1 /*
2 * Copyright (c) 2016, 2017, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25 package jdk.internal.jrtfs;
26
27 import java.io.*;
28 import java.net.MalformedURLException;
29 import java.net.URL;
30 import java.net.URLClassLoader;
31 import java.nio.channels.*;
32 import java.nio.file.*;
33 import java.nio.file.DirectoryStream.Filter;
34 import java.nio.file.attribute.*;
35 import java.nio.file.spi.FileSystemProvider;
36 import java.net.URI;
37 import java.security.AccessController;
38 import java.security.PrivilegedAction;
39 import java.util.HashMap;
40 import java.util.Map;
41 import java.util.Objects;
42 import java.util.Set;
43 import java.util.concurrent.ExecutorService;
44
45 /**
46 * File system provider for jrt file systems. Conditionally creates jrt fs on
47 * .jimage file or exploded modules directory of underlying JDK.
48 *
49 * @implNote This class needs to maintain JDK 8 source compatibility.
50 *
51 * It is used internally in the JDK to implement jimage/jrtfs access,
52 * but also compiled and delivered as part of the jrtfs.jar to support access
53 * to the jimage file provided by the shipped JDK by tools running on JDK 8.
54 */
55 public final class JrtFileSystemProvider extends FileSystemProvider {
56
57 private volatile FileSystem theFileSystem;
58
59 public JrtFileSystemProvider() {
60 }
61
62 @Override
63 public String getScheme() {
64 return "jrt";
65 }
66
67 /**
68 * Need RuntimePermission "accessSystemModules" to create or get jrt:/
69 */
70 private void checkPermission() {
71 SecurityManager sm = System.getSecurityManager();
72 if (sm != null) {
73 RuntimePermission perm = new RuntimePermission("accessSystemModules");
74 sm.checkPermission(perm);
75 }
76 }
77
78 private void checkUri(URI uri) {
79 if (!uri.getScheme().equalsIgnoreCase(getScheme())) {
80 throw new IllegalArgumentException("URI does not match this provider");
81 }
82 if (uri.getAuthority() != null) {
83 throw new IllegalArgumentException("Authority component present");
84 }
85 if (uri.getPath() == null) {
86 throw new IllegalArgumentException("Path component is undefined");
87 }
88 if (!uri.getPath().equals("/")) {
89 throw new IllegalArgumentException("Path component should be '/'");
90 }
91 if (uri.getQuery() != null) {
92 throw new IllegalArgumentException("Query component present");
93 }
94 if (uri.getFragment() != null) {
95 throw new IllegalArgumentException("Fragment component present");
96 }
97 }
98
99 @Override
100 public FileSystem newFileSystem(URI uri, Map<String, ?> env)
101 throws IOException {
102 Objects.requireNonNull(env);
103 checkPermission();
104 checkUri(uri);
105 if (env.containsKey("java.home")) {
106 return newFileSystem((String)env.get("java.home"), uri, env);
107 } else {
108 return new JrtFileSystem(this, env);
109 }
110 }
111
112 private static final String JRT_FS_JAR = "jrt-fs.jar";
113 private FileSystem newFileSystem(String targetHome, URI uri, Map<String, ?> env)
114 throws IOException {
115 Objects.requireNonNull(targetHome);
116 Path jrtfs = FileSystems.getDefault().getPath(targetHome, "lib", JRT_FS_JAR);
117 if (Files.notExists(jrtfs)) {
118 throw new IOException(jrtfs.toString() + " not exist");
119 }
120 Map<String,?> newEnv = new HashMap<>(env);
121 newEnv.remove("java.home");
122 ClassLoader cl = newJrtFsLoader(jrtfs);
123 try {
124 Class<?> c = Class.forName(JrtFileSystemProvider.class.getName(), false, cl);
125 @SuppressWarnings("deprecation")
126 Object tmp = c.newInstance();
127 return ((FileSystemProvider)tmp).newFileSystem(uri, newEnv);
128 } catch (ClassNotFoundException |
129 IllegalAccessException |
130 InstantiationException e) {
131 throw new IOException(e);
132 }
133 }
134
135 private static class JrtFsLoader extends URLClassLoader {
136 JrtFsLoader(URL[] urls) {
137 super(urls);
138 }
139 @Override
140 protected Class<?> loadClass(String cn, boolean resolve)
141 throws ClassNotFoundException
142 {
143 Class<?> c = findLoadedClass(cn);
144 if (c == null) {
145 URL u = findResource(cn.replace('.', '/') + ".class");
146 if (u != null) {
147 c = findClass(cn);
148 } else {
149 return super.loadClass(cn, resolve);
150 }
151 }
152 if (resolve)
153 resolveClass(c);
154 return c;
155 }
156 }
157
158 private static URLClassLoader newJrtFsLoader(Path jrtfs) {
159 final URL url;
160 try {
161 url = jrtfs.toUri().toURL();
162 } catch (MalformedURLException mue) {
163 throw new IllegalArgumentException(mue);
164 }
165
166 final URL[] urls = new URL[] { url };
167 return AccessController.doPrivileged(
168 new PrivilegedAction<URLClassLoader>() {
169 @Override
170 public URLClassLoader run() {
171 return new JrtFsLoader(urls);
172 }
173 }
174 );
175 }
176
177 @Override
178 public Path getPath(URI uri) {
179 checkPermission();
180 if (!uri.getScheme().equalsIgnoreCase(getScheme())) {
181 throw new IllegalArgumentException("URI does not match this provider");
182 }
183 if (uri.getAuthority() != null) {
184 throw new IllegalArgumentException("Authority component present");
185 }
186 if (uri.getQuery() != null) {
187 throw new IllegalArgumentException("Query component present");
188 }
189 if (uri.getFragment() != null) {
190 throw new IllegalArgumentException("Fragment component present");
191 }
192 String path = uri.getPath();
193 if (path == null || path.charAt(0) != '/') {
194 throw new IllegalArgumentException("Invalid path component");
195 }
196 return getTheFileSystem().getPath(path);
197 }
198
199 private FileSystem getTheFileSystem() {
200 checkPermission();
201 FileSystem fs = this.theFileSystem;
202 if (fs == null) {
203 synchronized (this) {
204 fs = this.theFileSystem;
205 if (fs == null) {
206 try {
207 this.theFileSystem = fs = new JrtFileSystem(this, null);
208 } catch (IOException ioe) {
209 throw new InternalError(ioe);
210 }
211 }
212 }
213 }
214 return fs;
215 }
216
217 @Override
218 public FileSystem getFileSystem(URI uri) {
219 checkPermission();
220 checkUri(uri);
221 return getTheFileSystem();
222 }
223
224 // Checks that the given file is a JrtPath
225 static final JrtPath toJrtPath(Path path) {
226 Objects.requireNonNull(path, "path");
227 if (!(path instanceof JrtPath)) {
228 throw new ProviderMismatchException();
229 }
230 return (JrtPath) path;
231 }
232
233 @Override
234 public void checkAccess(Path path, AccessMode... modes) throws IOException {
235 toJrtPath(path).checkAccess(modes);
236 }
237
238 @Override
239 public Path readSymbolicLink(Path link) throws IOException {
240 return toJrtPath(link).readSymbolicLink();
241 }
242
243 @Override
244 public void copy(Path src, Path target, CopyOption... options)
245 throws IOException {
246 toJrtPath(src).copy(toJrtPath(target), options);
247 }
248
249 @Override
250 public void createDirectory(Path path, FileAttribute<?>... attrs)
251 throws IOException {
252 toJrtPath(path).createDirectory(attrs);
253 }
254
255 @Override
256 public final void delete(Path path) throws IOException {
257 toJrtPath(path).delete();
258 }
259
260 @Override
261 @SuppressWarnings("unchecked")
262 public <V extends FileAttributeView> V
263 getFileAttributeView(Path path, Class<V> type, LinkOption... options) {
264 return JrtFileAttributeView.get(toJrtPath(path), type, options);
265 }
266
267 @Override
268 public FileStore getFileStore(Path path) throws IOException {
269 return toJrtPath(path).getFileStore();
270 }
271
272 @Override
273 public boolean isHidden(Path path) {
274 return toJrtPath(path).isHidden();
275 }
276
277 @Override
278 public boolean isSameFile(Path path, Path other) throws IOException {
279 return toJrtPath(path).isSameFile(other);
280 }
281
282 @Override
283 public void move(Path src, Path target, CopyOption... options)
284 throws IOException {
285 toJrtPath(src).move(toJrtPath(target), options);
286 }
287
288 @Override
289 public AsynchronousFileChannel newAsynchronousFileChannel(Path path,
290 Set<? extends OpenOption> options,
291 ExecutorService exec,
292 FileAttribute<?>... attrs)
293 throws IOException {
294 throw new UnsupportedOperationException();
295 }
296
297 @Override
298 public SeekableByteChannel newByteChannel(Path path,
299 Set<? extends OpenOption> options,
300 FileAttribute<?>... attrs)
301 throws IOException {
302 return toJrtPath(path).newByteChannel(options, attrs);
303 }
304
305 @Override
306 public DirectoryStream<Path> newDirectoryStream(
307 Path path, Filter<? super Path> filter) throws IOException {
308 return toJrtPath(path).newDirectoryStream(filter);
309 }
310
311 @Override
312 public FileChannel newFileChannel(Path path,
313 Set<? extends OpenOption> options,
314 FileAttribute<?>... attrs)
315 throws IOException {
316 return toJrtPath(path).newFileChannel(options, attrs);
317 }
318
319 @Override
320 public InputStream newInputStream(Path path, OpenOption... options)
321 throws IOException {
322 return toJrtPath(path).newInputStream(options);
323 }
324
325 @Override
326 public OutputStream newOutputStream(Path path, OpenOption... options)
327 throws IOException {
328 return toJrtPath(path).newOutputStream(options);
329 }
330
331 @Override
332 @SuppressWarnings("unchecked") // Cast to A
333 public <A extends BasicFileAttributes> A
334 readAttributes(Path path, Class<A> type, LinkOption... options)
335 throws IOException {
336 if (type == BasicFileAttributes.class || type == JrtFileAttributes.class) {
337 return (A) toJrtPath(path).getAttributes(options);
338 }
339 return null;
340 }
341
342 @Override
343 public Map<String, Object>
344 readAttributes(Path path, String attribute, LinkOption... options)
345 throws IOException {
346 return toJrtPath(path).readAttributes(attribute, options);
347 }
348
349 @Override
350 public void setAttribute(Path path, String attribute,
351 Object value, LinkOption... options)
352 throws IOException {
353 toJrtPath(path).setAttribute(attribute, value, options);
354 }
355 }