test123/GTaskSyncService.java

/*
 * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
 *
 * 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 net.micode.notes.gtask.remote;
/*
Service是在一段不定的时间运行在后台，不和用户交互的应用组件
主要方法：\n * private void startSync()  启动一个同步工作
private void cancelSync() 取消同步
public void onCreate()
 public int onStartCommand(Intent intent, int flags, int startId)  service生命周期的组成部分，相当于重启service（比如在被暂停之后），而不是创建一个新的service
 public void onLowMemory()  在没有内存的情况下如果存在service则结束掉这的service
 public IBinder onBind()
 public void sendBroadcast(String msg)   发送同步的相关通知
 public static void startSync(Activity activity)
 public static void cancelSync(Context context)
 public static boolean isSyncing()  判读是否在进行同步
  public static String getProgressString()  获取当前进度的信息
  */
import android.app.Activity;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.os.IBinder;

public class GTaskSyncService extends Service {
    public final static String ACTION_STRING_NAME = "sync_action_type";

    public final static int ACTION_START_SYNC = 0;

    public final static int ACTION_CANCEL_SYNC = 1;

    public final static int ACTION_INVALID = 2;

    public final static String GTASK_SERVICE_BROADCAST_NAME = "net.micode.notes.gtask.remote.gtask_sync_service";

    public final static String GTASK_SERVICE_BROADCAST_IS_SYNCING = "isSyncing";

    public final static String GTASK_SERVICE_BROADCAST_PROGRESS_MSG = "progressMsg";

    private static GTaskASyncTask mSyncTask = null;

    private static String mSyncProgress = "";
    //开始同步的工作
    private void startSync() {
        if (mSyncTask == null) {
            mSyncTask = new GTaskASyncTask(this, new GTaskASyncTask.OnCompleteListener() {
                public void onComplete() {
                    mSyncTask = null;
                    sendBroadcast("");
                    stopSelf();
                }
            });
            sendBroadcast("");
            mSyncTask.execute();//这个函数是让任务是以单线程队列方式或线程池队列方式运行
        }
    }

    private void cancelSync() {
        if (mSyncTask != null) {
            mSyncTask.cancelSync();
        }
    }

    @Override
    public void onCreate() {//初始化一个service
        mSyncTask = null;
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Bundle bundle = intent.getExtras();
        if (bundle != null && bundle.containsKey(ACTION_STRING_NAME)) {
            switch (bundle.getInt(ACTION_STRING_NAME, ACTION_INVALID)) {
            //两种情况，开始同步或者取消同步
                case ACTION_START_SYNC:
                    startSync();
                    break;
                case ACTION_CANCEL_SYNC:
                    cancelSync();
                    break;
                default:
                    break;
            }
            return START_STICKY;//等待新的intent来是这个service继续运行
        }
        return super.onStartCommand(intent, flags, startId);
    }

    @Override
    public void onLowMemory() {
        if (mSyncTask != null) {
            mSyncTask.cancelSync();
        }
    }

    public IBinder onBind(Intent intent) {
        return null;
    }

    public void sendBroadcast(String msg) {
        mSyncProgress = msg;
        Intent intent = new Intent(GTASK_SERVICE_BROADCAST_NAME);//创建一个新的Intent
        intent.putExtra(GTASK_SERVICE_BROADCAST_IS_SYNCING, mSyncTask != null);//附加intent中相应参数的值
        intent.putExtra(GTASK_SERVICE_BROADCAST_PROGRESS_MSG, msg);
        sendBroadcast(intent);//发送通知
    }

    public static void startSync(Activity activity) {//执行一个service，service的内容里的同步动作即为开始同步
        GTaskManager.getInstance().setActivityContext(activity);
        Intent intent = new Intent(activity, GTaskSyncService.class);
        intent.putExtra(GTaskSyncService.ACTION_STRING_NAME, GTaskSyncService.ACTION_START_SYNC);
        activity.startService(intent);
    }

    public static void cancelSync(Context context) {//执行一个service，service的内容里的同步动作即为取消同步
        Intent intent = new Intent(context, GTaskSyncService.class);
        intent.putExtra(GTaskSyncService.ACTION_STRING_NAME, GTaskSyncService.ACTION_CANCEL_SYNC);
        context.startService(intent);
    }

    public static boolean isSyncing() {
        return mSyncTask != null;
    }

    public static String getProgressString() {
        return mSyncProgress;
    }
}