source: release-kits/lirk3/resources/gs3-release-maker/apache-ant-1.6.5/src/main/org/apache/tools/ant/launch/Locator.java@ 14982

Last change on this file since 14982 was 14982, checked in by oranfry, 16 years ago

initial import of LiRK3
File size: 9.5 KB
Line 
1/*
2 * Copyright 2003-2005 The Apache Software Foundation
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 */
17package org.apache.tools.ant.launch;
18
19import java.net.MalformedURLException;
20
21import java.net.URL;
22import java.io.File;
23import java.io.FilenameFilter;
24import java.text.CharacterIterator;
25import java.text.StringCharacterIterator;
26import java.util.Locale;
27
28/**
29 * The Locator is a utility class which is used to find certain items
30 * in the environment
31 *
32 * @since Ant 1.6
33 */
34public final class Locator {
35 /**
36 * Not instantiable
37 */
38 private Locator() {
39 }
40
41 /**
42 * Find the directory or jar file the class has been loaded from.
43 *
44 * @param c the class whose location is required.
45 * @return the file or jar with the class or null if we cannot
46 * determine the location.
47 *
48 * @since Ant 1.6
49 */
50 public static File getClassSource(Class c) {
51 String classResource = c.getName().replace('.', '/') + ".class";
52 return getResourceSource(c.getClassLoader(), classResource);
53 }
54
55 /**
56 * Find the directory or jar a give resource has been loaded from.
57 *
58 * @param c the classloader to be consulted for the source
59 * @param resource the resource whose location is required.
60 *
61 * @return the file with the resource source or null if
62 * we cannot determine the location.
63 *
64 * @since Ant 1.6
65 */
66 public static File getResourceSource(ClassLoader c, String resource) {
67 if (c == null) {
68 c = Locator.class.getClassLoader();
69 }
70
71 URL url = null;
72 if (c == null) {
73 url = ClassLoader.getSystemResource(resource);
74 } else {
75 url = c.getResource(resource);
76 }
77 if (url != null) {
78 String u = url.toString();
79 if (u.startsWith("jar:file:")) {
80 int pling = u.indexOf("!");
81 String jarName = u.substring(4, pling);
82 return new File(fromURI(jarName));
83 } else if (u.startsWith("file:")) {
84 int tail = u.indexOf(resource);
85 String dirName = u.substring(0, tail);
86 return new File(fromURI(dirName));
87 }
88 }
89 return null;
90 }
91
92 /**
93 * Constructs a file path from a <code>file:</code> URI.
94 *
95 * <p>Will be an absolute path if the given URI is absolute.</p>
96 *
97 * <p>Swallows '%' that are not followed by two characters,
98 * doesn't deal with non-ASCII characters.</p>
99 *
100 * @param uri the URI designating a file in the local filesystem.
101 * @return the local file system path for the file.
102 * @since Ant 1.6
103 */
104 public static String fromURI(String uri) {
105 URL url = null;
106 try {
107 url = new URL(uri);
108 } catch (MalformedURLException emYouEarlEx) {
109 }
110 if (url == null || !("file".equals(url.getProtocol()))) {
111 throw new IllegalArgumentException("Can only handle valid file: URIs");
112 }
113 StringBuffer buf = new StringBuffer(url.getHost());
114 if (buf.length() > 0) {
115 buf.insert(0, File.separatorChar).insert(0, File.separatorChar);
116 }
117
118 String file = url.getFile();
119 int queryPos = file.indexOf('?');
120 buf.append((queryPos < 0) ? file : file.substring(0, queryPos));
121
122 uri = buf.toString().replace('/', File.separatorChar);
123
124 if (File.pathSeparatorChar == ';' && uri.startsWith("\\") && uri.length() > 2
125 && Character.isLetter(uri.charAt(1)) && uri.lastIndexOf(':') > -1) {
126 uri = uri.substring(1);
127 }
128
129 String path = decodeUri(uri);
130 return path;
131 }
132
133 /**
134 * Decodes an Uri with % characters.
135 * @param uri String with the uri possibly containing % characters.
136 * @return The decoded Uri
137 */
138 private static String decodeUri(String uri) {
139 if (uri.indexOf('%') == -1)
140 {
141 return uri;
142 }
143 StringBuffer sb = new StringBuffer();
144 CharacterIterator iter = new StringCharacterIterator(uri);
145 for (char c = iter.first(); c != CharacterIterator.DONE;
146 c = iter.next()) {
147 if (c == '%') {
148 char c1 = iter.next();
149 if (c1 != CharacterIterator.DONE) {
150 int i1 = Character.digit(c1, 16);
151 char c2 = iter.next();
152 if (c2 != CharacterIterator.DONE) {
153 int i2 = Character.digit(c2, 16);
154 sb.append((char) ((i1 << 4) + i2));
155 }
156 }
157 } else {
158 sb.append(c);
159 }
160 }
161 String path = sb.toString();
162 return path;
163 }
164
165 /**
166 * Get the File necessary to load the Sun compiler tools. If the classes
167 * are available to this class, then no additional URL is required and
168 * null is returned. This may be because the classes are explicitly in the
169 * class path or provided by the JVM directly
170 *
171 * @return the tools jar as a File if required, null otherwise
172 */
173 public static File getToolsJar() {
174 // firstly check if the tools jar is already in the classpath
175 boolean toolsJarAvailable = false;
176
177 try {
178 // just check whether this throws an exception
179 Class.forName("com.sun.tools.javac.Main");
180 toolsJarAvailable = true;
181 } catch (Exception e) {
182 try {
183 Class.forName("sun.tools.javac.Main");
184 toolsJarAvailable = true;
185 } catch (Exception e2) {
186 // ignore
187 }
188 }
189
190 if (toolsJarAvailable) {
191 return null;
192 }
193
194 // couldn't find compiler - try to find tools.jar
195 // based on java.home setting
196 String javaHome = System.getProperty("java.home");
197 if (javaHome.toLowerCase(Locale.US).endsWith("jre")) {
198 javaHome = javaHome.substring(0, javaHome.length() - 4);
199 }
200 File toolsJar = new File(javaHome + "/lib/tools.jar");
201 if (!toolsJar.exists()) {
202 System.out.println("Unable to locate tools.jar. "
203 + "Expected to find it in " + toolsJar.getPath());
204 return null;
205 }
206 return toolsJar;
207 }
208
209 /**
210 * Get an array or URLs representing all of the jar files in the
211 * given location. If the location is a file, it is returned as the only
212 * element of the array. If the location is a directory, it is scanned for
213 * jar files
214 *
215 * @param location the location to scan for Jars
216 *
217 * @return an array of URLs for all jars in the given location.
218 *
219 * @exception MalformedURLException if the URLs for the jars cannot be
220 * formed
221 */
222 public static URL[] getLocationURLs(File location)
223 throws MalformedURLException {
224 return getLocationURLs(location, new String[]{".jar"});
225 }
226
227 /**
228 * Get an array or URLs representing all of the files of a given set of
229 * extensions in the given location. If the location is a file, it is
230 * returned as the only element of the array. If the location is a
231 * directory, it is scanned for matching files
232 *
233 * @param location the location to scan for files
234 * @param extensions an array of extension that are to match in the
235 * directory search
236 *
237 * @return an array of URLs of matching files
238 * @exception MalformedURLException if the URLs for the files cannot be
239 * formed
240 */
241 public static URL[] getLocationURLs(File location,
242 final String[] extensions)
243 throws MalformedURLException {
244 URL[] urls = new URL[0];
245
246 if (!location.exists()) {
247 return urls;
248 }
249
250 if (!location.isDirectory()) {
251 urls = new URL[1];
252 String path = location.getPath();
253 for (int i = 0; i < extensions.length; ++i) {
254 if (path.toLowerCase().endsWith(extensions[i])) {
255 urls[0] = location.toURL();
256 break;
257 }
258 }
259 return urls;
260 }
261
262 File[] matches = location.listFiles(
263 new FilenameFilter() {
264 public boolean accept(File dir, String name) {
265 for (int i = 0; i < extensions.length; ++i) {
266 if (name.toLowerCase().endsWith(extensions[i])) {
267 return true;
268 }
269 }
270 return false;
271 }
272 });
273
274 urls = new URL[matches.length];
275 for (int i = 0; i < matches.length; ++i) {
276 urls[i] = matches[i].toURL();
277 }
278 return urls;
279 }
280}
281
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