Java tutorial
/* * Copyright 2014 Google Inc. All rights reserved. * * 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.samples.apps.iosched.sync.userdata.util; import android.content.ContentProviderOperation; import android.content.Context; import android.content.OperationApplicationException; import android.os.RemoteException; import android.util.Log; import com.google.samples.apps.iosched.provider.ScheduleContract; import com.google.samples.apps.iosched.sync.userdata.UserAction; import com.google.gson.JsonArray; import com.google.gson.JsonObject; import com.google.gson.JsonPrimitive; import com.google.gson.stream.JsonReader; import java.io.IOException; import java.io.StringReader; import java.util.ArrayList; import java.util.List; import static com.google.samples.apps.iosched.util.LogUtils.makeLogTag; public class UserActionHelper { private static final String TAG = makeLogTag(UserActionHelper.class); static public void updateContentProvider(Context context, List<UserAction> userActions, String account) { ArrayList<ContentProviderOperation> batch = new ArrayList<ContentProviderOperation>(); for (UserAction action : userActions) { batch.add(createUpdateOperation(context, action, account)); } try { context.getContentResolver().applyBatch(ScheduleContract.CONTENT_AUTHORITY, batch); } catch (RemoteException e) { Log.e(TAG, "Could not apply operations", e); } catch (OperationApplicationException e) { Log.e(TAG, "Could not apply operations", e); } } static private ContentProviderOperation createUpdateOperation(Context context, UserAction action, String account) { if (action.type == UserAction.TYPE.ADD_STAR) { return ContentProviderOperation .newInsert(ScheduleContract.addOverrideAccountName(ScheduleContract.MySchedule.CONTENT_URI, account)) .withValue(ScheduleContract.MySchedule.MY_SCHEDULE_DIRTY_FLAG, "0") .withValue(ScheduleContract.MySchedule.SESSION_ID, action.sessionId).build(); } else { return ContentProviderOperation .newDelete(ScheduleContract.addOverrideAccountName(ScheduleContract.MySchedule.CONTENT_URI, account)) .withSelection( ScheduleContract.MySchedule.SESSION_ID + " = ? AND " + ScheduleContract.MySchedule.MY_SCHEDULE_ACCOUNT_NAME + " = ? ", new String[] { action.sessionId, account }) .build(); } } public static String serializeUserActions(List<UserAction> actions) { JsonArray array = new JsonArray(); for (UserAction action : actions) { JsonObject obj = new JsonObject(); obj.add("type", new JsonPrimitive(action.type.name())); obj.add("id", new JsonPrimitive(action.sessionId)); array.add(obj); } return array.toString(); } public static List<UserAction> deserializeUserActions(String str) { try { ArrayList<UserAction> actions = new ArrayList<UserAction>(); JsonReader reader = new JsonReader(new StringReader(str)); reader.beginArray(); while (reader.hasNext()) { reader.beginObject(); UserAction action = new UserAction(); while (reader.hasNext()) { String key = reader.nextName(); if ("type".equals(key)) { action.type = UserAction.TYPE.valueOf(reader.nextString()); } else if ("id".equals(key)) { action.sessionId = reader.nextString(); } else { throw new RuntimeException("Invalid key " + key + " in serialized UserAction: " + str); } } reader.endObject(); actions.add(action); } reader.endArray(); return actions; } catch (IOException ex) { throw new RuntimeException("Error deserializing UserActions: " + str, ex); } } }