source: josm/trunk/src/org/openstreetmap/josm/io/CachedFile.java@ 15293

Last change on this file since 15293 was 15293, checked in by Don-vip, 5 years ago

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1// License: GPL. For details, see LICENSE file.
2package org.openstreetmap.josm.io;
3
4import static org.openstreetmap.josm.tools.I18n.tr;
5
6import java.io.BufferedReader;
7import java.io.Closeable;
8import java.io.File;
9import java.io.IOException;
10import java.io.InputStream;
11import java.math.BigInteger;
12import java.net.HttpURLConnection;
13import java.net.MalformedURLException;
14import java.net.URL;
15import java.nio.charset.StandardCharsets;
16import java.nio.file.Files;
17import java.nio.file.InvalidPathException;
18import java.nio.file.StandardCopyOption;
19import java.security.MessageDigest;
20import java.security.NoSuchAlgorithmException;
21import java.util.ArrayList;
22import java.util.Arrays;
23import java.util.Enumeration;
24import java.util.List;
25import java.util.Map;
26import java.util.concurrent.ConcurrentHashMap;
27import java.util.concurrent.TimeUnit;
28import java.util.zip.ZipEntry;
29import java.util.zip.ZipFile;
30
31import org.openstreetmap.josm.data.Preferences;
32import org.openstreetmap.josm.spi.preferences.Config;
33import org.openstreetmap.josm.tools.HttpClient;
34import org.openstreetmap.josm.tools.Logging;
35import org.openstreetmap.josm.tools.Pair;
36import org.openstreetmap.josm.tools.PlatformManager;
37import org.openstreetmap.josm.tools.Utils;
38
39/**
40 * Downloads a file and caches it on disk in order to reduce network load.
41 *
42 * Supports URLs, local files, and a custom scheme (<code>resource:</code>) to get
43 * resources from the current *.jar file. (Local caching is only done for URLs.)
44 * <p>
45 * The mirrored file is only downloaded if it has been more than 7 days since
46 * last download. (Time can be configured.)
47 * <p>
48 * The file content is normally accessed with {@link #getInputStream()}, but
49 * you can also get the mirrored copy with {@link #getFile()}.
50 */
51public class CachedFile implements Closeable {
52
53 /**
54 * Caching strategy.
55 */
56 public enum CachingStrategy {
57 /**
58 * If cached file on disk is older than a certain time (7 days by default),
59 * consider the cache stale and try to download the file again.
60 */
61 MaxAge,
62 /**
63 * Similar to MaxAge, considers the cache stale when a certain age is
64 * exceeded. In addition, a If-Modified-Since HTTP header is added.
65 * When the server replies "304 Not Modified", this is considered the same
66 * as a full download.
67 */
68 IfModifiedSince
69 }
70
71 protected String name;
72 protected long maxAge;
73 protected String destDir;
74 protected String httpAccept;
75 protected CachingStrategy cachingStrategy;
76
77 private boolean fastFail;
78 private HttpClient activeConnection;
79 protected File cacheFile;
80 protected boolean initialized;
81 protected String parameter;
82
83 public static final long DEFAULT_MAXTIME = -1L;
84 public static final long DAYS = TimeUnit.DAYS.toSeconds(1); // factor to get caching time in days
85
86 private final Map<String, String> httpHeaders = new ConcurrentHashMap<>();
87
88 /**
89 * Constructs a CachedFile object from a given filename, URL or internal resource.
90 *
91 * @param name can be:<ul>
92 * <li>relative or absolute file name</li>
93 * <li>{@code file:///SOME/FILE} the same as above</li>
94 * <li>{@code http://...} a URL. It will be cached on disk.</li>
95 * <li>{@code resource://SOME/FILE} file from the classpath (usually in the current *.jar)</li>
96 * <li>{@code josmdir://SOME/FILE} file inside josm user data directory (since r7058)</li>
97 * <li>{@code josmplugindir://SOME/FILE} file inside josm plugin directory (since r7834)</li></ul>
98 */
99 public CachedFile(String name) {
100 this.name = name;
101 }
102
103 /**
104 * Set the name of the resource.
105 * @param name can be:<ul>
106 * <li>relative or absolute file name</li>
107 * <li>{@code file:///SOME/FILE} the same as above</li>
108 * <li>{@code http://...} a URL. It will be cached on disk.</li>
109 * <li>{@code resource://SOME/FILE} file from the classpath (usually in the current *.jar)</li>
110 * <li>{@code josmdir://SOME/FILE} file inside josm user data directory (since r7058)</li>
111 * <li>{@code josmplugindir://SOME/FILE} file inside josm plugin directory (since r7834)</li></ul>
112 * @return this object
113 */
114 public CachedFile setName(String name) {
115 this.name = name;
116 return this;
117 }
118
119 /**
120 * Set maximum age of cache file. Only applies to URLs.
121 * When this time has passed after the last download of the file, the
122 * cache is considered stale and a new download will be attempted.
123 * @param maxAge the maximum cache age in seconds
124 * @return this object
125 */
126 public CachedFile setMaxAge(long maxAge) {
127 this.maxAge = maxAge;
128 return this;
129 }
130
131 /**
132 * Set the destination directory for the cache file. Only applies to URLs.
133 * @param destDir the destination directory
134 * @return this object
135 */
136 public CachedFile setDestDir(String destDir) {
137 this.destDir = destDir;
138 return this;
139 }
140
141 /**
142 * Set the accepted MIME types sent in the HTTP Accept header. Only applies to URLs.
143 * @param httpAccept the accepted MIME types
144 * @return this object
145 */
146 public CachedFile setHttpAccept(String httpAccept) {
147 this.httpAccept = httpAccept;
148 return this;
149 }
150
151 /**
152 * Set the caching strategy. Only applies to URLs.
153 * @param cachingStrategy caching strategy
154 * @return this object
155 */
156 public CachedFile setCachingStrategy(CachingStrategy cachingStrategy) {
157 this.cachingStrategy = cachingStrategy;
158 return this;
159 }
160
161 /**
162 * Sets the http headers. Only applies to URL pointing to http or https resources
163 * @param headers that should be sent together with request
164 * @return this object
165 */
166 public CachedFile setHttpHeaders(Map<String, String> headers) {
167 this.httpHeaders.putAll(headers);
168 return this;
169 }
170
171 /**
172 * Sets whether opening HTTP connections should fail fast, i.e., whether a
173 * {@link HttpClient#setConnectTimeout(int) low connect timeout} should be used.
174 * @param fastFail whether opening HTTP connections should fail fast
175 */
176 public void setFastFail(boolean fastFail) {
177 this.fastFail = fastFail;
178 }
179
180 /**
181 * Sets additional URL parameter (used e.g. for maps)
182 * @param parameter the URL parameter
183 * @since 13536
184 */
185 public void setParam(String parameter) {
186 this.parameter = parameter;
187 }
188
189 public String getName() {
190 if (parameter != null)
191 return name.replaceAll("%<(.*)>", "");
192 return name;
193 }
194
195 /**
196 * Returns maximum age of cache file. Only applies to URLs.
197 * When this time has passed after the last download of the file, the
198 * cache is considered stale and a new download will be attempted.
199 * @return the maximum cache age in seconds
200 */
201 public long getMaxAge() {
202 return maxAge;
203 }
204
205 public String getDestDir() {
206 return destDir;
207 }
208
209 public String getHttpAccept() {
210 return httpAccept;
211 }
212
213 public CachingStrategy getCachingStrategy() {
214 return cachingStrategy;
215 }
216
217 /**
218 * Get InputStream to the requested resource.
219 * @return the InputStream
220 * @throws IOException when the resource with the given name could not be retrieved
221 * @throws InvalidPathException if a Path object cannot be constructed from the inner file path
222 */
223 public InputStream getInputStream() throws IOException {
224 File file = getFile();
225 if (file == null) {
226 if (name != null && name.startsWith("resource://")) {
227 String resourceName = name.substring("resource:/".length());
228 InputStream is = Utils.getResourceAsStream(getClass(), resourceName);
229 if (is == null) {
230 throw new IOException(tr("Failed to open input stream for resource ''{0}''", name));
231 }
232 return is;
233 } else {
234 throw new IOException("No file found for: "+name);
235 }
236 }
237 return Files.newInputStream(file.toPath());
238 }
239
240 /**
241 * Get the full content of the requested resource as a byte array.
242 * @return the full content of the requested resource as byte array
243 * @throws IOException in case of an I/O error
244 */
245 public byte[] getByteContent() throws IOException {
246 return Utils.readBytesFromStream(getInputStream());
247 }
248
249 /**
250 * Returns {@link #getInputStream()} wrapped in a buffered reader.
251 * <p>
252 * Detects Unicode charset in use utilizing {@link UTFInputStreamReader}.
253 *
254 * @return buffered reader
255 * @throws IOException if any I/O error occurs
256 * @since 9411
257 */
258 public BufferedReader getContentReader() throws IOException {
259 return new BufferedReader(UTFInputStreamReader.create(getInputStream()));
260 }
261
262 /**
263 * Get local file for the requested resource.
264 * @return The local cache file for URLs. If the resource is a local file,
265 * returns just that file.
266 * @throws IOException when the resource with the given name could not be retrieved
267 */
268 public synchronized File getFile() throws IOException {
269 if (initialized)
270 return cacheFile;
271 initialized = true;
272 URL url;
273 try {
274 url = new URL(name);
275 if ("file".equals(url.getProtocol())) {
276 cacheFile = new File(name.substring("file:/".length() - 1));
277 if (!cacheFile.exists()) {
278 cacheFile = new File(name.substring("file://".length() - 1));
279 }
280 } else {
281 try {
282 cacheFile = checkLocal(url);
283 } catch (SecurityException e) {
284 throw new IOException(e);
285 }
286 }
287 } catch (MalformedURLException e) {
288 if (name == null || name.startsWith("resource://")) {
289 return null;
290 } else if (name.startsWith("josmdir://")) {
291 cacheFile = new File(Config.getDirs().getUserDataDirectory(false), name.substring("josmdir://".length()));
292 } else if (name.startsWith("josmplugindir://")) {
293 cacheFile = new File(Preferences.main().getPluginsDirectory(), name.substring("josmplugindir://".length()));
294 } else {
295 cacheFile = new File(name);
296 }
297 }
298 if (cacheFile == null)
299 throw new IOException("Unable to get cache file for "+getName());
300 return cacheFile;
301 }
302
303 /**
304 * Looks for a certain entry inside a zip file and returns the entry path.
305 *
306 * Replies a file in the top level directory of the ZIP file which has an
307 * extension <code>extension</code>. If more than one files have this
308 * extension, the last file whose name includes <code>namepart</code>
309 * is opened.
310 *
311 * @param extension the extension of the file we're looking for
312 * @param namepart the name part
313 * @return The zip entry path of the matching file. <code>null</code> if this cached file
314 * doesn't represent a zip file or if there was no matching
315 * file in the ZIP file.
316 */
317 public String findZipEntryPath(String extension, String namepart) {
318 Pair<String, InputStream> ze = findZipEntryImpl(extension, namepart);
319 if (ze == null) return null;
320 return ze.a;
321 }
322
323 /**
324 * Like {@link #findZipEntryPath}, but returns the corresponding InputStream.
325 * @param extension the extension of the file we're looking for
326 * @param namepart the name part
327 * @return InputStream to the matching file. <code>null</code> if this cached file
328 * doesn't represent a zip file or if there was no matching
329 * file in the ZIP file.
330 * @since 6148
331 */
332 public InputStream findZipEntryInputStream(String extension, String namepart) {
333 Pair<String, InputStream> ze = findZipEntryImpl(extension, namepart);
334 if (ze == null) return null;
335 return ze.b;
336 }
337
338 private Pair<String, InputStream> findZipEntryImpl(String extension, String namepart) {
339 File file = null;
340 try {
341 file = getFile();
342 } catch (IOException ex) {
343 Logging.log(Logging.LEVEL_WARN, ex);
344 }
345 if (file == null)
346 return null;
347 Pair<String, InputStream> res = null;
348 try {
349 ZipFile zipFile = new ZipFile(file, StandardCharsets.UTF_8);
350 ZipEntry resentry = null;
351 Enumeration<? extends ZipEntry> entries = zipFile.entries();
352 while (entries.hasMoreElements()) {
353 ZipEntry entry = entries.nextElement();
354 // choose any file with correct extension. When more than one file, prefer the one which matches namepart
355 if (entry.getName().endsWith('.' + extension) && (resentry == null || entry.getName().indexOf(namepart) >= 0)) {
356 resentry = entry;
357 }
358 }
359 if (resentry != null) {
360 InputStream is = zipFile.getInputStream(resentry);
361 res = Pair.create(resentry.getName(), is);
362 } else {
363 Utils.close(zipFile);
364 }
365 } catch (IOException e) {
366 if (file.getName().endsWith(".zip")) {
367 Logging.log(Logging.LEVEL_WARN,
368 tr("Failed to open file with extension ''{2}'' and namepart ''{3}'' in zip file ''{0}''. Exception was: {1}",
369 file.getName(), e.toString(), extension, namepart), e);
370 }
371 }
372 return res;
373 }
374
375 /**
376 * Clear the cache for the given resource.
377 * This forces a fresh download.
378 * @param name the URL
379 */
380 public static void cleanup(String name) {
381 cleanup(name, null);
382 }
383
384 /**
385 * Clear the cache for the given resource.
386 * This forces a fresh download.
387 * @param name the URL
388 * @param destDir the destination directory (see {@link #setDestDir(java.lang.String)})
389 */
390 public static void cleanup(String name, String destDir) {
391 URL url;
392 try {
393 url = new URL(name);
394 if (!"file".equals(url.getProtocol())) {
395 String prefKey = getPrefKey(url, destDir);
396 List<String> localPath = new ArrayList<>(Config.getPref().getList(prefKey));
397 if (localPath.size() == 2) {
398 File lfile = new File(localPath.get(1));
399 if (lfile.exists()) {
400 Utils.deleteFile(lfile);
401 }
402 }
403 Config.getPref().putList(prefKey, null);
404 }
405 } catch (MalformedURLException e) {
406 Logging.warn(e);
407 }
408 }
409
410 /**
411 * Get preference key to store the location and age of the cached file.
412 * 2 resources that point to the same url, but that are to be stored in different
413 * directories will not share a cache file.
414 * @param url URL
415 * @param destDir destination directory
416 * @return Preference key
417 */
418 private static String getPrefKey(URL url, String destDir) {
419 StringBuilder prefKey = new StringBuilder("mirror.");
420 if (destDir != null) {
421 prefKey.append(destDir).append('.');
422 }
423 prefKey.append(url.toString().replaceAll("%<(.*)>", ""));
424 return prefKey.toString().replace("=", "_");
425 }
426
427 private File checkLocal(URL url) throws IOException {
428 String prefKey = getPrefKey(url, destDir);
429 String urlStr = url.toExternalForm();
430 if (parameter != null)
431 urlStr = urlStr.replaceAll("%<(.*)>", "");
432 long age = 0L;
433 long maxAgeMillis = TimeUnit.SECONDS.toMillis(maxAge);
434 Long ifModifiedSince = null;
435 File localFile = null;
436 List<String> localPathEntry = new ArrayList<>(Config.getPref().getList(prefKey));
437 boolean offline = false;
438 try {
439 checkOfflineAccess(urlStr);
440 } catch (OfflineAccessException e) {
441 Logging.trace(e);
442 offline = true;
443 }
444 if (localPathEntry.size() == 2) {
445 localFile = new File(localPathEntry.get(1));
446 if (!localFile.exists()) {
447 localFile = null;
448 } else {
449 if (maxAge == DEFAULT_MAXTIME
450 || maxAge <= 0 // arbitrary value <= 0 is deprecated
451 ) {
452 maxAgeMillis = TimeUnit.SECONDS.toMillis(Config.getPref().getLong("mirror.maxtime", TimeUnit.DAYS.toSeconds(7)));
453 }
454 age = System.currentTimeMillis() - Long.parseLong(localPathEntry.get(0));
455 if (offline || age < maxAgeMillis) {
456 return localFile;
457 }
458 if (cachingStrategy == CachingStrategy.IfModifiedSince) {
459 ifModifiedSince = Long.valueOf(localPathEntry.get(0));
460 }
461 }
462 }
463 if (destDir == null) {
464 destDir = Config.getDirs().getCacheDirectory(true).getPath();
465 }
466
467 File destDirFile = new File(destDir);
468 if (!destDirFile.exists()) {
469 Utils.mkDirs(destDirFile);
470 }
471
472 // No local file + offline => nothing to do
473 if (offline) {
474 return null;
475 }
476
477 if (parameter != null) {
478 String u = url.toExternalForm();
479 String uc;
480 if (parameter.isEmpty()) {
481 uc = u.replaceAll("%<(.*)>", "");
482 } else {
483 uc = u.replaceAll("%<(.*)>", "$1" + Utils.encodeUrl(parameter));
484 }
485 if (!uc.equals(u))
486 url = new URL(uc);
487 }
488
489 String a = urlStr.replaceAll("[^A-Za-z0-9_.-]", "_");
490 String localPath = "mirror_" + a;
491 localPath = truncatePath(destDir, localPath);
492 destDirFile = new File(destDir, localPath + ".tmp");
493 try {
494 activeConnection = HttpClient.create(url)
495 .setAccept(httpAccept)
496 .setIfModifiedSince(ifModifiedSince == null ? 0L : ifModifiedSince)
497 .setHeaders(httpHeaders);
498 if (fastFail) {
499 activeConnection.setReadTimeout(1000);
500 }
501 final HttpClient.Response con = activeConnection.connect();
502 if (ifModifiedSince != null && con.getResponseCode() == HttpURLConnection.HTTP_NOT_MODIFIED) {
503 Logging.debug("304 Not Modified ({0})", urlStr);
504 if (localFile == null)
505 throw new AssertionError();
506 Config.getPref().putList(prefKey,
507 Arrays.asList(Long.toString(System.currentTimeMillis()), localPathEntry.get(1)));
508 return localFile;
509 } else if (con.getResponseCode() == HttpURLConnection.HTTP_NOT_FOUND) {
510 throw new IOException(tr("The requested URL {0} was not found", urlStr));
511 }
512 try (InputStream is = con.getContent()) {
513 Files.copy(is, destDirFile.toPath(), StandardCopyOption.REPLACE_EXISTING);
514 }
515 activeConnection = null;
516 localFile = new File(destDir, localPath);
517 if (PlatformManager.getPlatform().rename(destDirFile, localFile)) {
518 Config.getPref().putList(prefKey,
519 Arrays.asList(Long.toString(System.currentTimeMillis()), localFile.toString()));
520 } else {
521 Logging.warn(tr("Failed to rename file {0} to {1}.",
522 destDirFile.getPath(), localFile.getPath()));
523 }
524 } catch (IOException e) {
525 if (age >= maxAgeMillis && age < maxAgeMillis*2) {
526 Logging.warn(tr("Failed to load {0}, use cached file and retry next time: {1}", urlStr, e));
527 return localFile;
528 } else {
529 throw e;
530 }
531 }
532
533 return localFile;
534 }
535
536 private static void checkOfflineAccess(String urlString) {
537 OnlineResource.JOSM_WEBSITE.checkOfflineAccess(urlString, Config.getUrls().getJOSMWebsite());
538 OnlineResource.OSM_API.checkOfflineAccess(urlString, OsmApi.getOsmApi().getServerUrl());
539 }
540
541 private static String truncatePath(String directory, String fileName) {
542 if (directory.length() + fileName.length() > 255) {
543 // Windows doesn't support paths longer than 260, leave 5 chars as safe buffer, 4 will be used by ".tmp"
544 // TODO: what about filename size on other systems? 255?
545 if (directory.length() > 191 && PlatformManager.isPlatformWindows()) {
546 // digest length + name prefix == 64
547 // 255 - 64 = 191
548 // TODO: use this check only on Windows?
549 throw new IllegalArgumentException("Path " + directory + " too long to cached files");
550 }
551
552 MessageDigest md;
553 try {
554 md = MessageDigest.getInstance("SHA-256");
555 md.update(fileName.getBytes(StandardCharsets.UTF_8));
556 String digest = String.format("%064x", new BigInteger(1, md.digest()));
557 return fileName.substring(0, Math.min(fileName.length(), 32)) + digest.substring(0, 32);
558 } catch (NoSuchAlgorithmException e) {
559 Logging.error(e);
560 // TODO: what better can we do here?
561 throw new IllegalArgumentException("Missing digest algorithm SHA-256", e);
562 }
563 }
564 return fileName;
565 }
566
567 /**
568 * Attempts to disconnect an URL connection.
569 * @see HttpClient#disconnect()
570 * @since 9411
571 */
572 @Override
573 public void close() {
574 if (activeConnection != null) {
575 activeConnection.disconnect();
576 }
577 }
578
579 /**
580 * Clears the cached file
581 * @throws IOException if any I/O error occurs
582 * @since 10993
583 */
584 public void clear() throws IOException {
585 URL url;
586 try {
587 url = new URL(name);
588 if ("file".equals(url.getProtocol())) {
589 return; // this is local file - do not delete it
590 }
591 } catch (MalformedURLException e) {
592 return; // if it's not a URL, then it still might be a local file - better not to delete
593 }
594 File f = getFile();
595 if (f != null && f.exists()) {
596 Utils.deleteFile(f);
597 }
598 }
599}
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