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.util.Map;
031
032 import org.apache.camel.spi.ClassResolver;
033
034 /**
035 * Helper class for loading resources on the classpath or file system.
036 */
037 public final class ResourceHelper {
038
039 private ResourceHelper() {
040 // utility class
041 }
042
043 /**
044 * Determines whether the URI has a scheme (e.g. file:, classpath: or http:)
045 *
046 * @param uri the URI
047 * @return <tt>true</tt> if the URI starts with a scheme
048 */
049 public static boolean hasScheme(String uri) {
050 if (uri == null) {
051 return false;
052 }
053
054 return uri.startsWith("file:") || uri.startsWith("classpath:") || uri.startsWith("http:");
055 }
056
057 /**
058 * Resolves the mandatory resource.
059 * <p/>
060 * If possible recommended to use {@link #resolveMandatoryResourceAsUrl(org.apache.camel.spi.ClassResolver, String)}
061 *
062 * @param classResolver the class resolver to load the resource from the classpath
063 * @param uri URI of the resource
064 * @return the resource as an {@link InputStream}. Remember to close this stream after usage.
065 * @throws java.io.IOException is thrown if the resource file could not be found or loaded as {@link InputStream}
066 */
067 public static InputStream resolveMandatoryResourceAsInputStream(ClassResolver classResolver, String uri) throws IOException {
068 if (uri.startsWith("file:")) {
069 uri = ObjectHelper.after(uri, "file:");
070 return new FileInputStream(uri);
071 } else if (uri.startsWith("http:")) {
072 URL url = new URL(uri);
073 URLConnection con = url.openConnection();
074 con.setUseCaches(false);
075 try {
076 return con.getInputStream();
077 } catch (IOException e) {
078 // close the http connection to avoid
079 // leaking gaps in case of an exception
080 if (con instanceof HttpURLConnection) {
081 ((HttpURLConnection) con).disconnect();
082 }
083 throw e;
084 }
085 } else if (uri.startsWith("classpath:")) {
086 uri = ObjectHelper.after(uri, "classpath:");
087 }
088
089 // load from classpath by default
090 InputStream is = classResolver.loadResourceAsStream(uri);
091 if (is == null) {
092 throw new FileNotFoundException("Cannot find resource in classpath for URI: " + uri);
093 } else {
094 return is;
095 }
096 }
097
098 /**
099 * Resolves the mandatory resource.
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.
104 * @throws java.io.FileNotFoundException is thrown if the resource file could not be found
105 * @throws java.net.MalformedURLException if the URI is malformed
106 */
107 public static URL resolveMandatoryResourceAsUrl(ClassResolver classResolver, String uri) throws FileNotFoundException, MalformedURLException {
108 if (uri.startsWith("file:")) {
109 // check if file exists first
110 String name = ObjectHelper.after(uri, "file:");
111 File file = new File(name);
112 if (!file.exists()) {
113 throw new FileNotFoundException("File " + file + " not found");
114 }
115 return new URL(uri);
116 } else if (uri.startsWith("http:")) {
117 return new URL(uri);
118 } else if (uri.startsWith("classpath:")) {
119 uri = ObjectHelper.after(uri, "classpath:");
120 }
121
122 // load from classpath by default
123 URL url = classResolver.loadResourceAsURL(uri);
124 if (url == null) {
125 throw new FileNotFoundException("Cannot find resource in classpath for URI: " + uri);
126 } else {
127 return url;
128 }
129 }
130
131 /**
132 * Is the given uri a http uri?
133 *
134 * @param uri the uri
135 * @return <tt>true</tt> if the uri starts with <tt>http:</tt> or <tt>https:</tt>
136 */
137 public static boolean isHttpUri(String uri) {
138 if (uri == null) {
139 return false;
140 }
141 return uri.startsWith("http:") || uri.startsWith("https:");
142 }
143
144 /**
145 * Appends the parameters to the given uri
146 *
147 * @param uri the uri
148 * @param parameters the additional parameters (will clear the map)
149 * @return a new uri with the additional parameters appended
150 * @throws URISyntaxException is thrown if the uri is invalid
151 */
152 public static String appendParameters(String uri, Map<String, Object> parameters) throws URISyntaxException {
153 // add additional parameters to the resource uri
154 if (!parameters.isEmpty()) {
155 String query = URISupport.createQueryString(parameters);
156 URI u = new URI(uri);
157 u = URISupport.createURIWithQuery(u, query);
158 parameters.clear();
159 return u.toString();
160 } else {
161 return uri;
162 }
163 }
164 }