Java tutorial
/* * Copyright (C) 2012 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.google.android.vending.expansion.downloader.impl; import com.google.android.vending.expansion.downloader.Constants; import com.google.android.vending.expansion.downloader.Helpers; import com.google.android.vending.expansion.downloader.IDownloaderClient; import org.apache.http.Header; import org.apache.http.HttpHost; import org.apache.http.HttpResponse; import org.apache.http.client.methods.HttpGet; import org.apache.http.conn.params.ConnRouteParams; import android.content.Context; import android.net.Proxy; import android.os.PowerManager; import android.os.Process; import android.util.Log; import java.io.File; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.SyncFailedException; import java.net.URI; import java.net.URISyntaxException; import java.util.Locale; /** * Runs an actual download */ public class DownloadThread { private Context mContext; private DownloadInfo mInfo; private DownloaderService mService; private final DownloadsDB mDB; private final DownloadNotification mNotification; private String mUserAgent; public DownloadThread(DownloadInfo info, DownloaderService service, DownloadNotification notification) { mContext = service; mInfo = info; mService = service; mNotification = notification; mDB = DownloadsDB.getDB(service); mUserAgent = "APKXDL (Linux; U; Android " + android.os.Build.VERSION.RELEASE + ";" + Locale.getDefault().toString() + "; " + android.os.Build.DEVICE + "/" + android.os.Build.ID + ")" + service.getPackageName(); } /** * Returns the default user agent */ private String userAgent() { return mUserAgent; } /** * State for the entire run() method. */ private static class State { public String mFilename; public FileOutputStream mStream; public boolean mCountRetry = false; public int mRetryAfter = 0; public int mRedirectCount = 0; public String mNewUri; public boolean mGotData = false; public String mRequestUri; public State(DownloadInfo info, DownloaderService service) { mRedirectCount = info.mRedirectCount; mRequestUri = info.mUri; mFilename = service.generateTempSaveFileName(info.mFileName); } } /** * State within executeDownload() */ private static class InnerState { public int mBytesSoFar = 0; public int mBytesThisSession = 0; public String mHeaderETag; public boolean mContinuingDownload = false; public String mHeaderContentLength; public String mHeaderContentDisposition; public String mHeaderContentLocation; public int mBytesNotified = 0; public long mTimeLastNotification = 0; } /** * Raised from methods called by run() to indicate that the current request * should be stopped immediately. Note the message passed to this exception * will be logged and therefore must be guaranteed not to contain any PII, * meaning it generally can't include any information about the request URI, * headers, or destination filename. */ private class StopRequest extends Throwable { /** * */ private static final long serialVersionUID = 6338592678988347973L; public int mFinalStatus; public StopRequest(int finalStatus, String message) { super(message); mFinalStatus = finalStatus; } public StopRequest(int finalStatus, String message, Throwable throwable) { super(message, throwable); mFinalStatus = finalStatus; } } /** * Raised from methods called by executeDownload() to indicate that the * download should be retried immediately. */ private class RetryDownload extends Throwable { /** * */ private static final long serialVersionUID = 6196036036517540229L; } /** * Returns the preferred proxy to be used by clients. This is a wrapper * around {@link android.net.Proxy#getHost()}. Currently no proxy will be * returned for localhost or if the active network is Wi-Fi. * * @param context the context which will be passed to * {@link android.net.Proxy#getHost()} * @param url the target URL for the request * @note Calling this method requires permission * android.permission.ACCESS_NETWORK_STATE * @return The preferred proxy to be used by clients, or null if there is no * proxy. */ public HttpHost getPreferredHttpHost(Context context, String url) { if (!isLocalHost(url) && !mService.isWiFi()) { final String proxyHost = Proxy.getHost(context); if (proxyHost != null) { return new HttpHost(proxyHost, Proxy.getPort(context), "http"); } } return null; } static final private boolean isLocalHost(String url) { if (url == null) { return false; } try { final URI uri = URI.create(url); final String host = uri.getHost(); if (host != null) { // TODO: InetAddress.isLoopbackAddress should be used to check // for localhost. However no public factory methods exist which // can be used without triggering DNS lookup if host is not // localhost. if (host.equalsIgnoreCase("localhost") || host.equals("127.0.0.1") || host.equals("[::1]")) { return true; } } } catch (IllegalArgumentException iex) { // Ignore (URI.create) } return false; } /** * Executes the download in a separate thread */ public void run() { Process.setThreadPriority(Process.THREAD_PRIORITY_BACKGROUND); State state = new State(mInfo, mService); AndroidHttpClient client = null; PowerManager.WakeLock wakeLock = null; int finalStatus = DownloaderService.STATUS_UNKNOWN_ERROR; try { PowerManager pm = (PowerManager) mContext.getSystemService(Context.POWER_SERVICE); wakeLock = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, Constants.TAG); wakeLock.acquire(); if (Constants.LOGV) { Log.v(Constants.TAG, "initiating download for " + mInfo.mFileName); Log.v(Constants.TAG, " at " + mInfo.mUri); } client = AndroidHttpClient.newInstance(userAgent(), mContext); boolean finished = false; while (!finished) { if (Constants.LOGV) { Log.v(Constants.TAG, "initiating download for " + mInfo.mFileName); Log.v(Constants.TAG, " at " + mInfo.mUri); } // Set or unset proxy, which may have changed since last GET // request. // setDefaultProxy() supports null as proxy parameter. ConnRouteParams.setDefaultProxy(client.getParams(), getPreferredHttpHost(mContext, state.mRequestUri)); HttpGet request = new HttpGet(state.mRequestUri); try { executeDownload(state, client, request); finished = true; } catch (RetryDownload exc) { // fall through } finally { request.abort(); request = null; } } if (Constants.LOGV) { Log.v(Constants.TAG, "download completed for " + mInfo.mFileName); Log.v(Constants.TAG, " at " + mInfo.mUri); } finalizeDestinationFile(state); finalStatus = DownloaderService.STATUS_SUCCESS; } catch (StopRequest error) { // remove the cause before printing, in case it contains PII Log.w(Constants.TAG, "Aborting request for download " + mInfo.mFileName + ": " + error.getMessage()); error.printStackTrace(); finalStatus = error.mFinalStatus; // fall through to finally block } catch (Throwable ex) { // sometimes the socket code throws unchecked // exceptions Log.w(Constants.TAG, "Exception for " + mInfo.mFileName + ": " + ex); finalStatus = DownloaderService.STATUS_UNKNOWN_ERROR; // falls through to the code that reports an error } finally { if (wakeLock != null) { wakeLock.release(); wakeLock = null; } if (client != null) { client.close(); client = null; } cleanupDestination(state, finalStatus); notifyDownloadCompleted(finalStatus, state.mCountRetry, state.mRetryAfter, state.mRedirectCount, state.mGotData, state.mFilename); } } /** * Fully execute a single download request - setup and send the request, * handle the response, and transfer the data to the destination file. */ private void executeDownload(State state, AndroidHttpClient client, HttpGet request) throws StopRequest, RetryDownload { InnerState innerState = new InnerState(); byte data[] = new byte[Constants.BUFFER_SIZE]; checkPausedOrCanceled(state); setupDestinationFile(state, innerState); addRequestHeaders(innerState, request); // check just before sending the request to avoid using an invalid // connection at all checkConnectivity(state); mNotification.onDownloadStateChanged(IDownloaderClient.STATE_CONNECTING); HttpResponse response = sendRequest(state, client, request); handleExceptionalStatus(state, innerState, response); if (Constants.LOGV) { Log.v(Constants.TAG, "received response for " + mInfo.mUri); } processResponseHeaders(state, innerState, response); InputStream entityStream = openResponseEntity(state, response); mNotification.onDownloadStateChanged(IDownloaderClient.STATE_DOWNLOADING); transferData(state, innerState, data, entityStream); } /** * Check if current connectivity is valid for this request. */ private void checkConnectivity(State state) throws StopRequest { switch (mService.getNetworkAvailabilityState(mDB)) { case DownloaderService.NETWORK_OK: return; case DownloaderService.NETWORK_NO_CONNECTION: throw new StopRequest(DownloaderService.STATUS_WAITING_FOR_NETWORK, "waiting for network to return"); case DownloaderService.NETWORK_TYPE_DISALLOWED_BY_REQUESTOR: throw new StopRequest(DownloaderService.STATUS_QUEUED_FOR_WIFI_OR_CELLULAR_PERMISSION, "waiting for wifi or for download over cellular to be authorized"); case DownloaderService.NETWORK_CANNOT_USE_ROAMING: throw new StopRequest(DownloaderService.STATUS_WAITING_FOR_NETWORK, "roaming is not allowed"); case DownloaderService.NETWORK_UNUSABLE_DUE_TO_SIZE: throw new StopRequest(DownloaderService.STATUS_QUEUED_FOR_WIFI, "waiting for wifi"); } } /** * Transfer as much data as possible from the HTTP response to the * destination file. * * @param data buffer to use to read data * @param entityStream stream for reading the HTTP response entity */ private void transferData(State state, InnerState innerState, byte[] data, InputStream entityStream) throws StopRequest { for (;;) { int bytesRead = readFromResponse(state, innerState, data, entityStream); if (bytesRead == -1) { // success, end of stream already reached handleEndOfStream(state, innerState); return; } state.mGotData = true; writeDataToDestination(state, data, bytesRead); innerState.mBytesSoFar += bytesRead; innerState.mBytesThisSession += bytesRead; reportProgress(state, innerState); checkPausedOrCanceled(state); } } /** * Called after a successful completion to take any necessary action on the * downloaded file. */ private void finalizeDestinationFile(State state) throws StopRequest { syncDestination(state); String tempFilename = state.mFilename; String finalFilename = Helpers.generateSaveFileName(mService, mInfo.mFileName); if (!state.mFilename.equals(finalFilename)) { File startFile = new File(tempFilename); File destFile = new File(finalFilename); if (mInfo.mTotalBytes != -1 && mInfo.mCurrentBytes == mInfo.mTotalBytes) { if (!startFile.renameTo(destFile)) { throw new StopRequest(DownloaderService.STATUS_FILE_ERROR, "unable to finalize destination file"); } } else { throw new StopRequest(DownloaderService.STATUS_FILE_DELIVERED_INCORRECTLY, "file delivered with incorrect size. probably due to network not browser configured"); } } } /** * Called just before the thread finishes, regardless of status, to take any * necessary action on the downloaded file. */ private void cleanupDestination(State state, int finalStatus) { closeDestination(state); if (state.mFilename != null && DownloaderService.isStatusError(finalStatus)) { new File(state.mFilename).delete(); state.mFilename = null; } } /** * Sync the destination file to storage. */ private void syncDestination(State state) { FileOutputStream downloadedFileStream = null; try { downloadedFileStream = new FileOutputStream(state.mFilename, true); downloadedFileStream.getFD().sync(); } catch (FileNotFoundException ex) { Log.w(Constants.TAG, "file " + state.mFilename + " not found: " + ex); } catch (SyncFailedException ex) { Log.w(Constants.TAG, "file " + state.mFilename + " sync failed: " + ex); } catch (IOException ex) { Log.w(Constants.TAG, "IOException trying to sync " + state.mFilename + ": " + ex); } catch (RuntimeException ex) { Log.w(Constants.TAG, "exception while syncing file: ", ex); } finally { if (downloadedFileStream != null) { try { downloadedFileStream.close(); } catch (IOException ex) { Log.w(Constants.TAG, "IOException while closing synced file: ", ex); } catch (RuntimeException ex) { Log.w(Constants.TAG, "exception while closing file: ", ex); } } } } /** * Close the destination output stream. */ private void closeDestination(State state) { try { // close the file if (state.mStream != null) { state.mStream.close(); state.mStream = null; } } catch (IOException ex) { if (Constants.LOGV) { Log.v(Constants.TAG, "exception when closing the file after download : " + ex); } // nothing can really be done if the file can't be closed } } /** * Check if the download has been paused or canceled, stopping the request * appropriately if it has been. */ private void checkPausedOrCanceled(State state) throws StopRequest { if (mService.getControl() == DownloaderService.CONTROL_PAUSED) { int status = mService.getStatus(); switch (status) { case DownloaderService.STATUS_PAUSED_BY_APP: throw new StopRequest(mService.getStatus(), "download paused"); } } } /** * Report download progress through the database if necessary. */ private void reportProgress(State state, InnerState innerState) { long now = System.currentTimeMillis(); if (innerState.mBytesSoFar - innerState.mBytesNotified > Constants.MIN_PROGRESS_STEP && now - innerState.mTimeLastNotification > Constants.MIN_PROGRESS_TIME) { // we store progress updates to the database here mInfo.mCurrentBytes = innerState.mBytesSoFar; mDB.updateDownloadCurrentBytes(mInfo); innerState.mBytesNotified = innerState.mBytesSoFar; innerState.mTimeLastNotification = now; long totalBytesSoFar = innerState.mBytesThisSession + mService.mBytesSoFar; if (Constants.LOGVV) { Log.v(Constants.TAG, "downloaded " + mInfo.mCurrentBytes + " out of " + mInfo.mTotalBytes); Log.v(Constants.TAG, " total " + totalBytesSoFar + " out of " + mService.mTotalLength); } mService.notifyUpdateBytes(totalBytesSoFar); } } /** * Write a data buffer to the destination file. * * @param data buffer containing the data to write * @param bytesRead how many bytes to write from the buffer */ private void writeDataToDestination(State state, byte[] data, int bytesRead) throws StopRequest { for (;;) { try { if (state.mStream == null) { state.mStream = new FileOutputStream(state.mFilename, true); } state.mStream.write(data, 0, bytesRead); // we close after every write --- this may be too inefficient closeDestination(state); return; } catch (IOException ex) { if (!Helpers.isExternalMediaMounted()) { throw new StopRequest(DownloaderService.STATUS_DEVICE_NOT_FOUND_ERROR, "external media not mounted while writing destination file"); } long availableBytes = Helpers.getAvailableBytes(Helpers.getFilesystemRoot(state.mFilename)); if (availableBytes < bytesRead) { throw new StopRequest(DownloaderService.STATUS_INSUFFICIENT_SPACE_ERROR, "insufficient space while writing destination file", ex); } throw new StopRequest(DownloaderService.STATUS_FILE_ERROR, "while writing destination file: " + ex.toString(), ex); } } } /** * Called when we've reached the end of the HTTP response stream, to update * the database and check for consistency. */ private void handleEndOfStream(State state, InnerState innerState) throws StopRequest { mInfo.mCurrentBytes = innerState.mBytesSoFar; // this should always be set from the market // if ( innerState.mHeaderContentLength == null ) { // mInfo.mTotalBytes = innerState.mBytesSoFar; // } mDB.updateDownload(mInfo); boolean lengthMismatched = (innerState.mHeaderContentLength != null) && (innerState.mBytesSoFar != Integer.parseInt(innerState.mHeaderContentLength)); if (lengthMismatched) { if (cannotResume(innerState)) { throw new StopRequest(DownloaderService.STATUS_CANNOT_RESUME, "mismatched content length"); } else { throw new StopRequest(getFinalStatusForHttpError(state), "closed socket before end of file"); } } } private boolean cannotResume(InnerState innerState) { return innerState.mBytesSoFar > 0 && innerState.mHeaderETag == null; } /** * Read some data from the HTTP response stream, handling I/O errors. * * @param data buffer to use to read data * @param entityStream stream for reading the HTTP response entity * @return the number of bytes actually read or -1 if the end of the stream * has been reached */ private int readFromResponse(State state, InnerState innerState, byte[] data, InputStream entityStream) throws StopRequest { try { return entityStream.read(data); } catch (IOException ex) { logNetworkState(); mInfo.mCurrentBytes = innerState.mBytesSoFar; mDB.updateDownload(mInfo); if (cannotResume(innerState)) { String message = "while reading response: " + ex.toString() + ", can't resume interrupted download with no ETag"; throw new StopRequest(DownloaderService.STATUS_CANNOT_RESUME, message, ex); } else { throw new StopRequest(getFinalStatusForHttpError(state), "while reading response: " + ex.toString(), ex); } } } /** * Open a stream for the HTTP response entity, handling I/O errors. * * @return an InputStream to read the response entity */ private InputStream openResponseEntity(State state, HttpResponse response) throws StopRequest { try { return response.getEntity().getContent(); } catch (IOException ex) { logNetworkState(); throw new StopRequest(getFinalStatusForHttpError(state), "while getting entity: " + ex.toString(), ex); } } private void logNetworkState() { if (Constants.LOGX) { Log.i(Constants.TAG, "Net " + (mService.getNetworkAvailabilityState(mDB) == DownloaderService.NETWORK_OK ? "Up" : "Down")); } } /** * Read HTTP response headers and take appropriate action, including setting * up the destination file and updating the database. */ private void processResponseHeaders(State state, InnerState innerState, HttpResponse response) throws StopRequest { if (innerState.mContinuingDownload) { // ignore response headers on resume requests return; } readResponseHeaders(state, innerState, response); try { state.mFilename = mService.generateSaveFile(mInfo.mFileName, mInfo.mTotalBytes); } catch (DownloaderService.GenerateSaveFileError exc) { throw new StopRequest(exc.mStatus, exc.mMessage); } try { state.mStream = new FileOutputStream(state.mFilename); } catch (FileNotFoundException exc) { // make sure the directory exists File pathFile = new File(Helpers.getSaveFilePath(mService)); try { if (pathFile.mkdirs()) { state.mStream = new FileOutputStream(state.mFilename); } } catch (Exception ex) { throw new StopRequest(DownloaderService.STATUS_FILE_ERROR, "while opening destination file: " + exc.toString(), exc); } } if (Constants.LOGV) { Log.v(Constants.TAG, "writing " + mInfo.mUri + " to " + state.mFilename); } updateDatabaseFromHeaders(state, innerState); // check connectivity again now that we know the total size checkConnectivity(state); } /** * Update necessary database fields based on values of HTTP response headers * that have been read. */ private void updateDatabaseFromHeaders(State state, InnerState innerState) { mInfo.mETag = innerState.mHeaderETag; mDB.updateDownload(mInfo); } /** * Read headers from the HTTP response and store them into local state. */ private void readResponseHeaders(State state, InnerState innerState, HttpResponse response) throws StopRequest { Header header = response.getFirstHeader("Content-Disposition"); if (header != null) { innerState.mHeaderContentDisposition = header.getValue(); } header = response.getFirstHeader("Content-Location"); if (header != null) { innerState.mHeaderContentLocation = header.getValue(); } header = response.getFirstHeader("ETag"); if (header != null) { innerState.mHeaderETag = header.getValue(); } String headerTransferEncoding = null; header = response.getFirstHeader("Transfer-Encoding"); if (header != null) { headerTransferEncoding = header.getValue(); } String headerContentType = null; header = response.getFirstHeader("Content-Type"); if (header != null) { headerContentType = header.getValue(); if (!headerContentType.equals("application/vnd.android.obb")) { throw new StopRequest(DownloaderService.STATUS_FILE_DELIVERED_INCORRECTLY, "file delivered with incorrect Mime type"); } } if (headerTransferEncoding == null) { header = response.getFirstHeader("Content-Length"); if (header != null) { innerState.mHeaderContentLength = header.getValue(); // this is always set from Market long contentLength = Long.parseLong(innerState.mHeaderContentLength); if (contentLength != -1 && contentLength != mInfo.mTotalBytes) { // we're most likely on a bad wifi connection -- we should // probably // also look at the mime type --- but the size mismatch is // enough // to tell us that something is wrong here Log.e(Constants.TAG, "Incorrect file size delivered."); } } } else { // Ignore content-length with transfer-encoding - 2616 4.4 3 if (Constants.LOGVV) { Log.v(Constants.TAG, "ignoring content-length because of xfer-encoding"); } } if (Constants.LOGVV) { Log.v(Constants.TAG, "Content-Disposition: " + innerState.mHeaderContentDisposition); Log.v(Constants.TAG, "Content-Length: " + innerState.mHeaderContentLength); Log.v(Constants.TAG, "Content-Location: " + innerState.mHeaderContentLocation); Log.v(Constants.TAG, "ETag: " + innerState.mHeaderETag); Log.v(Constants.TAG, "Transfer-Encoding: " + headerTransferEncoding); } boolean noSizeInfo = innerState.mHeaderContentLength == null && (headerTransferEncoding == null || !headerTransferEncoding.equalsIgnoreCase("chunked")); if (noSizeInfo) { throw new StopRequest(DownloaderService.STATUS_HTTP_DATA_ERROR, "can't know size of download, giving up"); } } /** * Check the HTTP response status and handle anything unusual (e.g. not * 200/206). */ private void handleExceptionalStatus(State state, InnerState innerState, HttpResponse response) throws StopRequest, RetryDownload { int statusCode = response.getStatusLine().getStatusCode(); if (statusCode == 503 && mInfo.mNumFailed < Constants.MAX_RETRIES) { handleServiceUnavailable(state, response); } if (statusCode == 301 || statusCode == 302 || statusCode == 303 || statusCode == 307) { handleRedirect(state, response, statusCode); } int expectedStatus = innerState.mContinuingDownload ? 206 : DownloaderService.STATUS_SUCCESS; if (statusCode != expectedStatus) { handleOtherStatus(state, innerState, statusCode); } else { // no longer redirected state.mRedirectCount = 0; } } /** * Handle a status that we don't know how to deal with properly. */ private void handleOtherStatus(State state, InnerState innerState, int statusCode) throws StopRequest { int finalStatus; if (DownloaderService.isStatusError(statusCode)) { finalStatus = statusCode; } else if (statusCode >= 300 && statusCode < 400) { finalStatus = DownloaderService.STATUS_UNHANDLED_REDIRECT; } else if (innerState.mContinuingDownload && statusCode == DownloaderService.STATUS_SUCCESS) { finalStatus = DownloaderService.STATUS_CANNOT_RESUME; } else { finalStatus = DownloaderService.STATUS_UNHANDLED_HTTP_CODE; } throw new StopRequest(finalStatus, "http error " + statusCode); } /** * Handle a 3xx redirect status. */ private void handleRedirect(State state, HttpResponse response, int statusCode) throws StopRequest, RetryDownload { if (Constants.LOGVV) { Log.v(Constants.TAG, "got HTTP redirect " + statusCode); } if (state.mRedirectCount >= Constants.MAX_REDIRECTS) { throw new StopRequest(DownloaderService.STATUS_TOO_MANY_REDIRECTS, "too many redirects"); } Header header = response.getFirstHeader("Location"); if (header == null) { return; } if (Constants.LOGVV) { Log.v(Constants.TAG, "Location :" + header.getValue()); } String newUri; try { newUri = new URI(mInfo.mUri).resolve(new URI(header.getValue())).toString(); } catch (URISyntaxException ex) { if (Constants.LOGV) { Log.d(Constants.TAG, "Couldn't resolve redirect URI " + header.getValue() + " for " + mInfo.mUri); } throw new StopRequest(DownloaderService.STATUS_HTTP_DATA_ERROR, "Couldn't resolve redirect URI"); } ++state.mRedirectCount; state.mRequestUri = newUri; if (statusCode == 301 || statusCode == 303) { // use the new URI for all future requests (should a retry/resume be // necessary) state.mNewUri = newUri; } throw new RetryDownload(); } /** * Add headers for this download to the HTTP request to allow for resume. */ private void addRequestHeaders(InnerState innerState, HttpGet request) { if (innerState.mContinuingDownload) { if (innerState.mHeaderETag != null) { request.addHeader("If-Match", innerState.mHeaderETag); } request.addHeader("Range", "bytes=" + innerState.mBytesSoFar + "-"); } } /** * Handle a 503 Service Unavailable status by processing the Retry-After * header. */ private void handleServiceUnavailable(State state, HttpResponse response) throws StopRequest { if (Constants.LOGVV) { Log.v(Constants.TAG, "got HTTP response code 503"); } state.mCountRetry = true; Header header = response.getFirstHeader("Retry-After"); if (header != null) { try { if (Constants.LOGVV) { Log.v(Constants.TAG, "Retry-After :" + header.getValue()); } state.mRetryAfter = Integer.parseInt(header.getValue()); if (state.mRetryAfter < 0) { state.mRetryAfter = 0; } else { if (state.mRetryAfter < Constants.MIN_RETRY_AFTER) { state.mRetryAfter = Constants.MIN_RETRY_AFTER; } else if (state.mRetryAfter > Constants.MAX_RETRY_AFTER) { state.mRetryAfter = Constants.MAX_RETRY_AFTER; } state.mRetryAfter += Helpers.sRandom.nextInt(Constants.MIN_RETRY_AFTER + 1); state.mRetryAfter *= 1000; } } catch (NumberFormatException ex) { // ignored - retryAfter stays 0 in this case. } } throw new StopRequest(DownloaderService.STATUS_WAITING_TO_RETRY, "got 503 Service Unavailable, will retry later"); } /** * Send the request to the server, handling any I/O exceptions. */ private HttpResponse sendRequest(State state, AndroidHttpClient client, HttpGet request) throws StopRequest { try { return client.execute(request); } catch (IllegalArgumentException ex) { throw new StopRequest(DownloaderService.STATUS_HTTP_DATA_ERROR, "while trying to execute request: " + ex.toString(), ex); } catch (IOException ex) { logNetworkState(); throw new StopRequest(getFinalStatusForHttpError(state), "while trying to execute request: " + ex.toString(), ex); } } private int getFinalStatusForHttpError(State state) { if (mService.getNetworkAvailabilityState(mDB) != DownloaderService.NETWORK_OK) { return DownloaderService.STATUS_WAITING_FOR_NETWORK; } else if (mInfo.mNumFailed < Constants.MAX_RETRIES) { state.mCountRetry = true; return DownloaderService.STATUS_WAITING_TO_RETRY; } else { Log.w(Constants.TAG, "reached max retries for " + mInfo.mNumFailed); return DownloaderService.STATUS_HTTP_DATA_ERROR; } } /** * Prepare the destination file to receive data. If the file already exists, * we'll set up appropriately for resumption. */ private void setupDestinationFile(State state, InnerState innerState) throws StopRequest { if (state.mFilename != null) { // only true if we've already run a // thread for this download if (!Helpers.isFilenameValid(state.mFilename)) { // this should never happen throw new StopRequest(DownloaderService.STATUS_FILE_ERROR, "found invalid internal destination filename"); } // We're resuming a download that got interrupted File f = new File(state.mFilename); if (f.exists()) { long fileLength = f.length(); if (fileLength == 0) { // The download hadn't actually started, we can restart from // scratch f.delete(); state.mFilename = null; } else if (mInfo.mETag == null) { // This should've been caught upon failure f.delete(); throw new StopRequest(DownloaderService.STATUS_CANNOT_RESUME, "Trying to resume a download that can't be resumed"); } else { // All right, we'll be able to resume this download try { state.mStream = new FileOutputStream(state.mFilename, true); } catch (FileNotFoundException exc) { throw new StopRequest(DownloaderService.STATUS_FILE_ERROR, "while opening destination for resuming: " + exc.toString(), exc); } innerState.mBytesSoFar = (int) fileLength; if (mInfo.mTotalBytes != -1) { innerState.mHeaderContentLength = Long.toString(mInfo.mTotalBytes); } innerState.mHeaderETag = mInfo.mETag; innerState.mContinuingDownload = true; } } } if (state.mStream != null) { closeDestination(state); } } /** * Stores information about the completed download, and notifies the * initiating application. */ private void notifyDownloadCompleted(int status, boolean countRetry, int retryAfter, int redirectCount, boolean gotData, String filename) { updateDownloadDatabase(status, countRetry, retryAfter, redirectCount, gotData, filename); if (DownloaderService.isStatusCompleted(status)) { // TBD: send status update? } } private void updateDownloadDatabase(int status, boolean countRetry, int retryAfter, int redirectCount, boolean gotData, String filename) { mInfo.mStatus = status; mInfo.mRetryAfter = retryAfter; mInfo.mRedirectCount = redirectCount; mInfo.mLastMod = System.currentTimeMillis(); if (!countRetry) { mInfo.mNumFailed = 0; } else if (gotData) { mInfo.mNumFailed = 1; } else { mInfo.mNumFailed++; } mDB.updateDownload(mInfo); } }