Java tutorial
/* Viewer for Khan Academy Copyright (C) 2012 Concentric Sky, Inc. This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>. */ package com.concentricsky.android.khanacademy.data.remote; import java.io.IOException; import java.net.MalformedURLException; import java.sql.SQLException; import java.util.List; import java.util.Locale; import oauth.signpost.OAuthConsumer; import oauth.signpost.exception.OAuthCommunicationException; import oauth.signpost.exception.OAuthExpectationFailedException; import oauth.signpost.exception.OAuthMessageSignerException; import org.apache.http.client.ClientProtocolException; import org.apache.http.client.HttpClient; import org.apache.http.client.HttpResponseException; import org.apache.http.client.ResponseHandler; import org.apache.http.client.methods.HttpPost; import org.apache.http.impl.client.BasicResponseHandler; import org.apache.http.impl.client.DefaultHttpClient; import android.os.AsyncTask; import com.concentricsky.android.khanacademy.data.KADataService; import com.concentricsky.android.khanacademy.data.db.Badge; import com.concentricsky.android.khanacademy.data.db.User; import com.concentricsky.android.khanacademy.data.db.UserVideo; import com.concentricsky.android.khanacademy.data.db.Video; import com.concentricsky.android.khanacademy.util.Log; import com.fasterxml.jackson.annotation.JsonIgnoreProperties; import com.fasterxml.jackson.databind.ObjectMapper; import com.j256.ormlite.dao.Dao; class VideoProgressPostTask extends AsyncTask<UserVideo, Void, User> { public static final String LOG_TAG = VideoProgressPostTask.class.getSimpleName(); private String url = "http://www.khanacademy.org/api/v1/user/videos/%s/log"; private KADataService dataService; private OAuthConsumer consumer; public VideoProgressPostTask(KADataService dataService) { this.dataService = dataService; } @Override protected User doInBackground(UserVideo... params) { /* * * A Giant waste of time deserves a Giant comment block. * * To properly sign post requests, we need to send the payload as a querystring. * * Some alternatives that did not work: * Set the data as params onto the request * Set the data as params onto the OAuthConsumer * Set the data onto the request as headers (?!) * Write the data into the request entity * * Tried all of those before and after signing, and with various Accept / Content-Type headers. * * This work-around comes from a comment in this bug report related to HttpURLConnection: * http://code.google.com/p/oauth-signpost/issues/detail?id=15 * * According to the other comments, this should not be necessary when using the apache http * library, as we do get a chance to sign the request after specifying content but before * opening the connection. However, I had no luck. * */ UserVideo userVideo = params[0]; String videoId = null; User user = null; Dao<User, String> userDao = null; Dao<Video, String> videoDao = null; try { user = userVideo.getUser(); userDao = dataService.getHelper().getUserDao(); userDao.refresh(user); consumer = dataService.getAPIAdapter().getConsumer(user); videoDao = dataService.getHelper().getVideoDao(); Video video = videoDao.queryForFirst( videoDao.queryBuilder().where().eq("readable_id", userVideo.getVideo_id()).prepare()); videoId = video.getYoutube_id(); url = String.format(url, videoId); } catch (SQLException e) { // Fail silently when trying to post progress updates. e.printStackTrace(); return null; } final User existingUser = user; final UserVideo existingUserVideo = userVideo; VideoProgressUpdate payload = new VideoProgressUpdate(userVideo); VideoProgressResult result = remoteFetch(payload); if (result != null) { ActionResults results = result.getAction_results(); // Update User and UserVideo, save, and fire callbacks. // User. User returnedUser = results.getUser_data(); // The returned user object is more current than the existing (total seconds watched at the least). // Set onto the new user the fields that won't appear in the response. Nickname (and hence id) is already correct. returnedUser.setToken(existingUser.getToken()); returnedUser.setSecret(existingUser.getSecret()); try { dataService.getHelper().getUserDao().update(returnedUser); } catch (SQLException e) { e.printStackTrace(); } // Badges. try { List<Badge> badges = results.getBadges_earned().getBadges(); // DEBUG // for (Badge b : badges) { // try { // Log.d(LOG_TAG, new ObjectMapper().writeValueAsString(b)); // } catch (JsonProcessingException e) { // e.printStackTrace(); // } // } // It's possible to get a response with multiple earned badges. In fact, this always happens // when the user earns "Awesome Listener" for watching an hour of a topic; the user also earns // a "Great Listener" for 30 minutes and a "Nice Listener" for 15 minutes at the same time. // We don't want a 10-minute badge-toaststravaganza, so just toast the last one listed. if (badges != null && badges.size() > 0) { Badge b = badges.get(badges.size() - 1); dataService.getAPIAdapter().doBadgeEarned(b); } } catch (NullPointerException e) { // No badges were earned. } // Now UserVideo. UserVideo returnedVideo = results.getUser_video(); // Again, the returned object is fresher than our existing one. returnedVideo.setId(existingUserVideo.getId()); try { dataService.getHelper().getUserVideoDao().update(returnedVideo); } catch (SQLException e) { e.printStackTrace(); } // Do the user update here, after the UserVideo has been saved. return returnedUser; } else { Log.e(LOG_TAG, "null result in postVideoProgress"); return null; } } private VideoProgressResult remoteFetch(VideoProgressUpdate update) { VideoProgressResult result = null; String q = String.format(Locale.US, "last_second_watched=%d&seconds_watched=%d", update.getLast_second_watched(), update.getSeconds_watched()); url = String.format("%s?%s", url, q); Log.d(KAAPIAdapter.LOG_TAG, "posting video progress: " + url); // Use this! The response is chunked, so don't try to get the Content-Length and read a buffer of that length. // However, the response is small, so it isn't a big deal that this handler blocks until it's done. ResponseHandler<String> h = new BasicResponseHandler(); HttpClient httpClient = new DefaultHttpClient(); HttpPost request = new HttpPost(url); ObjectMapper mapper = new ObjectMapper(); try { consumer.sign(request); String response = httpClient.execute(request, h); result = mapper.readValue(response, VideoProgressResult.class); // DEBUG // User ud = result.action_results.user_data; // UserVideo uv = result.action_results.user_video; // if (result.action_results.badges_earned != null) { // List<Badge> badges = result.action_results.badges_earned.getBadges(); // if (badges != null) { // Log.d(KAAPIAdapter.LOG_TAG, "Badges: "); // for (Badge b : badges) { // Log.d(KAAPIAdapter.LOG_TAG, " " + b.getDescription() + " (" + b.getPoints() + " points)"); // } // } else { // Log.d(KAAPIAdapter.LOG_TAG, "badges was null"); // } // } else { // Log.d(KAAPIAdapter.LOG_TAG, "badges was null"); // } // // Log.d(KAAPIAdapter.LOG_TAG, "url was " + url); // Log.d(KAAPIAdapter.LOG_TAG, "got data for " + ud.getNickname() + ", video points: " + uv.getPoints()); } catch (MalformedURLException e) { e.printStackTrace(); } catch (OAuthMessageSignerException e) { e.printStackTrace(); } catch (OAuthExpectationFailedException e) { e.printStackTrace(); } catch (OAuthCommunicationException e) { e.printStackTrace(); } catch (HttpResponseException e) { e.printStackTrace(); } catch (ClientProtocolException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } return result; } @JsonIgnoreProperties(ignoreUnknown = true) public static class VideoProgressUpdate { int last_second_watched; int seconds_watched; public VideoProgressUpdate(UserVideo userVideo) { last_second_watched = userVideo.getLast_second_watched(); seconds_watched = userVideo.getSeconds_watched(); } /** * @return the last_second_watched */ public int getLast_second_watched() { return last_second_watched; } /** * @param last_second_watched the last_second_watched to set */ public void setLast_second_watched(int last_second_watched) { this.last_second_watched = last_second_watched; } /** * @return the seconds_watched */ public int getSeconds_watched() { return seconds_watched; } /** * @param seconds_watched the seconds_watched to set */ public void setSeconds_watched(int seconds_watched) { this.seconds_watched = seconds_watched; } } // This came as 'action_results': {... 'badges_earned': { 'badges': [ /* in here */ ] } ... } . /** * When ActionResults contain some badges earned, they are wrapped in this object. */ @JsonIgnoreProperties(ignoreUnknown = true) public static class BadgesEarned { List<Badge> badges; public List<Badge> getBadges() { return badges; } public void setBadges(List<Badge> badges) { this.badges = badges; } } @JsonIgnoreProperties(ignoreUnknown = true) public static class ActionResults { User user_data; UserVideo user_video; BadgesEarned badges_earned; public User getUser_data() { return user_data; } public void setUser_data(User user_data) { this.user_data = user_data; } public UserVideo getUser_video() { return user_video; } public void setUser_video(UserVideo user_video) { this.user_video = user_video; } public BadgesEarned getBadges_earned() { return badges_earned; } public void setBadges_earned(BadgesEarned badges_earned) { this.badges_earned = badges_earned; } // tutorial_node_progress // user_info_html } @JsonIgnoreProperties(ignoreUnknown = true) public static class VideoProgressResult { ActionResults action_results; public ActionResults getAction_results() { return action_results; } public void setAction_results(ActionResults action_results) { this.action_results = action_results; } // time_watched } }