// License: GPL. For details, see LICENSE file.
package org.openstreetmap.josm.io;
import static org.openstreetmap.josm.tools.I18n.tr;
import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.ByteArrayOutputStream;
import java.io.Closeable;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.StandardCopyOption;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Enumeration;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;
import org.openstreetmap.josm.Main;
import org.openstreetmap.josm.tools.HttpClient;
import org.openstreetmap.josm.tools.Pair;
import org.openstreetmap.josm.tools.Utils;
/**
* Downloads a file and caches it on disk in order to reduce network load.
*
* Supports URLs, local files, and a custom scheme (resource:
) to get
* resources from the current *.jar file. (Local caching is only done for URLs.)
*
* The mirrored file is only downloaded if it has been more than 7 days since
* last download. (Time can be configured.)
*
* The file content is normally accessed with {@link #getInputStream()}, but
* you can also get the mirrored copy with {@link #getFile()}.
*/
public class CachedFile implements Closeable {
/**
* Caching strategy.
*/
public enum CachingStrategy {
/**
* If cached file on disk is older than a certain time (7 days by default),
* consider the cache stale and try to download the file again.
*/
MaxAge,
/**
* Similar to MaxAge, considers the cache stale when a certain age is
* exceeded. In addition, a If-Modified-Since HTTP header is added.
* When the server replies "304 Not Modified", this is considered the same
* as a full download.
*/
IfModifiedSince
}
protected String name;
protected long maxAge;
protected String destDir;
protected String httpAccept;
protected CachingStrategy cachingStrategy;
private boolean fastFail;
private HttpClient activeConnection;
protected File cacheFile;
protected boolean initialized;
public static final long DEFAULT_MAXTIME = -1L;
public static final long DAYS = 24L*60L*60L; // factor to get caching time in days
private final Map httpHeaders = new ConcurrentHashMap<>();
/**
* Constructs a CachedFile object from a given filename, URL or internal resource.
*
* @param name can be:
* - relative or absolute file name
* - {@code file:///SOME/FILE} the same as above
* - {@code http://...} a URL. It will be cached on disk.
* - {@code resource://SOME/FILE} file from the classpath (usually in the current *.jar)
* - {@code josmdir://SOME/FILE} file inside josm user data directory (since r7058)
* - {@code josmplugindir://SOME/FILE} file inside josm plugin directory (since r7834)
*/
public CachedFile(String name) {
this.name = name;
}
/**
* Set the name of the resource.
* @param name can be:
* - relative or absolute file name
* - {@code file:///SOME/FILE} the same as above
* - {@code http://...} a URL. It will be cached on disk.
* - {@code resource://SOME/FILE} file from the classpath (usually in the current *.jar)
* - {@code josmdir://SOME/FILE} file inside josm user data directory (since r7058)
* - {@code josmplugindir://SOME/FILE} file inside josm plugin directory (since r7834)
* @return this object
*/
public CachedFile setName(String name) {
this.name = name;
return this;
}
/**
* Set maximum age of cache file. Only applies to URLs.
* When this time has passed after the last download of the file, the
* cache is considered stale and a new download will be attempted.
* @param maxAge the maximum cache age in seconds
* @return this object
*/
public CachedFile setMaxAge(long maxAge) {
this.maxAge = maxAge;
return this;
}
/**
* Set the destination directory for the cache file. Only applies to URLs.
* @param destDir the destination directory
* @return this object
*/
public CachedFile setDestDir(String destDir) {
this.destDir = destDir;
return this;
}
/**
* Set the accepted MIME types sent in the HTTP Accept header. Only applies to URLs.
* @param httpAccept the accepted MIME types
* @return this object
*/
public CachedFile setHttpAccept(String httpAccept) {
this.httpAccept = httpAccept;
return this;
}
/**
* Set the caching strategy. Only applies to URLs.
* @param cachingStrategy caching strategy
* @return this object
*/
public CachedFile setCachingStrategy(CachingStrategy cachingStrategy) {
this.cachingStrategy = cachingStrategy;
return this;
}
/**
* Sets the http headers. Only applies to URL pointing to http or https resources
* @param headers that should be sent together with request
* @return this object
*/
public CachedFile setHttpHeaders(Map headers) {
this.httpHeaders.putAll(headers);
return this;
}
/**
* Sets whether opening HTTP connections should fail fast, i.e., whether a
* {@link HttpClient#setConnectTimeout(int) low connect timeout} should be used.
* @param fastFail whether opening HTTP connections should fail fast
*/
public void setFastFail(boolean fastFail) {
this.fastFail = fastFail;
}
public String getName() {
return name;
}
/**
* Returns maximum age of cache file. Only applies to URLs.
* When this time has passed after the last download of the file, the
* cache is considered stale and a new download will be attempted.
* @return the maximum cache age in seconds
*/
public long getMaxAge() {
return maxAge;
}
public String getDestDir() {
return destDir;
}
public String getHttpAccept() {
return httpAccept;
}
public CachingStrategy getCachingStrategy() {
return cachingStrategy;
}
/**
* Get InputStream to the requested resource.
* @return the InputStream
* @throws IOException when the resource with the given name could not be retrieved
*/
public InputStream getInputStream() throws IOException {
File file = getFile();
if (file == null) {
if (name.startsWith("resource://")) {
InputStream is = getClass().getResourceAsStream(
name.substring("resource:/".length()));
if (is == null)
throw new IOException(tr("Failed to open input stream for resource ''{0}''", name));
return is;
} else {
throw new IOException("No file found for: "+name);
}
}
return new FileInputStream(file);
}
/**
* Get the full content of the requested resource as a byte array.
* @return the full content of the requested resource as byte array
* @throws IOException in case of an I/O error
*/
public byte[] getByteContent() throws IOException {
try (InputStream is = getInputStream()) {
ByteArrayOutputStream buffer = new ByteArrayOutputStream();
int nRead;
byte[] data = new byte[8192];
while ((nRead = is.read(data, 0, data.length)) != -1) {
buffer.write(data, 0, nRead);
}
buffer.flush();
return buffer.toByteArray();
}
}
/**
* Returns {@link #getInputStream()} wrapped in a buffered reader.
*
* Detects Unicode charset in use utilizing {@link UTFInputStreamReader}.
*
* @return buffered reader
* @throws IOException if any I/O error occurs
* @since 9411
*/
public BufferedReader getContentReader() throws IOException {
return new BufferedReader(UTFInputStreamReader.create(getInputStream()));
}
/**
* Get local file for the requested resource.
* @return The local cache file for URLs. If the resource is a local file,
* returns just that file.
* @throws IOException when the resource with the given name could not be retrieved
*/
public synchronized File getFile() throws IOException {
if (initialized)
return cacheFile;
initialized = true;
URL url;
try {
url = new URL(name);
if ("file".equals(url.getProtocol())) {
cacheFile = new File(name.substring("file:/".length() - 1));
if (!cacheFile.exists()) {
cacheFile = new File(name.substring("file://".length() - 1));
}
} else {
cacheFile = checkLocal(url);
}
} catch (MalformedURLException e) {
if (name.startsWith("resource://")) {
return null;
} else if (name.startsWith("josmdir://")) {
cacheFile = new File(Main.pref.getUserDataDirectory(), name.substring("josmdir://".length()));
} else if (name.startsWith("josmplugindir://")) {
cacheFile = new File(Main.pref.getPluginsDirectory(), name.substring("josmplugindir://".length()));
} else {
cacheFile = new File(name);
}
}
if (cacheFile == null)
throw new IOException("Unable to get cache file for "+name);
return cacheFile;
}
/**
* Looks for a certain entry inside a zip file and returns the entry path.
*
* Replies a file in the top level directory of the ZIP file which has an
* extension extension
. If more than one files have this
* extension, the last file whose name includes namepart
* is opened.
*
* @param extension the extension of the file we're looking for
* @param namepart the name part
* @return The zip entry path of the matching file. Null if this cached file
* doesn't represent a zip file or if there was no matching
* file in the ZIP file.
*/
public String findZipEntryPath(String extension, String namepart) {
Pair ze = findZipEntryImpl(extension, namepart);
if (ze == null) return null;
return ze.a;
}
/**
* Like {@link #findZipEntryPath}, but returns the corresponding InputStream.
* @param extension the extension of the file we're looking for
* @param namepart the name part
* @return InputStream to the matching file. Null if this cached file
* doesn't represent a zip file or if there was no matching
* file in the ZIP file.
* @since 6148
*/
public InputStream findZipEntryInputStream(String extension, String namepart) {
Pair ze = findZipEntryImpl(extension, namepart);
if (ze == null) return null;
return ze.b;
}
private Pair findZipEntryImpl(String extension, String namepart) {
File file = null;
try {
file = getFile();
} catch (IOException ex) {
Main.warn(ex, false);
}
if (file == null)
return null;
Pair res = null;
try {
ZipFile zipFile = new ZipFile(file, StandardCharsets.UTF_8);
ZipEntry resentry = null;
Enumeration extends ZipEntry> entries = zipFile.entries();
while (entries.hasMoreElements()) {
ZipEntry entry = entries.nextElement();
if (entry.getName().endsWith('.' + extension)) {
/* choose any file with correct extension. When more than
one file, prefer the one which matches namepart */
if (resentry == null || entry.getName().indexOf(namepart) >= 0) {
resentry = entry;
}
}
}
if (resentry != null) {
InputStream is = zipFile.getInputStream(resentry);
res = Pair.create(resentry.getName(), is);
} else {
Utils.close(zipFile);
}
} catch (IOException e) {
if (file.getName().endsWith(".zip")) {
Main.warn(e, tr("Failed to open file with extension ''{2}'' and namepart ''{3}'' in zip file ''{0}''. Exception was: {1}",
file.getName(), e.toString(), extension, namepart));
}
}
return res;
}
/**
* Clear the cache for the given resource.
* This forces a fresh download.
* @param name the URL
*/
public static void cleanup(String name) {
cleanup(name, null);
}
/**
* Clear the cache for the given resource.
* This forces a fresh download.
* @param name the URL
* @param destDir the destination directory (see {@link #setDestDir(java.lang.String)})
*/
public static void cleanup(String name, String destDir) {
URL url;
try {
url = new URL(name);
if (!"file".equals(url.getProtocol())) {
String prefKey = getPrefKey(url, destDir);
List localPath = new ArrayList<>(Main.pref.getCollection(prefKey));
if (localPath.size() == 2) {
File lfile = new File(localPath.get(1));
if (lfile.exists()) {
Utils.deleteFile(lfile);
}
}
Main.pref.putCollection(prefKey, null);
}
} catch (MalformedURLException e) {
Main.warn(e);
}
}
/**
* Get preference key to store the location and age of the cached file.
* 2 resources that point to the same url, but that are to be stored in different
* directories will not share a cache file.
* @param url URL
* @param destDir destination directory
* @return Preference key
*/
private static String getPrefKey(URL url, String destDir) {
StringBuilder prefKey = new StringBuilder("mirror.");
if (destDir != null) {
prefKey.append(destDir).append('.');
}
prefKey.append(url.toString());
return prefKey.toString().replaceAll("=", "_");
}
private File checkLocal(URL url) throws IOException {
String prefKey = getPrefKey(url, destDir);
String urlStr = url.toExternalForm();
long age = 0L;
long lMaxAge = maxAge;
Long ifModifiedSince = null;
File localFile = null;
List localPathEntry = new ArrayList<>(Main.pref.getCollection(prefKey));
boolean offline = false;
try {
checkOfflineAccess(urlStr);
} catch (OfflineAccessException e) {
Main.trace(e);
offline = true;
}
if (localPathEntry.size() == 2) {
localFile = new File(localPathEntry.get(1));
if (!localFile.exists()) {
localFile = null;
} else {
if (maxAge == DEFAULT_MAXTIME
|| maxAge <= 0 // arbitrary value <= 0 is deprecated
) {
lMaxAge = Main.pref.getInteger("mirror.maxtime", 7*24*60*60); // one week
}
age = System.currentTimeMillis() - Long.parseLong(localPathEntry.get(0));
if (offline || age < lMaxAge*1000) {
return localFile;
}
if (cachingStrategy == CachingStrategy.IfModifiedSince) {
ifModifiedSince = Long.valueOf(localPathEntry.get(0));
}
}
}
if (destDir == null) {
destDir = Main.pref.getCacheDirectory().getPath();
}
File destDirFile = new File(destDir);
if (!destDirFile.exists()) {
Utils.mkDirs(destDirFile);
}
// No local file + offline => nothing to do
if (offline) {
return null;
}
String a = urlStr.replaceAll("[^A-Za-z0-9_.-]", "_");
String localPath = "mirror_" + a;
destDirFile = new File(destDir, localPath + ".tmp");
try {
activeConnection = HttpClient.create(url)
.setAccept(httpAccept)
.setIfModifiedSince(ifModifiedSince == null ? 0L : ifModifiedSince)
.setHeaders(httpHeaders);
if (fastFail) {
activeConnection.setReadTimeout(1000);
}
final HttpClient.Response con = activeConnection.connect();
if (ifModifiedSince != null && con.getResponseCode() == HttpURLConnection.HTTP_NOT_MODIFIED) {
if (Main.isDebugEnabled()) {
Main.debug("304 Not Modified ("+urlStr+')');
}
if (localFile == null)
throw new AssertionError();
Main.pref.putCollection(prefKey,
Arrays.asList(Long.toString(System.currentTimeMillis()), localPathEntry.get(1)));
return localFile;
}
try (InputStream bis = new BufferedInputStream(con.getContent())) {
Files.copy(bis, destDirFile.toPath(), StandardCopyOption.REPLACE_EXISTING);
}
activeConnection = null;
localFile = new File(destDir, localPath);
if (Main.platform.rename(destDirFile, localFile)) {
Main.pref.putCollection(prefKey,
Arrays.asList(Long.toString(System.currentTimeMillis()), localFile.toString()));
} else {
Main.warn(tr("Failed to rename file {0} to {1}.",
destDirFile.getPath(), localFile.getPath()));
}
} catch (IOException e) {
if (age >= lMaxAge*1000 && age < lMaxAge*1000*2) {
Main.warn(tr("Failed to load {0}, use cached file and retry next time: {1}", urlStr, e));
return localFile;
} else {
throw e;
}
}
return localFile;
}
private static void checkOfflineAccess(String urlString) {
OnlineResource.JOSM_WEBSITE.checkOfflineAccess(urlString, Main.getJOSMWebsite());
OnlineResource.OSM_API.checkOfflineAccess(urlString, OsmApi.getOsmApi().getServerUrl());
}
/**
* Attempts to disconnect an URL connection.
* @see HttpClient#disconnect()
* @since 9411
*/
@Override
public void close() {
if (activeConnection != null) {
activeConnection.disconnect();
}
}
}