我们一直致力于为安卓平台开发服务。

在我们的服务中，我们需要每隔一分钟将设备的 GPS 数据(纬度和经度)发送到一些外部 REST 服务。

锁定设备后，它可以正常运行近 15 分钟。但在那之后它不发送任何数据。

解锁设备后，它再次开始通过 REST 服务发送数据。

到目前为止我的代码

public class MainActivity extends AppCompatActivity {

private PendingIntent pendingIntent;
private PowerManager.WakeLock wakeLock;

public static final String USER_NAME = "USERNAME";

String username;
String password;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    Intent alarm = new Intent(this, AlarmReceiver.class);
    boolean alarmRunning = (PendingIntent.getBroadcast(this, 0, alarm, PendingIntent.FLAG_NO_CREATE) != null);
    if(alarmRunning == false) {
        PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 0, alarm, 0);
        AlarmManager alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
        alarmManager.setRepeating(AlarmManager.ELAPSED_REALTIME_WAKEUP, SystemClock.elapsedRealtime(), 30000, pendingIntent);
    }

    PowerManager mgr = (PowerManager)this.getSystemService(Context.POWER_SERVICE);
    wakeLock = mgr.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK,"MyWakeLock");
    wakeLock.acquire();
 }

public class BackgroundService extends Service  {

private boolean isRunning;
private Context context;
private Thread backgroundThread;

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

@Override
public void onCreate() {
    this.context = this;
    this.isRunning = false;
    this.backgroundThread = new Thread(myTask);
}

private Runnable myTask = new Runnable() {
    public void run() {
        // Do something here
        login("admin","admin");
        stopSelf();
    }
};

@Override
public void onDestroy() {
    this.isRunning = false;
}

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    if(!this.isRunning) {
        this.isRunning = true;
        this.backgroundThread.start();
    }
    return START_STICKY;
}

private void login(final String strLatitude, final String strLongitude) {


    class LoginAsync extends AsyncTask<String, Void, String> {

        String charset = "UTF-8";
        HttpURLConnection conn;
        DataOutputStream wr;
        StringBuilder result = new StringBuilder();
        URL urlObj;
        JSONObject jObj = null;
        StringBuilder sbParams;
        String paramsString;

        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            // loadingDialog = ProgressDialog.show(MainActivity.this, "Please wait", "Loading...");
        }

        @Override
        protected String doInBackground(String... params) {
            String uname = params[0];
            String pass = params[1];

            sbParams = new StringBuilder();

            try {
                sbParams.append("name").append("=")
                        .append(URLEncoder.encode(uname, charset));
                sbParams.append("&");
                sbParams.append("password").append("=")
                        .append(URLEncoder.encode(pass, charset));
            } catch (UnsupportedEncodingException e) {
                e.printStackTrace();
            }

            try {

                String url="http://192.168.0.122:1234/YegoService.svc/AddVehicleMovement";
                URL object=new URL(url);

                HttpURLConnection con = (HttpURLConnection) object.openConnection();
                con.setDoOutput(true);
                con.setDoInput(true);
                con.setRequestProperty("Content-Type", "application/json");
                con.setRequestProperty("Accept", "application/json");
                con.setRequestMethod("POST");

                JSONObject parent = new JSONObject();

                parent.put("strValidatorID","111");
                parent.put("TXT_LAT", "28.25252525");

                parent.put("TXT_LONG", "77.7777777");
                parent.put("DAT_DATE", "");
                con.connect();

                OutputStreamWriter wr = new OutputStreamWriter(con.getOutputStream());
                wr.write(parent.toString());
                wr.flush();
                wr.close();

                InputStream input = con.getInputStream();
                BufferedReader reader = new BufferedReader(new InputStreamReader(input));
                String line;

                while ((line = reader.readLine()) != null) {
                    result.append(line);
                }

                con.disconnect();

            } catch (IOException e) {
                e.printStackTrace();
            }
            catch (Exception ex) {
                ex.printStackTrace();
            }

            return result.toString();
        }

        @Override
        protected void onPostExecute(String result){
            String s = result.trim();
        }
    }

    LoginAsync la = new LoginAsync();
    la.execute("admin", "admin");

}

}

public class AlarmReceiver extends BroadcastReceiver {
String strLatitude;
String strLongitude;

@Override
public void onReceive(Context context, Intent intent) {
    Intent background = new Intent(context, BackgroundService.class);
    context.startService(background);
}
}

要做什么？

最佳答案

一种方法是让您依赖 AlarmManager :一旦您订阅了 AlarmManager，系统本身就会按照您设置的时间间隔运行您的代码，即使您的应用程序未处于 Activity 状态。每次运行时，您都可以决定处理一些代码...因此您完全避免了保持服务 Activity 的需要。

您需要的是一个将处理 AlarmManager Intent 的 Alarm 类。

创建您的闹钟:

public class Alarm extends BroadcastReceiver 
{

    private static final String TAG = "Alarm";

    @Override
    public void onReceive(Context context, Intent intent) 
    {   
        PowerManager pm = (PowerManager) context.getSystemService(Context.POWER_SERVICE);
        PowerManager.WakeLock wl = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "");
        wl.acquire();

        /***************
        Here you can do your stuff...
        This will be triggered every second. 
        Send data from here, or better: call an IntentService
        that will take care of it.
        ****************/

        wl.release();
    }

    public void SetAlarm(Context context)
    {
        Intent i = new Intent(context, Alarm.class);

        boolean alarmUp = (PendingIntent.getBroadcast(context, 0, i, PendingIntent.FLAG_NO_CREATE) != null);

        if (alarmUp)
        {
            // The alarm is already running, do not set it twice
        }
        else
        {
            AlarmManager am = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
            PendingIntent pi = PendingIntent.getBroadcast(context, 0, i, 0);
            am.setRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis(), 1000, pi); // 1000 Millisec means it will trigger it every second... and RTC_WAKEUP means that it will wake up your device if needed.
        }
    }

    // later on, use this method if you want to manually cancel the AlarmManager :

    public void CancelAlarm(Context context)
    {
        Intent intent = new Intent(context, Alarm.class);
        PendingIntent sender = PendingIntent.getBroadcast(context, 0, intent, 0);
        AlarmManager alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
        alarmManager.cancel(sender);
    }
}

在你的 Manifest 中声明这个 Alarm BroadcastReceiver

<receiver 
    android:name=".utils.Alarm"
    android:process=":remote" >
</receiver>

然后从您想要在 Activity 中调用此 AlarmManager 的位置!

Alarm alarm = new Alarm();

@Override
protected void onCreate(Bundle savedInstanceState) 
{

    alarm.SetAlarm(this);

}

// or if elsewhere you need to stop the Alarm :
alarm.CancelAlarm(this);

这是主要思想。 现在你需要处理屏幕打开或关闭。 对于这 2 种解决方案:您可以注册设备屏幕状态 Intent 并管理 AlarmManager 开/关...或者您可以让 AlarmManager 始终运行但在发送数据之前检查设备是否开/关...

希望这会有所帮助!

关于android - 是否可以在锁定设备后继续在 android 平台上运行服务？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/36399123/