Java tutorial
/* * Copyright 2013 2015 Ricki Hirner (bitfire web engineering). * All rights reserved. This program and the accompanying materials * are made available under the terms of the GNU Public License v3.0 * which accompanies this distribution, and is available at * http://www.gnu.org/licenses/gpl.html */ package at.bitfire.davdroid.syncadapter; import android.accounts.Account; import android.content.Context; import android.content.SyncResult; import android.os.Bundle; import org.apache.commons.codec.Charsets; import org.apache.commons.lang3.StringUtils; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.InputStream; import java.nio.charset.Charset; import java.util.HashMap; import java.util.LinkedList; import java.util.List; import java.util.logging.Level; import at.bitfire.dav4android.DavCalendar; import at.bitfire.dav4android.DavResource; import at.bitfire.dav4android.exception.DavException; import at.bitfire.dav4android.exception.HttpException; import at.bitfire.dav4android.property.CalendarData; import at.bitfire.dav4android.property.GetCTag; import at.bitfire.dav4android.property.GetContentType; import at.bitfire.dav4android.property.GetETag; import at.bitfire.davdroid.AccountSettings; import at.bitfire.davdroid.App; import at.bitfire.davdroid.ArrayUtils; import at.bitfire.davdroid.Constants; import at.bitfire.davdroid.InvalidAccountException; import at.bitfire.davdroid.R; import at.bitfire.davdroid.resource.LocalResource; import at.bitfire.davdroid.resource.LocalTask; import at.bitfire.davdroid.resource.LocalTaskList; import at.bitfire.ical4android.CalendarStorageException; import at.bitfire.ical4android.InvalidCalendarException; import at.bitfire.ical4android.Task; import at.bitfire.ical4android.TaskProvider; import lombok.Cleanup; import okhttp3.HttpUrl; import okhttp3.MediaType; import okhttp3.RequestBody; import okhttp3.ResponseBody; public class TasksSyncManager extends SyncManager { protected static final int MAX_MULTIGET = 30; final protected TaskProvider provider; public TasksSyncManager(Context context, Account account, AccountSettings settings, Bundle extras, String authority, TaskProvider provider, SyncResult result, LocalTaskList taskList) throws InvalidAccountException { super(context, account, settings, extras, authority, result, "taskList/" + taskList.getId()); this.provider = provider; localCollection = taskList; } @Override protected int notificationId() { return Constants.NOTIFICATION_TASK_SYNC; } @Override protected String getSyncErrorTitle() { return context.getString(R.string.sync_error_tasks, account.name); } @Override protected void prepare() { collectionURL = HttpUrl.parse(localTaskList().getSyncId()); davCollection = new DavCalendar(httpClient, collectionURL); } @Override protected void queryCapabilities() throws DavException, IOException, HttpException { davCollection.propfind(0, GetCTag.NAME); } @Override protected RequestBody prepareUpload(LocalResource resource) throws IOException, CalendarStorageException { LocalTask local = (LocalTask) resource; App.log.log(Level.FINE, "Preparing upload of task " + local.getFileName(), local.getTask()); ByteArrayOutputStream os = new ByteArrayOutputStream(); local.getTask().write(os); return RequestBody.create(DavCalendar.MIME_ICALENDAR, os.toByteArray()); } @Override protected void listRemote() throws IOException, HttpException, DavException { // fetch list of remote VTODOs and build hash table to index file name davCalendar().calendarQuery("VTODO", null, null); remoteResources = new HashMap<>(davCollection.members.size()); for (DavResource vCard : davCollection.members) { String fileName = vCard.fileName(); App.log.fine("Found remote VTODO: " + fileName); remoteResources.put(fileName, vCard); } } @Override protected void downloadRemote() throws IOException, HttpException, DavException, CalendarStorageException { App.log.info("Downloading " + toDownload.size() + " tasks (" + MAX_MULTIGET + " at once)"); // download new/updated iCalendars from server for (DavResource[] bunch : ArrayUtils.partition(toDownload.toArray(new DavResource[toDownload.size()]), MAX_MULTIGET)) { if (Thread.interrupted()) return; App.log.info("Downloading " + StringUtils.join(bunch, ", ")); if (bunch.length == 1) { // only one contact, use GET DavResource remote = bunch[0]; ResponseBody body = remote.get("text/calendar"); // CalDAV servers MUST return ETag on GET [https://tools.ietf.org/html/rfc4791#section-5.3.4] GetETag eTag = (GetETag) remote.properties.get(GetETag.NAME); if (eTag == null || StringUtils.isEmpty(eTag.eTag)) throw new DavException("Received CalDAV GET response without ETag for " + remote.location); Charset charset = Charsets.UTF_8; MediaType contentType = body.contentType(); if (contentType != null) charset = contentType.charset(Charsets.UTF_8); @Cleanup InputStream stream = body.byteStream(); processVTodo(remote.fileName(), eTag.eTag, stream, charset); } else { // multiple contacts, use multi-get List<HttpUrl> urls = new LinkedList<>(); for (DavResource remote : bunch) urls.add(remote.location); davCalendar().multiget(urls.toArray(new HttpUrl[urls.size()])); // process multiget results for (DavResource remote : davCollection.members) { String eTag; GetETag getETag = (GetETag) remote.properties.get(GetETag.NAME); if (getETag != null) eTag = getETag.eTag; else throw new DavException("Received multi-get response without ETag"); Charset charset = Charsets.UTF_8; GetContentType getContentType = (GetContentType) remote.properties.get(GetContentType.NAME); if (getContentType != null && getContentType.type != null) { MediaType type = MediaType.parse(getContentType.type); if (type != null) charset = type.charset(Charsets.UTF_8); } CalendarData calendarData = (CalendarData) remote.properties.get(CalendarData.NAME); if (calendarData == null || calendarData.iCalendar == null) throw new DavException("Received multi-get response without address data"); @Cleanup InputStream stream = new ByteArrayInputStream(calendarData.iCalendar.getBytes()); processVTodo(remote.fileName(), eTag, stream, charset); } } } } // helpers private LocalTaskList localTaskList() { return ((LocalTaskList) localCollection); } private DavCalendar davCalendar() { return (DavCalendar) davCollection; } private void processVTodo(String fileName, String eTag, InputStream stream, Charset charset) throws IOException, CalendarStorageException { Task[] tasks; try { tasks = Task.fromStream(stream, charset); } catch (InvalidCalendarException e) { App.log.log(Level.SEVERE, "Received invalid iCalendar, ignoring", e); return; } if (tasks.length == 1) { Task newData = tasks[0]; // update local task, if it exists LocalTask localTask = (LocalTask) localResources.get(fileName); if (localTask != null) { App.log.info("Updating " + fileName + " in local tasklist"); localTask.setETag(eTag); localTask.update(newData); syncResult.stats.numUpdates++; } else { App.log.info("Adding " + fileName + " to local task list"); localTask = new LocalTask(localTaskList(), newData, fileName, eTag); localTask.add(); syncResult.stats.numInserts++; } } else App.log.severe("Received VCALENDAR with not exactly one VTODO; ignoring " + fileName); } }