource) throws IOException {
193 return new File(getResourceURL(resource).getFile());
194 }
195
196 /**
197 * Returns a resource on the classpath as a File object
198 *
199 * @param loader - the classloader used to fetch the resource
200 * @param resource - the resource to find
201 * @return The resource
202 * @throws java.io.IOException If the resource cannot be found or read
203 */
204 public static File getResourceAsFile(ClassLoader loader, String resource) throws IOException {
205 return new File(getResourceURL(loader, resource).getFile());
206 }
207
208 /**
209 * Gets a URL as an input stream
210 *
211 * @param urlString - the URL to get
212 * @return An input stream with the data from the URL
213 * @throws java.io.IOException If the resource cannot be found or read
214 */
215 public static InputStream getUrlAsStream(String urlString) throws IOException {
216 URL url = new URL(urlString);
217 URLConnection conn = url.openConnection();
218 return conn.getInputStream();
219 }
220
221 /**
222 * Gets a URL as a Reader
223 *
224 * @param urlString - the URL to get
225 * @return A Reader with the data from the URL
226 * @throws java.io.IOException If the resource cannot be found or read
227 */
228 public static Reader getUrlAsReader(String urlString) throws IOException {
229 Reader reader;
230 if (charset == null) {
231 reader = new InputStreamReader(getUrlAsStream(urlString));
232 } else {
233 reader = new InputStreamReader(getUrlAsStream(urlString), charset);
234 }
235 return reader;
236 }
237
238 /**
239 * Gets a URL as a Properties object
240 *
241 * @param urlString - the URL to get
242 * @return A Properties object with the data from the URL
243 * @throws java.io.IOException If the resource cannot be found or read
244 */
245 public static Properties getUrlAsProperties(String urlString) throws IOException {
246 Properties props = new Properties();
247 try (InputStream in = getUrlAsStream(urlString)) {
248 props.load(in);
249 }
250 return props;
251 }
252
253 /**
254 * Loads a class
255 *
256 * @param className - the class to fetch
257 * @return The loaded class
258 * @throws ClassNotFoundException If the class cannot be found (duh!)
259 */
260 public static Class<?> classForName(String className) throws ClassNotFoundException {
261 return classLoaderWrapper.classForName(className);
262 }
263
264 public static Charset getCharset() {
265 return charset;
266 }
267
268 public static void setCharset(Charset charset) {
269 Resources.charset = charset;
270 }
271
272 }