// 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.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Enumeration;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
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.CheckParameterUtil;
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 {
/**
* 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;
protected File cacheFile = null;
protected boolean initialized = false;
public static final long DEFAULT_MAXTIME = -1L;
public static final long DAYS = 24*60*60; // factor to get caching time in days
private 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;
}
public String getName() {
return name;
}
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 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 (Exception e) {
if (file.getName().endsWith(".zip")) {
Main.warn(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()) {
lfile.delete();
}
}
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.
*/
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) {
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()) {
destDirFile.mkdirs();
}
// 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 {
HttpURLConnection con = connectFollowingRedirect(url, httpAccept, ifModifiedSince, httpHeaders);
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.getInputStream());
OutputStream fos = new FileOutputStream(destDirFile);
OutputStream bos = new BufferedOutputStream(fos)
) {
byte[] buffer = new byte[4096];
int length;
while ((length = bis.read(buffer)) > -1) {
bos.write(buffer, 0, length);
}
}
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, Main.pref.get("osm-server.url", OsmApi.DEFAULT_API_URL));
}
/**
* Opens a connection for downloading a resource.
*
* Manually follows redirects because
* {@link HttpURLConnection#setFollowRedirects(boolean)} fails if the redirect
* is going from a http to a https URL, see bug report.
*
* This can cause problems when downloading from certain GitHub URLs.
*
* @param downloadUrl The resource URL to download
* @param httpAccept The accepted MIME types sent in the HTTP Accept header. Can be {@code null}
* @param ifModifiedSince The download time of the cache file, optional
* @return The HTTP connection effectively linked to the resource, after all potential redirections
* @throws MalformedURLException If a redirected URL is wrong
* @throws IOException If any I/O operation goes wrong
* @throws OfflineAccessException if resource is accessed in offline mode, in any protocol
* @since 6867
*/
public static HttpURLConnection connectFollowingRedirect(URL downloadUrl, String httpAccept, Long ifModifiedSince)
throws MalformedURLException, IOException {
return connectFollowingRedirect(downloadUrl, httpAccept, ifModifiedSince, null);
}
/**
* Opens a connection for downloading a resource.
*
* Manually follows redirects because
* {@link HttpURLConnection#setFollowRedirects(boolean)} fails if the redirect
* is going from a http to a https URL, see bug report.
*
* This can cause problems when downloading from certain GitHub URLs.
*
* @param downloadUrl The resource URL to download
* @param httpAccept The accepted MIME types sent in the HTTP Accept header. Can be {@code null}
* @param ifModifiedSince The download time of the cache file, optional
* @param headers http headers to be sent together with http request
* @return The HTTP connection effectively linked to the resource, after all potential redirections
* @throws MalformedURLException If a redirected URL is wrong
* @throws IOException If any I/O operation goes wrong
* @throws OfflineAccessException if resource is accessed in offline mode, in any protocol
* @since TODO
*/
public static HttpURLConnection connectFollowingRedirect(URL downloadUrl, String httpAccept, Long ifModifiedSince,
Map headers) throws MalformedURLException, IOException {
CheckParameterUtil.ensureParameterNotNull(downloadUrl, "downloadUrl");
String downloadString = downloadUrl.toExternalForm();
checkOfflineAccess(downloadString);
int numRedirects = 0;
while (true) {
HttpURLConnection con = Utils.openHttpConnection(downloadUrl);
if (ifModifiedSince != null) {
con.setIfModifiedSince(ifModifiedSince);
}
if (headers != null) {
for (Entry header: headers.entrySet()) {
con.setRequestProperty(header.getKey(), header.getValue());
}
}
con.setInstanceFollowRedirects(false);
con.setConnectTimeout(Main.pref.getInteger("socket.timeout.connect", 15)*1000);
con.setReadTimeout(Main.pref.getInteger("socket.timeout.read", 30)*1000);
if (Main.isDebugEnabled()) {
Main.debug("GET "+downloadString);
}
if (httpAccept != null) {
if (Main.isTraceEnabled()) {
Main.trace("Accept: "+httpAccept);
}
con.setRequestProperty("Accept", httpAccept);
}
try {
con.connect();
} catch (IOException e) {
Main.addNetworkError(downloadUrl, Utils.getRootCause(e));
throw e;
}
switch(con.getResponseCode()) {
case HttpURLConnection.HTTP_OK:
return con;
case HttpURLConnection.HTTP_NOT_MODIFIED:
if (ifModifiedSince != null)
return con;
case HttpURLConnection.HTTP_MOVED_PERM:
case HttpURLConnection.HTTP_MOVED_TEMP:
case HttpURLConnection.HTTP_SEE_OTHER:
String redirectLocation = con.getHeaderField("Location");
if (redirectLocation == null) {
/* I18n: argument is HTTP response code */
String msg = tr("Unexpected response from HTTP server. Got {0} response without ''Location'' header."+
" Can''t redirect. Aborting.", con.getResponseCode());
throw new IOException(msg);
}
downloadUrl = new URL(redirectLocation);
downloadString = downloadUrl.toExternalForm();
// keep track of redirect attempts to break a redirect loops if it happens
// to occur for whatever reason
numRedirects++;
if (numRedirects >= Main.pref.getInteger("socket.maxredirects", 5)) {
String msg = tr("Too many redirects to the download URL detected. Aborting.");
throw new IOException(msg);
}
Main.info(tr("Download redirected to ''{0}''", downloadString));
break;
default:
String msg = tr("Failed to read from ''{0}''. Server responded with status code {1}.", downloadString, con.getResponseCode());
throw new IOException(msg);
}
}
}
}