001 /**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017 package org.apache.camel.util;
018
019 import java.io.File;
020 import java.io.FileInputStream;
021 import java.io.FileNotFoundException;
022 import java.io.IOException;
023 import java.io.InputStream;
024 import java.net.HttpURLConnection;
025 import java.net.MalformedURLException;
026 import java.net.URI;
027 import java.net.URISyntaxException;
028 import java.net.URL;
029 import java.net.URLConnection;
030 import java.net.URLDecoder;
031 import java.util.Map;
032
033 import org.apache.camel.spi.ClassResolver;
034 import org.slf4j.Logger;
035 import org.slf4j.LoggerFactory;
036
037 /**
038 * Helper class for loading resources on the classpath or file system.
039 */
040 public final class ResourceHelper {
041
042 private static final Logger LOG = LoggerFactory.getLogger(ResourceHelper.class);
043
044 private ResourceHelper() {
045 // utility class
046 }
047
048 /**
049 * Determines whether the URI has a scheme (e.g. file:, classpath: or http:)
050 *
051 * @param uri the URI
052 * @return <tt>true</tt> if the URI starts with a scheme
053 */
054 public static boolean hasScheme(String uri) {
055 if (uri == null) {
056 return false;
057 }
058
059 return uri.startsWith("file:") || uri.startsWith("classpath:") || uri.startsWith("http:");
060 }
061
062 /**
063 * Gets the scheme from the URI (e.g. file:, classpath: or http:)
064 *
065 * @param uri the uri
066 * @return the scheme, or <tt>null</tt> if no scheme
067 */
068 public static String getScheme(String uri) {
069 if (hasScheme(uri)) {
070 return uri.substring(0, uri.indexOf(":") + 1);
071 } else {
072 return null;
073 }
074 }
075
076 /**
077 * Resolves the mandatory resource.
078 * <p/>
079 * If possible recommended to use {@link #resolveMandatoryResourceAsUrl(org.apache.camel.spi.ClassResolver, String)}
080 *
081 * @param classResolver the class resolver to load the resource from the classpath
082 * @param uri URI of the resource
083 * @return the resource as an {@link InputStream}. Remember to close this stream after usage.
084 * @throws java.io.IOException is thrown if the resource file could not be found or loaded as {@link InputStream}
085 */
086 public static InputStream resolveMandatoryResourceAsInputStream(ClassResolver classResolver, String uri) throws IOException {
087 InputStream is = resolveResourceAsInputStream(classResolver, uri);
088 if (is == null) {
089 String resolvedName = resolveUriPath(uri);
090 throw new FileNotFoundException("Cannot find resource: " + resolvedName + " in classpath for URI: " + uri);
091 } else {
092 return is;
093 }
094 }
095
096 /**
097 * Resolves the resource.
098 * <p/>
099 * If possible recommended to use {@link #resolveMandatoryResourceAsUrl(org.apache.camel.spi.ClassResolver, String)}
100 *
101 * @param classResolver the class resolver to load the resource from the classpath
102 * @param uri URI of the resource
103 * @return the resource as an {@link InputStream}. Remember to close this stream after usage. Or <tt>null</tt> if not found.
104 * @throws java.io.IOException is thrown if error loading the resource
105 */
106 public static InputStream resolveResourceAsInputStream(ClassResolver classResolver, String uri) throws IOException {
107 if (uri.startsWith("file:")) {
108 uri = ObjectHelper.after(uri, "file:");
109 uri = tryDecodeUri(uri);
110 LOG.trace("Loading resource: {} from file system", uri);
111 return new FileInputStream(uri);
112 } else if (uri.startsWith("http:")) {
113 URL url = new URL(uri);
114 LOG.trace("Loading resource: {} from HTTP", uri);
115 URLConnection con = url.openConnection();
116 con.setUseCaches(false);
117 try {
118 return con.getInputStream();
119 } catch (IOException e) {
120 // close the http connection to avoid
121 // leaking gaps in case of an exception
122 if (con instanceof HttpURLConnection) {
123 ((HttpURLConnection) con).disconnect();
124 }
125 throw e;
126 }
127 } else if (uri.startsWith("classpath:")) {
128 uri = ObjectHelper.after(uri, "classpath:");
129 uri = tryDecodeUri(uri);
130 }
131
132 // load from classpath by default
133 String resolvedName = resolveUriPath(uri);
134 LOG.trace("Loading resource: {} from classpath", resolvedName);
135 return classResolver.loadResourceAsStream(resolvedName);
136 }
137
138 /**
139 * Resolves the mandatory resource.
140 *
141 * @param classResolver the class resolver to load the resource from the classpath
142 * @param uri uri of the resource
143 * @return the resource as an {@link java.net.URL}.
144 * @throws java.io.FileNotFoundException is thrown if the resource file could not be found
145 * @throws java.net.MalformedURLException if the URI is malformed
146 */
147 public static URL resolveMandatoryResourceAsUrl(ClassResolver classResolver, String uri) throws FileNotFoundException, MalformedURLException {
148 URL url = resolveResourceAsUrl(classResolver, uri);
149 if (url == null) {
150 String resolvedName = resolveUriPath(uri);
151 throw new FileNotFoundException("Cannot find resource: " + resolvedName + " in classpath for URI: " + uri);
152 } else {
153 return url;
154 }
155 }
156
157 /**
158 * Resolves the resource.
159 *
160 * @param classResolver the class resolver to load the resource from the classpath
161 * @param uri uri of the resource
162 * @return the resource as an {@link java.net.URL}. Or <tt>null</tt> if not found.
163 * @throws java.net.MalformedURLException if the URI is malformed
164 */
165 public static URL resolveResourceAsUrl(ClassResolver classResolver, String uri) throws MalformedURLException {
166 if (uri.startsWith("file:")) {
167 // check if file exists first
168 String name = ObjectHelper.after(uri, "file:");
169 uri = tryDecodeUri(uri);
170 LOG.trace("Loading resource: {} from file system", uri);
171 File file = new File(name);
172 if (!file.exists()) {
173 return null;
174 }
175 return new URL(uri);
176 } else if (uri.startsWith("http:")) {
177 LOG.trace("Loading resource: {} from HTTP", uri);
178 return new URL(uri);
179 } else if (uri.startsWith("classpath:")) {
180 uri = ObjectHelper.after(uri, "classpath:");
181 uri = tryDecodeUri(uri);
182 }
183
184 // load from classpath by default
185 String resolvedName = resolveUriPath(uri);
186 LOG.trace("Loading resource: {} from classpath", resolvedName);
187 return classResolver.loadResourceAsURL(resolvedName);
188 }
189
190 /**
191 * Is the given uri a http uri?
192 *
193 * @param uri the uri
194 * @return <tt>true</tt> if the uri starts with <tt>http:</tt> or <tt>https:</tt>
195 */
196 public static boolean isHttpUri(String uri) {
197 if (uri == null) {
198 return false;
199 }
200 return uri.startsWith("http:") || uri.startsWith("https:");
201 }
202
203 /**
204 * Appends the parameters to the given uri
205 *
206 * @param uri the uri
207 * @param parameters the additional parameters (will clear the map)
208 * @return a new uri with the additional parameters appended
209 * @throws URISyntaxException is thrown if the uri is invalid
210 */
211 public static String appendParameters(String uri, Map<String, Object> parameters) throws URISyntaxException {
212 // add additional parameters to the resource uri
213 if (!parameters.isEmpty()) {
214 String query = URISupport.createQueryString(parameters);
215 URI u = new URI(uri);
216 u = URISupport.createURIWithQuery(u, query);
217 parameters.clear();
218 return u.toString();
219 } else {
220 return uri;
221 }
222 }
223
224 /**
225 * Helper operation used to remove relative path notation from
226 * resources. Most critical for resources on the Classpath
227 * as resource loaders will not resolve the relative paths correctly.
228 *
229 * @param name the name of the resource to load
230 * @return the modified or unmodified string if there were no changes
231 */
232 private static String resolveUriPath(String name) {
233 // compact the path and use / as separator as that's used for loading resources on the classpath
234 return FileUtil.compactPath(name, '/');
235 }
236
237 /**
238 * Tries decoding the uri.
239 *
240 * @param uri the uri
241 * @return the decoded uri, or the original uri
242 */
243 private static String tryDecodeUri(String uri) {
244 try {
245 // try to decode as the uri may contain %20 for spaces etc
246 uri = URLDecoder.decode(uri, "UTF-8");
247 } catch (Exception e) {
248 LOG.trace("Error URL decoding uri using UTF-8 encoding: {}. This exception is ignored.", uri);
249 // ignore
250 }
251 return uri;
252 }
253
254 }