如何显示从GCM收到的地图上的坐标？

Question

我开发了一个应用程序，我从我的php服务器通过GCM接收纬度和经度，所以我想要的是，如果我的Map活动已经打开，在地图上显示这些坐标，否则生成通知。请指导我如何做到这一点。

这是我的GcmIntentService

import com.google.android.gms.gcm.GoogleCloudMessaging;

import android.app.IntentService;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.os.SystemClock;
import android.support.v4.app.NotificationCompat;
import android.util.Log;

public class GcmIntentService extends IntentService{
    Context context;
    public static final int NOTIFICATION_ID = 1;
    private NotificationManager mNotificationManager;
    NotificationCompat.Builder builder;
    public static final String TAG = "GCM Demo";

    public GcmIntentService() {
        super("GcmIntentService");
        // TODO Auto-generated constructor stub
    }



    @Override
        protected void onHandleIntent(Intent intent) {
            // TODO Auto-generated method stub
            Bundle extras = intent.getExtras();
            String msg = intent.getStringExtra("message");
            GoogleCloudMessaging gcm = GoogleCloudMessaging.getInstance(this);
            String messageType = gcm.getMessageType(intent);

             if (!extras.isEmpty()) {

                 if (GoogleCloudMessaging.
                            MESSAGE_TYPE_SEND_ERROR.equals(messageType)) {
                        sendNotification("Send error: " + extras.toString());
                    } else if (GoogleCloudMessaging.
                            MESSAGE_TYPE_DELETED.equals(messageType)) {
                        sendNotification("Deleted messages on server: " +
                                extras.toString());
                    // If it's a regular GCM message, do some work.
                    } else if (GoogleCloudMessaging.
                            MESSAGE_TYPE_MESSAGE.equals(messageType)) {
                        // This loop represents the service doing some work.
                        for (int i=0; i<5; i++) {
                            Log.i(TAG, "Working... " + (i+1)
                                    + "/5 @ " + SystemClock.elapsedRealtime());
                            try {
                                Thread.sleep(500);
                            } catch (InterruptedException e) {
                            }
                        }
                        Log.i(TAG, "Completed work @ " + SystemClock.elapsedRealtime());
                        // Post notification of received message.
                        //sendNotification("Received: " + extras.toString());
                        sendNotification(msg);
                        Log.i(TAG, "Received: " + extras.toString());
                    }
                }
             GcmBroadcastReceiver.completeWakefulIntent(intent);
        }
        private void sendNotification(String msg) {
            mNotificationManager = (NotificationManager)
                    this.getSystemService(Context.NOTIFICATION_SERVICE);

            Log.i(TAG, msg);

            Intent myintent = new Intent(this, Map.class);
            myintent.putExtra("message", msg);
            PendingIntent contentIntent = PendingIntent.getActivity(this, 0,
                    myintent, PendingIntent.FLAG_UPDATE_CURRENT);

            NotificationCompat.Builder mBuilder =
                    new NotificationCompat.Builder(this)
            .setSmallIcon(R.drawable.ic_stat_gcm)
            .setContentTitle("GCM Notification")
            .setStyle(new NotificationCompat.BigTextStyle()
            .bigText(msg))
            .setContentText(msg);

            mBuilder.setContentIntent(contentIntent);
            mNotificationManager.notify(NOTIFICATION_ID, mBuilder.build());
        }




}

这是我从GCM收到的消息中提取纬度和经度的方法

        Intent intent = getIntent();

        String message = intent.getExtras().getString("message");
        try {
            json = new JSONObject(message);
            String lat = json.getString("lati");
            String lon = json.getString("longi");

            if ( map != null ) {

                Double l1,l2;



                l1 = Double.parseDouble(lat);
                l2 = Double.parseDouble(lon);


                LatLng newLatLong = new LatLng(l1, l2);
                map.addMarker(new MarkerOptions().position(newLatLong)
                              .title("Hello"));

            }
            }

        } catch (JSONException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }