将一些数据传递给另一个活动返回为空字符串错误

Question

我正在构建一个总线跟踪Android应用程序。用户通过edittext输入日志和lat，并将坐标传递给下一个活动。但是，当我尝试获取传递的数据并将其转换为double时，我得到一个空字符串错误。

strack.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            currselectedBus=busListArray.getSelectedItem().toString();
            new tracklat().execute(currselectedBus);
            new tracklong().execute(currselectedBus);
            res.setText("Tracking...");
            Intent intent = new Intent(getApplicationContext(), 
MapsActivity.class);
            Bundle extras = new Bundle();
            extras.putString("bus", currselectedBus.toString());
            extras.putString("lat", vtxtValidation.getText().toString());
            extras.putString("log", vtxtValidation2.getText().toString());
            intent.putExtras(extras);
            startActivity(intent);
        }
    });

然后我的代码获取字符串

public void onMapReady(GoogleMap googleMap) {
    Intent intent = getIntent();
    Bundle extras = intent.getExtras();
    String name=extras.getString("bus");
    String lat = extras.getString("lat");
    String log = extras.getString("log");

    double lt = Double.parseDouble(lat);
    double lg = Double.parseDouble(log);
    mMap = googleMap;
    LatLng loc = new LatLng(lt, lg);
    mMap.addMarker(new MarkerOptions().position(loc).title(name));
    mMap.moveCamera(CameraUpdateFactory.newLatLng(loc));
}

然后我收到以下错误

      05-09 11:54:12.471 31709-31709/tosan.example.tosan.buslocation 
    E/AndroidRuntime: FATAL EXCEPTION: main

     Process: tosan.example.tosan.buslocation, PID: 31709

    java.lang.NumberFormatException: empty String

    at java.lang.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:1071)

    at java.lang.Double.parseDouble(Double.java:547)

    at 
   tosan.example.tosan.buslocation.MapsActivity.onMapReady(MapsActivity.java:50)

  at com.google.android.gms.maps.zzak.zza(Unknown Source)

  at com.google.android.gms.maps.internal.zzaq.dispatchTransaction(Unknown 
  Source)

  at com.google.android.gms.internal.maps.zzb.onTransact(Unknown Source)

  at android.os.Binder.transact(Binder.java:507)

  at fh.b(:com.google.android.gms.dynamite_dynamitemodulesb@12529021@12.5.29 (040400-192802242):20)

 at 

 com.google.android.gms.maps.internal.bg.a(:com.google.android.gms.dynamite_dyna 
 mitemodulesb@12529021@12.5.29 (040400-192802242):5)``

 at 
 com.google.maps.api.android.lib6.impl.be.run(:com.google.android.gms.dynamite_d 
ynamitemodulesb@12529021@12.5.29 (040400-192802242):5)

    at android.os.Handler.handleCallback(Handler.java:751)

    at android.os.Handler.dispatchMessage(Handler.java:95)

    at android.os.Looper.loop(Looper.java:154)

    at android.app.ActivityThread.main(ActivityThread.java:6682)

    at java.lang.reflect.Method.invoke(Native Method)

    at 

  com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1520)

    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1410)

    05-09 11:54:14.449 31709-31958/tosan.example.tosan.buslocation W/DynamiteModule: Local module descriptor class for com.google.android.gms.googlecertificates not found.



05-09 11:54:14.469 31709-31958/tosan.example.tosan.buslocation I/DynamiteModule: Considering local module com.google.android.gms.googlecertificates:0 and remote module com.google.android.gms.googlecertificates:4


05-09 11:54:14.470 31709-31958/tosan.example.tosan.buslocation I/DynamiteModule: Selected remote version of com.google.android.gms.googlecertificates, version >= 4
05-09 11:54:14.493 31709-31958/tosan.example.tosan.buslocation W/System: ClassLoader referenced unknown path: /data/user_de/0/com.google.android.gms/app_chimera/m/0000002b/n/arm64-v8a

05-09 11:54:15.663 31709-31930/tosan.example.tosan.buslocation I/System.out: (HTTPLog)-Static: isSBSettingEnabled false

05-09 11:54:15.666 31709-31930/tosan.example.tosan.buslocation I/System.out: (HTTPLog)-Static: isSBSettingEnabled false

05-09 11:54:16.546 31709-31718/tosan.example.tosan.buslocation I/art: Do partial code cache collection, code=18KB, data=30KB

05-09 11:54:16.548 31709-31718/tosan.example.tosan.buslocation I/art: After code cache collection, code=18KB, data=30KB

05-09 11:54:16.548 31709-31718/tosan.example.tosan.buslocation I/art: Increasing code cache capacity to 128KB