Java tutorial
/* * Copyright 2011 Google Inc. * * 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. */ /* * Modifications: * - Imported from IOSched * - Changed package name * - Changed parsed data * - Removed SharedPreferences and versions management * - Removed the ResultReceiver */ package ca.mudar.mtlaucasou.services; import ca.mudar.mtlaucasou.io.LocalExecutor; import ca.mudar.mtlaucasou.io.RemoteExecutor; import ca.mudar.mtlaucasou.io.RemotePlacemarksHandler; import ca.mudar.mtlaucasou.provider.PlacemarkContract.ConditionedPlaces; import ca.mudar.mtlaucasou.provider.PlacemarkContract.EmergencyHostels; import ca.mudar.mtlaucasou.provider.PlacemarkContract.FireHalls; import ca.mudar.mtlaucasou.provider.PlacemarkContract.SpvmStations; import ca.mudar.mtlaucasou.provider.PlacemarkContract.WaterSupplies; import ca.mudar.mtlaucasou.utils.Const; import ca.mudar.mtlaucasou.utils.Const.KmlLocalAssets; import org.apache.http.Header; import org.apache.http.HeaderElement; import org.apache.http.HttpEntity; import org.apache.http.HttpRequest; import org.apache.http.HttpRequestInterceptor; import org.apache.http.HttpResponse; import org.apache.http.HttpResponseInterceptor; import org.apache.http.client.HttpClient; import org.apache.http.entity.HttpEntityWrapper; import org.apache.http.impl.client.DefaultHttpClient; import org.apache.http.params.BasicHttpParams; import org.apache.http.params.HttpConnectionParams; import org.apache.http.params.HttpParams; import org.apache.http.params.HttpProtocolParams; import org.apache.http.protocol.HttpContext; import android.app.IntentService; import android.app.Service; import android.content.ContentResolver; import android.content.Context; import android.content.Intent; import android.content.pm.PackageInfo; import android.content.pm.PackageManager; import android.content.pm.PackageManager.NameNotFoundException; import android.os.Bundle; import android.os.ResultReceiver; import android.text.format.DateUtils; import android.util.Log; import java.io.IOException; import java.io.InputStream; import java.util.zip.GZIPInputStream; /** * Background {@link Service} that synchronizes data living in * {@link PlacemarkProvider}. Reads data from remote sources */ public class SyncService extends IntentService { private static final String TAG = "SyncService"; public static final String EXTRA_STATUS_RECEIVER = "ca.mudar.mtlaucasou.extra.STATUS_RECEIVER"; public static final int STATUS_RUNNING = 0x1; public static final int STATUS_ERROR = 0x2; public static final int STATUS_FINISHED = 0x3; private static final int SECOND_IN_MILLIS = (int) DateUtils.SECOND_IN_MILLIS; private static final String HEADER_ACCEPT_ENCODING = "Accept-Encoding"; private static final String ENCODING_GZIP = "gzip"; private LocalExecutor mLocalExecutor; private RemoteExecutor mRemoteExecutor; public SyncService() { super(TAG); } @Override public void onCreate() { super.onCreate(); final HttpClient httpClient = getHttpClient(this); final ContentResolver resolver = getContentResolver(); mLocalExecutor = new LocalExecutor(getResources(), resolver); mRemoteExecutor = new RemoteExecutor(httpClient, resolver); } @Override protected void onHandleIntent(Intent intent) { final ResultReceiver receiver = intent.getParcelableExtra(EXTRA_STATUS_RECEIVER); if (receiver != null) { receiver.send(STATUS_RUNNING, Bundle.EMPTY); } final Context context = this; try { // Bulk of sync work, performed by executing several fetches from // local and online sources. final long startLocal = System.currentTimeMillis(); /** * Five Assets files to load, so progress goes by 20%. */ Bundle bundle = new Bundle(); bundle.putInt(Const.KEY_BUNDLE_PROGRESS_INCREMENT, 20); // Parse values from local cache first, since SecurityServices copy // or network might be down. receiver.send(STATUS_RUNNING, bundle); mLocalExecutor.execute(context, KmlLocalAssets.FIRE_HALLS, new RemotePlacemarksHandler(FireHalls.CONTENT_URI, true)); receiver.send(STATUS_RUNNING, bundle); mLocalExecutor.execute(context, KmlLocalAssets.SPVM_STATIONS, new RemotePlacemarksHandler(SpvmStations.CONTENT_URI, true)); receiver.send(STATUS_RUNNING, bundle); mLocalExecutor.execute(context, KmlLocalAssets.WATER_SUPPLIES, new RemotePlacemarksHandler(WaterSupplies.CONTENT_URI)); receiver.send(STATUS_RUNNING, bundle); mLocalExecutor.execute(context, KmlLocalAssets.EMERGENCY_HOSTELS, new RemotePlacemarksHandler(EmergencyHostels.CONTENT_URI)); receiver.send(STATUS_RUNNING, bundle); mLocalExecutor.execute(context, KmlLocalAssets.CONDITIONED_PLACES, new RemotePlacemarksHandler(ConditionedPlaces.CONTENT_URI)); Log.v(TAG, "Sync duration: " + (System.currentTimeMillis() - startLocal) + " ms"); // TODO: update data from remote source // Always hit remote SecurityServices for any updates // final long startRemote = System.currentTimeMillis(); // mRemoteExecutor // .executeGet(WORKSHEETS_URL, new // RemoteSecurityServicesHandler(mRemoteExecutor)); // Log.d(TAG, "remote sync took " + (System.currentTimeMillis() - // startRemote) + "ms"); } catch (Exception e) { Log.e(TAG, e.getMessage()); if (receiver != null) { /** * Pass back error to surface listener */ final Bundle bundle = new Bundle(); bundle.putString(Intent.EXTRA_TEXT, e.toString()); receiver.send(STATUS_ERROR, bundle); } } if (receiver != null) { receiver.send(STATUS_FINISHED, Bundle.EMPTY); } } /** * Generate and return a {@link HttpClient} configured for general use, * including setting an application-specific user-agent string. */ public static HttpClient getHttpClient(Context context) { final HttpParams params = new BasicHttpParams(); // Use generous timeouts for slow mobile networks HttpConnectionParams.setConnectionTimeout(params, 20 * SECOND_IN_MILLIS); HttpConnectionParams.setSoTimeout(params, 20 * SECOND_IN_MILLIS); HttpConnectionParams.setSocketBufferSize(params, 8192); HttpProtocolParams.setUserAgent(params, buildUserAgent(context)); final DefaultHttpClient client = new DefaultHttpClient(params); client.addRequestInterceptor(new HttpRequestInterceptor() { public void process(HttpRequest request, HttpContext context) { // Add header to accept gzip content if (!request.containsHeader(HEADER_ACCEPT_ENCODING)) { request.addHeader(HEADER_ACCEPT_ENCODING, ENCODING_GZIP); } } }); client.addResponseInterceptor(new HttpResponseInterceptor() { public void process(HttpResponse response, HttpContext context) { // Inflate any responses compressed with gzip final HttpEntity entity = response.getEntity(); final Header encoding = entity.getContentEncoding(); if (encoding != null) { for (HeaderElement element : encoding.getElements()) { if (element.getName().equalsIgnoreCase(ENCODING_GZIP)) { response.setEntity(new InflatingEntity(response.getEntity())); break; } } } } }); return client; } /** * Build and return a user-agent string that can identify this application * to remote servers. Contains the package name and version code. */ private static String buildUserAgent(Context context) { try { final PackageManager manager = context.getPackageManager(); final PackageInfo info = manager.getPackageInfo(context.getPackageName(), 0); // Some APIs require "(gzip)" in the user-agent string. return info.packageName + "/" + info.versionName + " (" + info.versionCode + ") (gzip)"; } catch (NameNotFoundException e) { Log.e(TAG, e.getMessage()); return null; } } /** * Simple {@link HttpEntityWrapper} that inflates the wrapped * {@link HttpEntity} by passing it through {@link GZIPInputStream}. */ private static class InflatingEntity extends HttpEntityWrapper { public InflatingEntity(HttpEntity wrapped) { super(wrapped); } @Override public InputStream getContent() throws IOException { return new GZIPInputStream(wrappedEntity.getContent()); } @Override public long getContentLength() { return -1; } } }