source: josm/trunk/src/org/openstreetmap/josm/io/CachedFile.java@ 9308

Last change on this file since 9308 was 9296, checked in by Don-vip, 8 years ago

fix #12249 - Fix Findbugs warnings "Exceptional return value of java.io.File.delete() ignored"
  • Property svn:eol-style set to native
File size: 16.6 KB
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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.BufferedInputStream;
7import java.io.File;
8import java.io.FileInputStream;
9import java.io.IOException;
10import java.io.InputStream;
11import java.net.HttpURLConnection;
12import java.net.MalformedURLException;
13import java.net.URL;
14import java.nio.charset.StandardCharsets;
15import java.nio.file.Files;
16import java.nio.file.StandardCopyOption;
17import java.util.ArrayList;
18import java.util.Arrays;
19import java.util.Enumeration;
20import java.util.List;
21import java.util.Map;
22import java.util.concurrent.ConcurrentHashMap;
23import java.util.zip.ZipEntry;
24import java.util.zip.ZipFile;
25
26import org.openstreetmap.josm.Main;
27import org.openstreetmap.josm.tools.HttpClient;
28import org.openstreetmap.josm.tools.Pair;
29import org.openstreetmap.josm.tools.Utils;
30
31/**
32 * Downloads a file and caches it on disk in order to reduce network load.
33 *
34 * Supports URLs, local files, and a custom scheme (<code>resource:</code>) to get
35 * resources from the current *.jar file. (Local caching is only done for URLs.)
36 * <p>
37 * The mirrored file is only downloaded if it has been more than 7 days since
38 * last download. (Time can be configured.)
39 * <p>
40 * The file content is normally accessed with {@link #getInputStream()}, but
41 * you can also get the mirrored copy with {@link #getFile()}.
42 */
43public class CachedFile {
44
45 /**
46 * Caching strategy.
47 */
48 public enum CachingStrategy {
49 /**
50 * If cached file on disk is older than a certain time (7 days by default),
51 * consider the cache stale and try to download the file again.
52 */
53 MaxAge,
54 /**
55 * Similar to MaxAge, considers the cache stale when a certain age is
56 * exceeded. In addition, a If-Modified-Since HTTP header is added.
57 * When the server replies "304 Not Modified", this is considered the same
58 * as a full download.
59 */
60 IfModifiedSince
61 }
62
63 protected String name;
64 protected long maxAge;
65 protected String destDir;
66 protected String httpAccept;
67 protected CachingStrategy cachingStrategy;
68
69 protected File cacheFile;
70 protected boolean initialized;
71
72 public static final long DEFAULT_MAXTIME = -1L;
73 public static final long DAYS = 24*60*60; // factor to get caching time in days
74
75 private final Map<String, String> httpHeaders = new ConcurrentHashMap<>();
76
77 /**
78 * Constructs a CachedFile object from a given filename, URL or internal resource.
79 *
80 * @param name can be:<ul>
81 * <li>relative or absolute file name</li>
82 * <li>{@code file:///SOME/FILE} the same as above</li>
83 * <li>{@code http://...} a URL. It will be cached on disk.</li>
84 * <li>{@code resource://SOME/FILE} file from the classpath (usually in the current *.jar)</li>
85 * <li>{@code josmdir://SOME/FILE} file inside josm user data directory (since r7058)</li>
86 * <li>{@code josmplugindir://SOME/FILE} file inside josm plugin directory (since r7834)</li></ul>
87 */
88 public CachedFile(String name) {
89 this.name = name;
90 }
91
92 /**
93 * Set the name of the resource.
94 * @param name can be:<ul>
95 * <li>relative or absolute file name</li>
96 * <li>{@code file:///SOME/FILE} the same as above</li>
97 * <li>{@code http://...} a URL. It will be cached on disk.</li>
98 * <li>{@code resource://SOME/FILE} file from the classpath (usually in the current *.jar)</li>
99 * <li>{@code josmdir://SOME/FILE} file inside josm user data directory (since r7058)</li>
100 * <li>{@code josmplugindir://SOME/FILE} file inside josm plugin directory (since r7834)</li></ul>
101 * @return this object
102 */
103 public CachedFile setName(String name) {
104 this.name = name;
105 return this;
106 }
107
108 /**
109 * Set maximum age of cache file. Only applies to URLs.
110 * When this time has passed after the last download of the file, the
111 * cache is considered stale and a new download will be attempted.
112 * @param maxAge the maximum cache age in seconds
113 * @return this object
114 */
115 public CachedFile setMaxAge(long maxAge) {
116 this.maxAge = maxAge;
117 return this;
118 }
119
120 /**
121 * Set the destination directory for the cache file. Only applies to URLs.
122 * @param destDir the destination directory
123 * @return this object
124 */
125 public CachedFile setDestDir(String destDir) {
126 this.destDir = destDir;
127 return this;
128 }
129
130 /**
131 * Set the accepted MIME types sent in the HTTP Accept header. Only applies to URLs.
132 * @param httpAccept the accepted MIME types
133 * @return this object
134 */
135 public CachedFile setHttpAccept(String httpAccept) {
136 this.httpAccept = httpAccept;
137 return this;
138 }
139
140 /**
141 * Set the caching strategy. Only applies to URLs.
142 * @param cachingStrategy caching strategy
143 * @return this object
144 */
145 public CachedFile setCachingStrategy(CachingStrategy cachingStrategy) {
146 this.cachingStrategy = cachingStrategy;
147 return this;
148 }
149
150 /**
151 * Sets the http headers. Only applies to URL pointing to http or https resources
152 * @param headers that should be sent together with request
153 * @return this object
154 */
155 public CachedFile setHttpHeaders(Map<String, String> headers) {
156 this.httpHeaders.putAll(headers);
157 return this;
158 }
159
160 public String getName() {
161 return name;
162 }
163
164 public long getMaxAge() {
165 return maxAge;
166 }
167
168 public String getDestDir() {
169 return destDir;
170 }
171
172 public String getHttpAccept() {
173 return httpAccept;
174 }
175
176 public CachingStrategy getCachingStrategy() {
177 return cachingStrategy;
178 }
179
180 /**
181 * Get InputStream to the requested resource.
182 * @return the InputStream
183 * @throws IOException when the resource with the given name could not be retrieved
184 */
185 public InputStream getInputStream() throws IOException {
186 File file = getFile();
187 if (file == null) {
188 if (name.startsWith("resource://")) {
189 InputStream is = getClass().getResourceAsStream(
190 name.substring("resource:/".length()));
191 if (is == null)
192 throw new IOException(tr("Failed to open input stream for resource ''{0}''", name));
193 return is;
194 } else {
195 throw new IOException("No file found for: "+name);
196 }
197 }
198 return new FileInputStream(file);
199 }
200
201 /**
202 * Get local file for the requested resource.
203 * @return The local cache file for URLs. If the resource is a local file,
204 * returns just that file.
205 * @throws IOException when the resource with the given name could not be retrieved
206 */
207 public synchronized File getFile() throws IOException {
208 if (initialized)
209 return cacheFile;
210 initialized = true;
211 URL url;
212 try {
213 url = new URL(name);
214 if ("file".equals(url.getProtocol())) {
215 cacheFile = new File(name.substring("file:/".length() - 1));
216 if (!cacheFile.exists()) {
217 cacheFile = new File(name.substring("file://".length() - 1));
218 }
219 } else {
220 cacheFile = checkLocal(url);
221 }
222 } catch (MalformedURLException e) {
223 if (name.startsWith("resource://")) {
224 return null;
225 } else if (name.startsWith("josmdir://")) {
226 cacheFile = new File(Main.pref.getUserDataDirectory(), name.substring("josmdir://".length()));
227 } else if (name.startsWith("josmplugindir://")) {
228 cacheFile = new File(Main.pref.getPluginsDirectory(), name.substring("josmplugindir://".length()));
229 } else {
230 cacheFile = new File(name);
231 }
232 }
233 if (cacheFile == null)
234 throw new IOException("Unable to get cache file for "+name);
235 return cacheFile;
236 }
237
238 /**
239 * Looks for a certain entry inside a zip file and returns the entry path.
240 *
241 * Replies a file in the top level directory of the ZIP file which has an
242 * extension <code>extension</code>. If more than one files have this
243 * extension, the last file whose name includes <code>namepart</code>
244 * is opened.
245 *
246 * @param extension the extension of the file we're looking for
247 * @param namepart the name part
248 * @return The zip entry path of the matching file. Null if this cached file
249 * doesn't represent a zip file or if there was no matching
250 * file in the ZIP file.
251 */
252 public String findZipEntryPath(String extension, String namepart) {
253 Pair<String, InputStream> ze = findZipEntryImpl(extension, namepart);
254 if (ze == null) return null;
255 return ze.a;
256 }
257
258 /**
259 * Like {@link #findZipEntryPath}, but returns the corresponding InputStream.
260 * @param extension the extension of the file we're looking for
261 * @param namepart the name part
262 * @return InputStream to the matching file. Null if this cached file
263 * doesn't represent a zip file or if there was no matching
264 * file in the ZIP file.
265 * @since 6148
266 */
267 public InputStream findZipEntryInputStream(String extension, String namepart) {
268 Pair<String, InputStream> ze = findZipEntryImpl(extension, namepart);
269 if (ze == null) return null;
270 return ze.b;
271 }
272
273 private Pair<String, InputStream> findZipEntryImpl(String extension, String namepart) {
274 File file = null;
275 try {
276 file = getFile();
277 } catch (IOException ex) {
278 Main.warn(ex, false);
279 }
280 if (file == null)
281 return null;
282 Pair<String, InputStream> res = null;
283 try {
284 ZipFile zipFile = new ZipFile(file, StandardCharsets.UTF_8);
285 ZipEntry resentry = null;
286 Enumeration<? extends ZipEntry> entries = zipFile.entries();
287 while (entries.hasMoreElements()) {
288 ZipEntry entry = entries.nextElement();
289 if (entry.getName().endsWith('.' + extension)) {
290 /* choose any file with correct extension. When more than
291 one file, prefer the one which matches namepart */
292 if (resentry == null || entry.getName().indexOf(namepart) >= 0) {
293 resentry = entry;
294 }
295 }
296 }
297 if (resentry != null) {
298 InputStream is = zipFile.getInputStream(resentry);
299 res = Pair.create(resentry.getName(), is);
300 } else {
301 Utils.close(zipFile);
302 }
303 } catch (Exception e) {
304 if (file.getName().endsWith(".zip")) {
305 Main.warn(tr("Failed to open file with extension ''{2}'' and namepart ''{3}'' in zip file ''{0}''. Exception was: {1}",
306 file.getName(), e.toString(), extension, namepart));
307 }
308 }
309 return res;
310 }
311
312 /**
313 * Clear the cache for the given resource.
314 * This forces a fresh download.
315 * @param name the URL
316 */
317 public static void cleanup(String name) {
318 cleanup(name, null);
319 }
320
321 /**
322 * Clear the cache for the given resource.
323 * This forces a fresh download.
324 * @param name the URL
325 * @param destDir the destination directory (see {@link #setDestDir(java.lang.String)})
326 */
327 public static void cleanup(String name, String destDir) {
328 URL url;
329 try {
330 url = new URL(name);
331 if (!"file".equals(url.getProtocol())) {
332 String prefKey = getPrefKey(url, destDir);
333 List<String> localPath = new ArrayList<>(Main.pref.getCollection(prefKey));
334 if (localPath.size() == 2) {
335 File lfile = new File(localPath.get(1));
336 if (lfile.exists()) {
337 Utils.deleteFile(lfile);
338 }
339 }
340 Main.pref.putCollection(prefKey, null);
341 }
342 } catch (MalformedURLException e) {
343 Main.warn(e);
344 }
345 }
346
347 /**
348 * Get preference key to store the location and age of the cached file.
349 * 2 resources that point to the same url, but that are to be stored in different
350 * directories will not share a cache file.
351 * @param url URL
352 * @param destDir destination directory
353 * @return Preference key
354 */
355 private static String getPrefKey(URL url, String destDir) {
356 StringBuilder prefKey = new StringBuilder("mirror.");
357 if (destDir != null) {
358 prefKey.append(destDir).append('.');
359 }
360 prefKey.append(url.toString());
361 return prefKey.toString().replaceAll("=", "_");
362 }
363
364 private File checkLocal(URL url) throws IOException {
365 String prefKey = getPrefKey(url, destDir);
366 String urlStr = url.toExternalForm();
367 long age = 0L;
368 long lMaxAge = maxAge;
369 Long ifModifiedSince = null;
370 File localFile = null;
371 List<String> localPathEntry = new ArrayList<>(Main.pref.getCollection(prefKey));
372 boolean offline = false;
373 try {
374 checkOfflineAccess(urlStr);
375 } catch (OfflineAccessException e) {
376 offline = true;
377 }
378 if (localPathEntry.size() == 2) {
379 localFile = new File(localPathEntry.get(1));
380 if (!localFile.exists()) {
381 localFile = null;
382 } else {
383 if (maxAge == DEFAULT_MAXTIME
384 || maxAge <= 0 // arbitrary value <= 0 is deprecated
385 ) {
386 lMaxAge = Main.pref.getInteger("mirror.maxtime", 7*24*60*60); // one week
387 }
388 age = System.currentTimeMillis() - Long.parseLong(localPathEntry.get(0));
389 if (offline || age < lMaxAge*1000) {
390 return localFile;
391 }
392 if (cachingStrategy == CachingStrategy.IfModifiedSince) {
393 ifModifiedSince = Long.valueOf(localPathEntry.get(0));
394 }
395 }
396 }
397 if (destDir == null) {
398 destDir = Main.pref.getCacheDirectory().getPath();
399 }
400
401 File destDirFile = new File(destDir);
402 if (!destDirFile.exists()) {
403 destDirFile.mkdirs();
404 }
405
406 // No local file + offline => nothing to do
407 if (offline) {
408 return null;
409 }
410
411 String a = urlStr.replaceAll("[^A-Za-z0-9_.-]", "_");
412 String localPath = "mirror_" + a;
413 destDirFile = new File(destDir, localPath + ".tmp");
414 try {
415 final HttpClient.Response con = HttpClient.create(url)
416 .setAccept(httpAccept)
417 .setIfModifiedSince(ifModifiedSince == null ? 0L : ifModifiedSince)
418 .setHeaders(httpHeaders)
419 .connect();
420 if (ifModifiedSince != null && con.getResponseCode() == HttpURLConnection.HTTP_NOT_MODIFIED) {
421 if (Main.isDebugEnabled()) {
422 Main.debug("304 Not Modified ("+urlStr+')');
423 }
424 if (localFile == null)
425 throw new AssertionError();
426 Main.pref.putCollection(prefKey,
427 Arrays.asList(Long.toString(System.currentTimeMillis()), localPathEntry.get(1)));
428 return localFile;
429 }
430 try (InputStream bis = new BufferedInputStream(con.getContent())) {
431 Files.copy(bis, destDirFile.toPath(), StandardCopyOption.REPLACE_EXISTING);
432 }
433 localFile = new File(destDir, localPath);
434 if (Main.platform.rename(destDirFile, localFile)) {
435 Main.pref.putCollection(prefKey,
436 Arrays.asList(Long.toString(System.currentTimeMillis()), localFile.toString()));
437 } else {
438 Main.warn(tr("Failed to rename file {0} to {1}.",
439 destDirFile.getPath(), localFile.getPath()));
440 }
441 } catch (IOException e) {
442 if (age >= lMaxAge*1000 && age < lMaxAge*1000*2) {
443 Main.warn(tr("Failed to load {0}, use cached file and retry next time: {1}", urlStr, e));
444 return localFile;
445 } else {
446 throw e;
447 }
448 }
449
450 return localFile;
451 }
452
453 private static void checkOfflineAccess(String urlString) {
454 OnlineResource.JOSM_WEBSITE.checkOfflineAccess(urlString, Main.getJOSMWebsite());
455 OnlineResource.OSM_API.checkOfflineAccess(urlString, Main.pref.get("osm-server.url", OsmApi.DEFAULT_API_URL));
456 }
457
458}
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