source: josm/trunk/src/org/openstreetmap/josm/io/CachedFile.java@ 9870

Last change on this file since 9870 was 9645, checked in by Don-vip, 8 years ago

fix findbugs issue RV_RETURN_VALUE_IGNORED_BAD_PRACTICE for java.io.File.mkdirs
  • Property svn:eol-style set to native
File size: 17.9 KB
Line 
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.BufferedInputStream;
7import java.io.BufferedReader;
8import java.io.Closeable;
9import java.io.File;
10import java.io.FileInputStream;
11import java.io.IOException;
12import java.io.InputStream;
13import java.net.HttpURLConnection;
14import java.net.MalformedURLException;
15import java.net.URL;
16import java.nio.charset.StandardCharsets;
17import java.nio.file.Files;
18import java.nio.file.StandardCopyOption;
19import java.util.ArrayList;
20import java.util.Arrays;
21import java.util.Enumeration;
22import java.util.List;
23import java.util.Map;
24import java.util.concurrent.ConcurrentHashMap;
25import java.util.zip.ZipEntry;
26import java.util.zip.ZipFile;
27
28import org.openstreetmap.josm.Main;
29import org.openstreetmap.josm.tools.HttpClient;
30import org.openstreetmap.josm.tools.Pair;
31import org.openstreetmap.josm.tools.Utils;
32
33/**
34 * Downloads a file and caches it on disk in order to reduce network load.
35 *
36 * Supports URLs, local files, and a custom scheme (<code>resource:</code>) to get
37 * resources from the current *.jar file. (Local caching is only done for URLs.)
38 * <p>
39 * The mirrored file is only downloaded if it has been more than 7 days since
40 * last download. (Time can be configured.)
41 * <p>
42 * The file content is normally accessed with {@link #getInputStream()}, but
43 * you can also get the mirrored copy with {@link #getFile()}.
44 */
45public class CachedFile implements Closeable {
46
47 /**
48 * Caching strategy.
49 */
50 public enum CachingStrategy {
51 /**
52 * If cached file on disk is older than a certain time (7 days by default),
53 * consider the cache stale and try to download the file again.
54 */
55 MaxAge,
56 /**
57 * Similar to MaxAge, considers the cache stale when a certain age is
58 * exceeded. In addition, a If-Modified-Since HTTP header is added.
59 * When the server replies "304 Not Modified", this is considered the same
60 * as a full download.
61 */
62 IfModifiedSince
63 }
64
65 protected String name;
66 protected long maxAge;
67 protected String destDir;
68 protected String httpAccept;
69 protected CachingStrategy cachingStrategy;
70
71 private transient boolean fastFail;
72 private transient HttpClient activeConnection;
73 protected File cacheFile;
74 protected boolean initialized;
75
76 public static final long DEFAULT_MAXTIME = -1L;
77 public static final long DAYS = 24*60*60; // factor to get caching time in days
78
79 private final Map<String, String> httpHeaders = new ConcurrentHashMap<>();
80
81 /**
82 * Constructs a CachedFile object from a given filename, URL or internal resource.
83 *
84 * @param name can be:<ul>
85 * <li>relative or absolute file name</li>
86 * <li>{@code file:///SOME/FILE} the same as above</li>
87 * <li>{@code http://...} a URL. It will be cached on disk.</li>
88 * <li>{@code resource://SOME/FILE} file from the classpath (usually in the current *.jar)</li>
89 * <li>{@code josmdir://SOME/FILE} file inside josm user data directory (since r7058)</li>
90 * <li>{@code josmplugindir://SOME/FILE} file inside josm plugin directory (since r7834)</li></ul>
91 */
92 public CachedFile(String name) {
93 this.name = name;
94 }
95
96 /**
97 * Set the name of the resource.
98 * @param name can be:<ul>
99 * <li>relative or absolute file name</li>
100 * <li>{@code file:///SOME/FILE} the same as above</li>
101 * <li>{@code http://...} a URL. It will be cached on disk.</li>
102 * <li>{@code resource://SOME/FILE} file from the classpath (usually in the current *.jar)</li>
103 * <li>{@code josmdir://SOME/FILE} file inside josm user data directory (since r7058)</li>
104 * <li>{@code josmplugindir://SOME/FILE} file inside josm plugin directory (since r7834)</li></ul>
105 * @return this object
106 */
107 public CachedFile setName(String name) {
108 this.name = name;
109 return this;
110 }
111
112 /**
113 * Set maximum age of cache file. Only applies to URLs.
114 * When this time has passed after the last download of the file, the
115 * cache is considered stale and a new download will be attempted.
116 * @param maxAge the maximum cache age in seconds
117 * @return this object
118 */
119 public CachedFile setMaxAge(long maxAge) {
120 this.maxAge = maxAge;
121 return this;
122 }
123
124 /**
125 * Set the destination directory for the cache file. Only applies to URLs.
126 * @param destDir the destination directory
127 * @return this object
128 */
129 public CachedFile setDestDir(String destDir) {
130 this.destDir = destDir;
131 return this;
132 }
133
134 /**
135 * Set the accepted MIME types sent in the HTTP Accept header. Only applies to URLs.
136 * @param httpAccept the accepted MIME types
137 * @return this object
138 */
139 public CachedFile setHttpAccept(String httpAccept) {
140 this.httpAccept = httpAccept;
141 return this;
142 }
143
144 /**
145 * Set the caching strategy. Only applies to URLs.
146 * @param cachingStrategy caching strategy
147 * @return this object
148 */
149 public CachedFile setCachingStrategy(CachingStrategy cachingStrategy) {
150 this.cachingStrategy = cachingStrategy;
151 return this;
152 }
153
154 /**
155 * Sets the http headers. Only applies to URL pointing to http or https resources
156 * @param headers that should be sent together with request
157 * @return this object
158 */
159 public CachedFile setHttpHeaders(Map<String, String> headers) {
160 this.httpHeaders.putAll(headers);
161 return this;
162 }
163
164 /**
165 * Sets whether opening HTTP connections should fail fast, i.e., whether a
166 * {@link HttpClient#setConnectTimeout(int) low connect timeout} should be used.
167 * @param fastFail whether opening HTTP connections should fail fast
168 */
169 public void setFastFail(boolean fastFail) {
170 this.fastFail = fastFail;
171 }
172
173 public String getName() {
174 return name;
175 }
176
177 public long getMaxAge() {
178 return maxAge;
179 }
180
181 public String getDestDir() {
182 return destDir;
183 }
184
185 public String getHttpAccept() {
186 return httpAccept;
187 }
188
189 public CachingStrategy getCachingStrategy() {
190 return cachingStrategy;
191 }
192
193 /**
194 * Get InputStream to the requested resource.
195 * @return the InputStream
196 * @throws IOException when the resource with the given name could not be retrieved
197 */
198 public InputStream getInputStream() throws IOException {
199 File file = getFile();
200 if (file == null) {
201 if (name.startsWith("resource://")) {
202 InputStream is = getClass().getResourceAsStream(
203 name.substring("resource:/".length()));
204 if (is == null)
205 throw new IOException(tr("Failed to open input stream for resource ''{0}''", name));
206 return is;
207 } else {
208 throw new IOException("No file found for: "+name);
209 }
210 }
211 return new FileInputStream(file);
212 }
213
214 /**
215 * Returns {@link #getInputStream()} wrapped in a buffered reader.
216 * <p>
217 * Detects Unicode charset in use utilizing {@link UTFInputStreamReader}.
218 *
219 * @return buffered reader
220 * @throws IOException if any I/O error occurs
221 * @since 9411
222 */
223 public BufferedReader getContentReader() throws IOException {
224 return new BufferedReader(UTFInputStreamReader.create(getInputStream()));
225 }
226
227 /**
228 * Get local file for the requested resource.
229 * @return The local cache file for URLs. If the resource is a local file,
230 * returns just that file.
231 * @throws IOException when the resource with the given name could not be retrieved
232 */
233 public synchronized File getFile() throws IOException {
234 if (initialized)
235 return cacheFile;
236 initialized = true;
237 URL url;
238 try {
239 url = new URL(name);
240 if ("file".equals(url.getProtocol())) {
241 cacheFile = new File(name.substring("file:/".length() - 1));
242 if (!cacheFile.exists()) {
243 cacheFile = new File(name.substring("file://".length() - 1));
244 }
245 } else {
246 cacheFile = checkLocal(url);
247 }
248 } catch (MalformedURLException e) {
249 if (name.startsWith("resource://")) {
250 return null;
251 } else if (name.startsWith("josmdir://")) {
252 cacheFile = new File(Main.pref.getUserDataDirectory(), name.substring("josmdir://".length()));
253 } else if (name.startsWith("josmplugindir://")) {
254 cacheFile = new File(Main.pref.getPluginsDirectory(), name.substring("josmplugindir://".length()));
255 } else {
256 cacheFile = new File(name);
257 }
258 }
259 if (cacheFile == null)
260 throw new IOException("Unable to get cache file for "+name);
261 return cacheFile;
262 }
263
264 /**
265 * Looks for a certain entry inside a zip file and returns the entry path.
266 *
267 * Replies a file in the top level directory of the ZIP file which has an
268 * extension <code>extension</code>. If more than one files have this
269 * extension, the last file whose name includes <code>namepart</code>
270 * is opened.
271 *
272 * @param extension the extension of the file we're looking for
273 * @param namepart the name part
274 * @return The zip entry path of the matching file. Null if this cached file
275 * doesn't represent a zip file or if there was no matching
276 * file in the ZIP file.
277 */
278 public String findZipEntryPath(String extension, String namepart) {
279 Pair<String, InputStream> ze = findZipEntryImpl(extension, namepart);
280 if (ze == null) return null;
281 return ze.a;
282 }
283
284 /**
285 * Like {@link #findZipEntryPath}, but returns the corresponding InputStream.
286 * @param extension the extension of the file we're looking for
287 * @param namepart the name part
288 * @return InputStream to the matching file. Null if this cached file
289 * doesn't represent a zip file or if there was no matching
290 * file in the ZIP file.
291 * @since 6148
292 */
293 public InputStream findZipEntryInputStream(String extension, String namepart) {
294 Pair<String, InputStream> ze = findZipEntryImpl(extension, namepart);
295 if (ze == null) return null;
296 return ze.b;
297 }
298
299 private Pair<String, InputStream> findZipEntryImpl(String extension, String namepart) {
300 File file = null;
301 try {
302 file = getFile();
303 } catch (IOException ex) {
304 Main.warn(ex, false);
305 }
306 if (file == null)
307 return null;
308 Pair<String, InputStream> res = null;
309 try {
310 ZipFile zipFile = new ZipFile(file, StandardCharsets.UTF_8);
311 ZipEntry resentry = null;
312 Enumeration<? extends ZipEntry> entries = zipFile.entries();
313 while (entries.hasMoreElements()) {
314 ZipEntry entry = entries.nextElement();
315 if (entry.getName().endsWith('.' + extension)) {
316 /* choose any file with correct extension. When more than
317 one file, prefer the one which matches namepart */
318 if (resentry == null || entry.getName().indexOf(namepart) >= 0) {
319 resentry = entry;
320 }
321 }
322 }
323 if (resentry != null) {
324 InputStream is = zipFile.getInputStream(resentry);
325 res = Pair.create(resentry.getName(), is);
326 } else {
327 Utils.close(zipFile);
328 }
329 } catch (Exception e) {
330 if (file.getName().endsWith(".zip")) {
331 Main.warn(tr("Failed to open file with extension ''{2}'' and namepart ''{3}'' in zip file ''{0}''. Exception was: {1}",
332 file.getName(), e.toString(), extension, namepart));
333 }
334 }
335 return res;
336 }
337
338 /**
339 * Clear the cache for the given resource.
340 * This forces a fresh download.
341 * @param name the URL
342 */
343 public static void cleanup(String name) {
344 cleanup(name, null);
345 }
346
347 /**
348 * Clear the cache for the given resource.
349 * This forces a fresh download.
350 * @param name the URL
351 * @param destDir the destination directory (see {@link #setDestDir(java.lang.String)})
352 */
353 public static void cleanup(String name, String destDir) {
354 URL url;
355 try {
356 url = new URL(name);
357 if (!"file".equals(url.getProtocol())) {
358 String prefKey = getPrefKey(url, destDir);
359 List<String> localPath = new ArrayList<>(Main.pref.getCollection(prefKey));
360 if (localPath.size() == 2) {
361 File lfile = new File(localPath.get(1));
362 if (lfile.exists()) {
363 Utils.deleteFile(lfile);
364 }
365 }
366 Main.pref.putCollection(prefKey, null);
367 }
368 } catch (MalformedURLException e) {
369 Main.warn(e);
370 }
371 }
372
373 /**
374 * Get preference key to store the location and age of the cached file.
375 * 2 resources that point to the same url, but that are to be stored in different
376 * directories will not share a cache file.
377 * @param url URL
378 * @param destDir destination directory
379 * @return Preference key
380 */
381 private static String getPrefKey(URL url, String destDir) {
382 StringBuilder prefKey = new StringBuilder("mirror.");
383 if (destDir != null) {
384 prefKey.append(destDir).append('.');
385 }
386 prefKey.append(url.toString());
387 return prefKey.toString().replaceAll("=", "_");
388 }
389
390 private File checkLocal(URL url) throws IOException {
391 String prefKey = getPrefKey(url, destDir);
392 String urlStr = url.toExternalForm();
393 long age = 0L;
394 long lMaxAge = maxAge;
395 Long ifModifiedSince = null;
396 File localFile = null;
397 List<String> localPathEntry = new ArrayList<>(Main.pref.getCollection(prefKey));
398 boolean offline = false;
399 try {
400 checkOfflineAccess(urlStr);
401 } catch (OfflineAccessException e) {
402 offline = true;
403 }
404 if (localPathEntry.size() == 2) {
405 localFile = new File(localPathEntry.get(1));
406 if (!localFile.exists()) {
407 localFile = null;
408 } else {
409 if (maxAge == DEFAULT_MAXTIME
410 || maxAge <= 0 // arbitrary value <= 0 is deprecated
411 ) {
412 lMaxAge = Main.pref.getInteger("mirror.maxtime", 7*24*60*60); // one week
413 }
414 age = System.currentTimeMillis() - Long.parseLong(localPathEntry.get(0));
415 if (offline || age < lMaxAge*1000) {
416 return localFile;
417 }
418 if (cachingStrategy == CachingStrategy.IfModifiedSince) {
419 ifModifiedSince = Long.valueOf(localPathEntry.get(0));
420 }
421 }
422 }
423 if (destDir == null) {
424 destDir = Main.pref.getCacheDirectory().getPath();
425 }
426
427 File destDirFile = new File(destDir);
428 if (!destDirFile.exists()) {
429 Utils.mkDirs(destDirFile);
430 }
431
432 // No local file + offline => nothing to do
433 if (offline) {
434 return null;
435 }
436
437 String a = urlStr.replaceAll("[^A-Za-z0-9_.-]", "_");
438 String localPath = "mirror_" + a;
439 destDirFile = new File(destDir, localPath + ".tmp");
440 try {
441 activeConnection = HttpClient.create(url)
442 .setAccept(httpAccept)
443 .setIfModifiedSince(ifModifiedSince == null ? 0L : ifModifiedSince)
444 .setHeaders(httpHeaders);
445 if (fastFail) {
446 activeConnection.setReadTimeout(1000);
447 }
448 final HttpClient.Response con = activeConnection.connect();
449 if (ifModifiedSince != null && con.getResponseCode() == HttpURLConnection.HTTP_NOT_MODIFIED) {
450 if (Main.isDebugEnabled()) {
451 Main.debug("304 Not Modified ("+urlStr+')');
452 }
453 if (localFile == null)
454 throw new AssertionError();
455 Main.pref.putCollection(prefKey,
456 Arrays.asList(Long.toString(System.currentTimeMillis()), localPathEntry.get(1)));
457 return localFile;
458 }
459 try (InputStream bis = new BufferedInputStream(con.getContent())) {
460 Files.copy(bis, destDirFile.toPath(), StandardCopyOption.REPLACE_EXISTING);
461 }
462 activeConnection = null;
463 localFile = new File(destDir, localPath);
464 if (Main.platform.rename(destDirFile, localFile)) {
465 Main.pref.putCollection(prefKey,
466 Arrays.asList(Long.toString(System.currentTimeMillis()), localFile.toString()));
467 } else {
468 Main.warn(tr("Failed to rename file {0} to {1}.",
469 destDirFile.getPath(), localFile.getPath()));
470 }
471 } catch (IOException e) {
472 if (age >= lMaxAge*1000 && age < lMaxAge*1000*2) {
473 Main.warn(tr("Failed to load {0}, use cached file and retry next time: {1}", urlStr, e));
474 return localFile;
475 } else {
476 throw e;
477 }
478 }
479
480 return localFile;
481 }
482
483 private static void checkOfflineAccess(String urlString) {
484 OnlineResource.JOSM_WEBSITE.checkOfflineAccess(urlString, Main.getJOSMWebsite());
485 OnlineResource.OSM_API.checkOfflineAccess(urlString, OsmApi.getOsmApi().getServerUrl());
486 }
487
488 /**
489 * Attempts to disconnect an URL connection.
490 * @see HttpClient#disconnect()
491 * @since 9411
492 */
493 @Override
494 public void close() {
495 if (activeConnection != null) {
496 activeConnection.disconnect();
497 }
498 }
499}
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