source: josm/trunk/src/org/openstreetmap/josm/io/CachedFile.java@ 13561

Last change on this file since 13561 was 13560, checked in by Don-vip, 6 years ago

see #14655 - javadoc
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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.ByteArrayOutputStream;
8import java.io.Closeable;
9import java.io.File;
10import java.io.IOException;
11import java.io.InputStream;
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.StandardCopyOption;
18import java.util.ArrayList;
19import java.util.Arrays;
20import java.util.Enumeration;
21import java.util.List;
22import java.util.Map;
23import java.util.concurrent.ConcurrentHashMap;
24import java.util.concurrent.TimeUnit;
25import java.util.zip.ZipEntry;
26import java.util.zip.ZipFile;
27
28import org.openstreetmap.josm.Main;
29import org.openstreetmap.josm.spi.preferences.Config;
30import org.openstreetmap.josm.tools.HttpClient;
31import org.openstreetmap.josm.tools.Logging;
32import org.openstreetmap.josm.tools.Pair;
33import org.openstreetmap.josm.tools.Utils;
34
35/**
36 * Downloads a file and caches it on disk in order to reduce network load.
37 *
38 * Supports URLs, local files, and a custom scheme (<code>resource:</code>) to get
39 * resources from the current *.jar file. (Local caching is only done for URLs.)
40 * <p>
41 * The mirrored file is only downloaded if it has been more than 7 days since
42 * last download. (Time can be configured.)
43 * <p>
44 * The file content is normally accessed with {@link #getInputStream()}, but
45 * you can also get the mirrored copy with {@link #getFile()}.
46 */
47public class CachedFile implements Closeable {
48
49 /**
50 * Caching strategy.
51 */
52 public enum CachingStrategy {
53 /**
54 * If cached file on disk is older than a certain time (7 days by default),
55 * consider the cache stale and try to download the file again.
56 */
57 MaxAge,
58 /**
59 * Similar to MaxAge, considers the cache stale when a certain age is
60 * exceeded. In addition, a If-Modified-Since HTTP header is added.
61 * When the server replies "304 Not Modified", this is considered the same
62 * as a full download.
63 */
64 IfModifiedSince
65 }
66
67 protected String name;
68 protected long maxAge;
69 protected String destDir;
70 protected String httpAccept;
71 protected CachingStrategy cachingStrategy;
72
73 private boolean fastFail;
74 private HttpClient activeConnection;
75 protected File cacheFile;
76 protected boolean initialized;
77 protected String parameter;
78
79 public static final long DEFAULT_MAXTIME = -1L;
80 public static final long DAYS = TimeUnit.DAYS.toSeconds(1); // factor to get caching time in days
81
82 private final Map<String, String> httpHeaders = new ConcurrentHashMap<>();
83
84 /**
85 * Constructs a CachedFile object from a given filename, URL or internal resource.
86 *
87 * @param name can be:<ul>
88 * <li>relative or absolute file name</li>
89 * <li>{@code file:///SOME/FILE} the same as above</li>
90 * <li>{@code http://...} a URL. It will be cached on disk.</li>
91 * <li>{@code resource://SOME/FILE} file from the classpath (usually in the current *.jar)</li>
92 * <li>{@code josmdir://SOME/FILE} file inside josm user data directory (since r7058)</li>
93 * <li>{@code josmplugindir://SOME/FILE} file inside josm plugin directory (since r7834)</li></ul>
94 */
95 public CachedFile(String name) {
96 this.name = name;
97 }
98
99 /**
100 * Set the name of the resource.
101 * @param name can be:<ul>
102 * <li>relative or absolute file name</li>
103 * <li>{@code file:///SOME/FILE} the same as above</li>
104 * <li>{@code http://...} a URL. It will be cached on disk.</li>
105 * <li>{@code resource://SOME/FILE} file from the classpath (usually in the current *.jar)</li>
106 * <li>{@code josmdir://SOME/FILE} file inside josm user data directory (since r7058)</li>
107 * <li>{@code josmplugindir://SOME/FILE} file inside josm plugin directory (since r7834)</li></ul>
108 * @return this object
109 */
110 public CachedFile setName(String name) {
111 this.name = name;
112 return this;
113 }
114
115 /**
116 * Set maximum age of cache file. Only applies to URLs.
117 * When this time has passed after the last download of the file, the
118 * cache is considered stale and a new download will be attempted.
119 * @param maxAge the maximum cache age in seconds
120 * @return this object
121 */
122 public CachedFile setMaxAge(long maxAge) {
123 this.maxAge = maxAge;
124 return this;
125 }
126
127 /**
128 * Set the destination directory for the cache file. Only applies to URLs.
129 * @param destDir the destination directory
130 * @return this object
131 */
132 public CachedFile setDestDir(String destDir) {
133 this.destDir = destDir;
134 return this;
135 }
136
137 /**
138 * Set the accepted MIME types sent in the HTTP Accept header. Only applies to URLs.
139 * @param httpAccept the accepted MIME types
140 * @return this object
141 */
142 public CachedFile setHttpAccept(String httpAccept) {
143 this.httpAccept = httpAccept;
144 return this;
145 }
146
147 /**
148 * Set the caching strategy. Only applies to URLs.
149 * @param cachingStrategy caching strategy
150 * @return this object
151 */
152 public CachedFile setCachingStrategy(CachingStrategy cachingStrategy) {
153 this.cachingStrategy = cachingStrategy;
154 return this;
155 }
156
157 /**
158 * Sets the http headers. Only applies to URL pointing to http or https resources
159 * @param headers that should be sent together with request
160 * @return this object
161 */
162 public CachedFile setHttpHeaders(Map<String, String> headers) {
163 this.httpHeaders.putAll(headers);
164 return this;
165 }
166
167 /**
168 * Sets whether opening HTTP connections should fail fast, i.e., whether a
169 * {@link HttpClient#setConnectTimeout(int) low connect timeout} should be used.
170 * @param fastFail whether opening HTTP connections should fail fast
171 */
172 public void setFastFail(boolean fastFail) {
173 this.fastFail = fastFail;
174 }
175
176 /**
177 * Sets additional URL parameter (used e.g. for maps)
178 * @param parameter the URL parameter
179 * @since 13536
180 */
181 public void setParam(String parameter) {
182 this.parameter = parameter;
183 }
184
185 public String getName() {
186 if (parameter != null)
187 return name.replaceAll("%<(.*)>", "");
188 return name;
189 }
190
191 /**
192 * Returns maximum age of cache file. Only applies to URLs.
193 * When this time has passed after the last download of the file, the
194 * cache is considered stale and a new download will be attempted.
195 * @return the maximum cache age in seconds
196 */
197 public long getMaxAge() {
198 return maxAge;
199 }
200
201 public String getDestDir() {
202 return destDir;
203 }
204
205 public String getHttpAccept() {
206 return httpAccept;
207 }
208
209 public CachingStrategy getCachingStrategy() {
210 return cachingStrategy;
211 }
212
213 /**
214 * Get InputStream to the requested resource.
215 * @return the InputStream
216 * @throws IOException when the resource with the given name could not be retrieved
217 */
218 public InputStream getInputStream() throws IOException {
219 File file = getFile();
220 if (file == null) {
221 if (name != null && name.startsWith("resource://")) {
222 InputStream is = getClass().getResourceAsStream(
223 name.substring("resource:/".length()));
224 if (is == null)
225 throw new IOException(tr("Failed to open input stream for resource ''{0}''", name));
226 return is;
227 } else {
228 throw new IOException("No file found for: "+name);
229 }
230 }
231 return Files.newInputStream(file.toPath());
232 }
233
234 /**
235 * Get the full content of the requested resource as a byte array.
236 * @return the full content of the requested resource as byte array
237 * @throws IOException in case of an I/O error
238 */
239 public byte[] getByteContent() throws IOException {
240 try (InputStream is = getInputStream()) {
241 ByteArrayOutputStream buffer = new ByteArrayOutputStream();
242 int nRead;
243 byte[] data = new byte[8192];
244 while ((nRead = is.read(data, 0, data.length)) != -1) {
245 buffer.write(data, 0, nRead);
246 }
247 buffer.flush();
248 return buffer.toByteArray();
249 }
250 }
251
252 /**
253 * Returns {@link #getInputStream()} wrapped in a buffered reader.
254 * <p>
255 * Detects Unicode charset in use utilizing {@link UTFInputStreamReader}.
256 *
257 * @return buffered reader
258 * @throws IOException if any I/O error occurs
259 * @since 9411
260 */
261 public BufferedReader getContentReader() throws IOException {
262 return new BufferedReader(UTFInputStreamReader.create(getInputStream()));
263 }
264
265 /**
266 * Get local file for the requested resource.
267 * @return The local cache file for URLs. If the resource is a local file,
268 * returns just that file.
269 * @throws IOException when the resource with the given name could not be retrieved
270 */
271 public synchronized File getFile() throws IOException {
272 if (initialized)
273 return cacheFile;
274 initialized = true;
275 URL url;
276 try {
277 url = new URL(name);
278 if ("file".equals(url.getProtocol())) {
279 cacheFile = new File(name.substring("file:/".length() - 1));
280 if (!cacheFile.exists()) {
281 cacheFile = new File(name.substring("file://".length() - 1));
282 }
283 } else {
284 cacheFile = checkLocal(url);
285 }
286 } catch (MalformedURLException e) {
287 if (name == null || name.startsWith("resource://")) {
288 return null;
289 } else if (name.startsWith("josmdir://")) {
290 cacheFile = new File(Config.getDirs().getUserDataDirectory(false), name.substring("josmdir://".length()));
291 } else if (name.startsWith("josmplugindir://")) {
292 cacheFile = new File(Main.pref.getPluginsDirectory(), name.substring("josmplugindir://".length()));
293 } else {
294 cacheFile = new File(name);
295 }
296 }
297 if (cacheFile == null)
298 throw new IOException("Unable to get cache file for "+getName());
299 return cacheFile;
300 }
301
302 /**
303 * Looks for a certain entry inside a zip file and returns the entry path.
304 *
305 * Replies a file in the top level directory of the ZIP file which has an
306 * extension <code>extension</code>. If more than one files have this
307 * extension, the last file whose name includes <code>namepart</code>
308 * is opened.
309 *
310 * @param extension the extension of the file we're looking for
311 * @param namepart the name part
312 * @return The zip entry path of the matching file. <code>null</code> if this cached file
313 * doesn't represent a zip file or if there was no matching
314 * file in the ZIP file.
315 */
316 public String findZipEntryPath(String extension, String namepart) {
317 Pair<String, InputStream> ze = findZipEntryImpl(extension, namepart);
318 if (ze == null) return null;
319 return ze.a;
320 }
321
322 /**
323 * Like {@link #findZipEntryPath}, but returns the corresponding InputStream.
324 * @param extension the extension of the file we're looking for
325 * @param namepart the name part
326 * @return InputStream to the matching file. <code>null</code> if this cached file
327 * doesn't represent a zip file or if there was no matching
328 * file in the ZIP file.
329 * @since 6148
330 */
331 public InputStream findZipEntryInputStream(String extension, String namepart) {
332 Pair<String, InputStream> ze = findZipEntryImpl(extension, namepart);
333 if (ze == null) return null;
334 return ze.b;
335 }
336
337 private Pair<String, InputStream> findZipEntryImpl(String extension, String namepart) {
338 File file = null;
339 try {
340 file = getFile();
341 } catch (IOException ex) {
342 Logging.log(Logging.LEVEL_WARN, ex);
343 }
344 if (file == null)
345 return null;
346 Pair<String, InputStream> res = null;
347 try {
348 ZipFile zipFile = new ZipFile(file, StandardCharsets.UTF_8);
349 ZipEntry resentry = null;
350 Enumeration<? extends ZipEntry> entries = zipFile.entries();
351 while (entries.hasMoreElements()) {
352 ZipEntry entry = entries.nextElement();
353 // choose any file with correct extension. When more than one file, prefer the one which matches namepart
354 if (entry.getName().endsWith('.' + extension) && (resentry == null || entry.getName().indexOf(namepart) >= 0)) {
355 resentry = entry;
356 }
357 }
358 if (resentry != null) {
359 InputStream is = zipFile.getInputStream(resentry);
360 res = Pair.create(resentry.getName(), is);
361 } else {
362 Utils.close(zipFile);
363 }
364 } catch (IOException e) {
365 if (file.getName().endsWith(".zip")) {
366 Logging.log(Logging.LEVEL_WARN,
367 tr("Failed to open file with extension ''{2}'' and namepart ''{3}'' in zip file ''{0}''. Exception was: {1}",
368 file.getName(), e.toString(), extension, namepart), e);
369 }
370 }
371 return res;
372 }
373
374 /**
375 * Clear the cache for the given resource.
376 * This forces a fresh download.
377 * @param name the URL
378 */
379 public static void cleanup(String name) {
380 cleanup(name, null);
381 }
382
383 /**
384 * Clear the cache for the given resource.
385 * This forces a fresh download.
386 * @param name the URL
387 * @param destDir the destination directory (see {@link #setDestDir(java.lang.String)})
388 */
389 public static void cleanup(String name, String destDir) {
390 URL url;
391 try {
392 url = new URL(name);
393 if (!"file".equals(url.getProtocol())) {
394 String prefKey = getPrefKey(url, destDir, null);
395 List<String> localPath = new ArrayList<>(Config.getPref().getList(prefKey));
396 if (localPath.size() == 2) {
397 File lfile = new File(localPath.get(1));
398 if (lfile.exists()) {
399 Utils.deleteFile(lfile);
400 }
401 }
402 Config.getPref().putList(prefKey, null);
403 }
404 } catch (MalformedURLException e) {
405 Logging.warn(e);
406 }
407 }
408
409 /**
410 * Get preference key to store the location and age of the cached file.
411 * 2 resources that point to the same url, but that are to be stored in different
412 * directories will not share a cache file.
413 * @param url URL
414 * @param destDir destination directory
415 * @param parameter additional URL parameter (used e.g. for maps)
416 * @return Preference key
417 */
418 private static String getPrefKey(URL url, String destDir, String parameter) {
419 StringBuilder prefKey = new StringBuilder("mirror.");
420 if (destDir != null) {
421 prefKey.append(destDir).append('.');
422 }
423 if (parameter != null) {
424 prefKey.append(url.toString().replaceAll("%<(.*)>", ""));
425 } else {
426 prefKey.append(url.toString());
427 }
428 return prefKey.toString().replaceAll("=", "_");
429 }
430
431 private File checkLocal(URL url) throws IOException {
432 String prefKey = getPrefKey(url, destDir, parameter);
433 String urlStr = url.toExternalForm();
434 if (parameter != null)
435 urlStr = urlStr.replaceAll("%<(.*)>", "");
436 long age = 0L;
437 long maxAgeMillis = maxAge;
438 Long ifModifiedSince = null;
439 File localFile = null;
440 List<String> localPathEntry = new ArrayList<>(Config.getPref().getList(prefKey));
441 boolean offline = false;
442 try {
443 checkOfflineAccess(urlStr);
444 } catch (OfflineAccessException e) {
445 Logging.trace(e);
446 offline = true;
447 }
448 if (localPathEntry.size() == 2) {
449 localFile = new File(localPathEntry.get(1));
450 if (!localFile.exists()) {
451 localFile = null;
452 } else {
453 if (maxAge == DEFAULT_MAXTIME
454 || maxAge <= 0 // arbitrary value <= 0 is deprecated
455 ) {
456 maxAgeMillis = TimeUnit.SECONDS.toMillis(Config.getPref().getLong("mirror.maxtime", TimeUnit.DAYS.toSeconds(7)));
457 }
458 age = System.currentTimeMillis() - Long.parseLong(localPathEntry.get(0));
459 if (offline || age < maxAgeMillis) {
460 return localFile;
461 }
462 if (cachingStrategy == CachingStrategy.IfModifiedSince) {
463 ifModifiedSince = Long.valueOf(localPathEntry.get(0));
464 }
465 }
466 }
467 if (destDir == null) {
468 destDir = Config.getDirs().getCacheDirectory(true).getPath();
469 }
470
471 File destDirFile = new File(destDir);
472 if (!destDirFile.exists()) {
473 Utils.mkDirs(destDirFile);
474 }
475
476 // No local file + offline => nothing to do
477 if (offline) {
478 return null;
479 }
480
481 if (parameter != null) {
482 String u = url.toExternalForm();
483 String uc;
484 if (parameter.isEmpty()) {
485 uc = u.replaceAll("%<(.*)>", "");
486 } else {
487 uc = u.replaceAll("%<(.*)>", "$1"+parameter);
488 }
489 if (!uc.equals(u))
490 url = new URL(uc);
491 }
492
493 String a = urlStr.replaceAll("[^A-Za-z0-9_.-]", "_");
494 String localPath = "mirror_" + a;
495 destDirFile = new File(destDir, localPath + ".tmp");
496 try {
497 activeConnection = HttpClient.create(url)
498 .setAccept(httpAccept)
499 .setIfModifiedSince(ifModifiedSince == null ? 0L : ifModifiedSince)
500 .setHeaders(httpHeaders);
501 if (fastFail) {
502 activeConnection.setReadTimeout(1000);
503 }
504 final HttpClient.Response con = activeConnection.connect();
505 if (ifModifiedSince != null && con.getResponseCode() == HttpURLConnection.HTTP_NOT_MODIFIED) {
506 Logging.debug("304 Not Modified ({0})", urlStr);
507 if (localFile == null)
508 throw new AssertionError();
509 Config.getPref().putList(prefKey,
510 Arrays.asList(Long.toString(System.currentTimeMillis()), localPathEntry.get(1)));
511 return localFile;
512 } else if (con.getResponseCode() == HttpURLConnection.HTTP_NOT_FOUND) {
513 throw new IOException(tr("The requested URL {0} was not found", urlStr));
514 }
515 try (InputStream is = con.getContent()) {
516 Files.copy(is, destDirFile.toPath(), StandardCopyOption.REPLACE_EXISTING);
517 }
518 activeConnection = null;
519 localFile = new File(destDir, localPath);
520 if (Main.platform.rename(destDirFile, localFile)) {
521 Config.getPref().putList(prefKey,
522 Arrays.asList(Long.toString(System.currentTimeMillis()), localFile.toString()));
523 } else {
524 Logging.warn(tr("Failed to rename file {0} to {1}.",
525 destDirFile.getPath(), localFile.getPath()));
526 }
527 } catch (IOException e) {
528 if (age >= maxAgeMillis && age < maxAgeMillis*2) {
529 Logging.warn(tr("Failed to load {0}, use cached file and retry next time: {1}", urlStr, e));
530 return localFile;
531 } else {
532 throw e;
533 }
534 }
535
536 return localFile;
537 }
538
539 private static void checkOfflineAccess(String urlString) {
540 OnlineResource.JOSM_WEBSITE.checkOfflineAccess(urlString, Main.getJOSMWebsite());
541 OnlineResource.OSM_API.checkOfflineAccess(urlString, OsmApi.getOsmApi().getServerUrl());
542 }
543
544 /**
545 * Attempts to disconnect an URL connection.
546 * @see HttpClient#disconnect()
547 * @since 9411
548 */
549 @Override
550 public void close() {
551 if (activeConnection != null) {
552 activeConnection.disconnect();
553 }
554 }
555
556 /**
557 * Clears the cached file
558 * @throws IOException if any I/O error occurs
559 * @since 10993
560 */
561 public void clear() throws IOException {
562 URL url;
563 try {
564 url = new URL(name);
565 if ("file".equals(url.getProtocol())) {
566 return; // this is local file - do not delete it
567 }
568 } catch (MalformedURLException e) {
569 return; // if it's not a URL, then it still might be a local file - better not to delete
570 }
571 File f = getFile();
572 if (f != null && f.exists()) {
573 Utils.deleteFile(f);
574 }
575 }
576}
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