at.bitfire.davdroid.mirakel.syncadapter.DavSyncAdapter.java Source code

Java tutorial

Introduction

Here is the source code for at.bitfire.davdroid.mirakel.syncadapter.DavSyncAdapter.java

Source

/*******************************************************************************
 * Copyright (c) 2014 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
 * 
 * Contributors:
 *     Richard Hirner (bitfire web engineering) - initial API and implementation
 ******************************************************************************/
package at.bitfire.davdroid.mirakel.syncadapter;

import java.io.Closeable;
import java.io.IOException;
import java.util.Map;
import java.util.concurrent.locks.ReentrantReadWriteLock;

import lombok.Getter;

import org.apache.http.HttpStatus;

import android.accounts.Account;
import android.accounts.AccountManager;
import android.content.AbstractThreadedSyncAdapter;
import android.content.ContentProviderClient;
import android.content.ContentResolver;
import android.content.Context;
import android.content.SharedPreferences;
import android.content.SyncResult;
import android.os.AsyncTask;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.provider.Settings;
import android.util.Log;
import at.bitfire.davdroid.mirakel.Constants;
import at.bitfire.davdroid.mirakel.resource.LocalCollection;
import at.bitfire.davdroid.mirakel.resource.LocalStorageException;
import at.bitfire.davdroid.mirakel.resource.RemoteCollection;
import at.bitfire.davdroid.mirakel.webdav.DavException;
import at.bitfire.davdroid.mirakel.webdav.DavHttpClient;
import at.bitfire.davdroid.mirakel.webdav.HttpException;
import ch.boye.httpclientandroidlib.impl.client.CloseableHttpClient;

public abstract class DavSyncAdapter extends AbstractThreadedSyncAdapter implements Closeable {
    private final static String TAG = "davdroid.DavSyncAdapter";

    @Getter
    private static String androidID;

    protected AccountManager accountManager;

    /* We use one static httpClient for
     *   - all sync adapters  (CalendarsSyncAdapter, ContactsSyncAdapter)
     *   - and all threads (= accounts) of each sync adapter
     * so that HttpClient's threaded pool management can do its best.
     */
    protected static CloseableHttpClient httpClient;

    /* One static read/write lock pair for the static httpClient:
     *    Use the READ  lock when httpClient will only be called (to prevent it from being unset while being used).
     *    Use the WRITE lock when httpClient will be modified (set/unset). */
    private final static ReentrantReadWriteLock httpClientLock = new ReentrantReadWriteLock();

    public DavSyncAdapter(Context context) {
        super(context, true);

        synchronized (this) {
            if (androidID == null)
                androidID = Settings.Secure.getString(context.getContentResolver(), Settings.Secure.ANDROID_ID);
        }

        accountManager = AccountManager.get(context);
    }

    @Override
    public void close() {
        Log.d(TAG, "Closing httpClient");

        // may be called from a GUI thread, so we need an AsyncTask
        new AsyncTask<Void, Void, Void>() {
            @Override
            protected Void doInBackground(Void... params) {
                try {
                    httpClientLock.writeLock().lock();
                    if (httpClient != null) {
                        httpClient.close();
                        httpClient = null;
                    }
                    httpClientLock.writeLock().unlock();
                } catch (IOException e) {
                    Log.w(TAG, "Couldn't close HTTP client", e);
                }
                return null;
            }
        }.execute();
    }

    protected abstract Map<LocalCollection<?>, RemoteCollection<?>> getSyncPairs(Account account,
            ContentProviderClient provider);

    @Override
    public void onPerformSync(Account account, Bundle extras, String authority, ContentProviderClient provider,
            SyncResult syncResult) {
        Log.i(TAG, "Performing sync for authority " + authority);
        // set class loader for iCal4j ResourceLoader
        Thread.currentThread().setContextClassLoader(getContext().getClassLoader());

        // create httpClient, if necessary
        httpClientLock.writeLock().lock();
        if (httpClient == null) {
            Log.d(TAG, "Creating new DavHttpClient");
            SharedPreferences settings = PreferenceManager.getDefaultSharedPreferences(getContext());
            httpClient = DavHttpClient.create(settings.getBoolean(Constants.SETTING_DISABLE_COMPRESSION, false),
                    settings.getBoolean(Constants.SETTING_NETWORK_LOGGING, false));
        }

        // prevent httpClient shutdown until we're ready by holding a read lock
        // acquiring read lock before releasing write lock will downgrade the write lock to a read lock
        httpClientLock.readLock().lock();
        httpClientLock.writeLock().unlock();

        // TODO use VCard 4.0 if possible
        AccountSettings accountSettings = new AccountSettings(getContext(), account);
        Log.d(TAG, "Server supports VCard version " + accountSettings.getAddressBookVCardVersion());

        try {
            // get local <-> remote collection pairs
            Map<LocalCollection<?>, RemoteCollection<?>> syncCollections = getSyncPairs(account, provider);
            if (syncCollections == null)
                Log.i(TAG, "Nothing to synchronize");
            else
                try {
                    for (Map.Entry<LocalCollection<?>, RemoteCollection<?>> entry : syncCollections.entrySet())
                        new SyncManager(entry.getKey(), entry.getValue())
                                .synchronize(extras.containsKey(ContentResolver.SYNC_EXTRAS_MANUAL), syncResult);

                } catch (DavException ex) {
                    syncResult.stats.numParseExceptions++;
                    Log.e(TAG, "Invalid DAV response", ex);
                } catch (HttpException ex) {
                    if (ex.getCode() == HttpStatus.SC_UNAUTHORIZED) {
                        Log.e(TAG, "HTTP Unauthorized " + ex.getCode(), ex);
                        syncResult.stats.numAuthExceptions++;
                    } else if (ex.isClientError()) {
                        Log.e(TAG, "Hard HTTP error " + ex.getCode(), ex);
                        syncResult.stats.numParseExceptions++;
                    } else {
                        Log.w(TAG, "Soft HTTP error " + ex.getCode() + " (Android will try again later)", ex);
                        syncResult.stats.numIoExceptions++;
                    }

                } catch (LocalStorageException ex) {
                    syncResult.databaseError = true;
                    Log.e(TAG, "Local storage (content provider) exception", ex);
                } catch (IOException ex) {
                    syncResult.stats.numIoExceptions++;
                    Log.e(TAG, "I/O error (Android will try again later)", ex);
                }
        } finally {
            // allow httpClient shutdown
            httpClientLock.readLock().unlock();
        }

        Log.i(TAG, "Sync complete for " + authority);
    }

}