更新Firebase数据库中的现有数据

Question

我需要更新Firebase中的现有数据。编译代码时没有错误，但是不幸的是，当我按下Update按钮时应用程序停止了。在我的数据库中有两个子节点snakes和Habitat。用来存储数据。Logcat显示覆盖onclick方法时，String name=SciName.getSelectedItem().toString();处的Null指针异常。

 public void showUpdatedDialog(final String snakeID, String snakeName)  // dialog box
{
    AlertDialog.Builder dialogBuilder=new AlertDialog.Builder(this);
    LayoutInflater  inflater=getLayoutInflater();
    final View dialogView=inflater.inflate(R.layout.update_dialog,null);
    dialogBuilder.setView(dialogView);

    final Button updatebutton=(Button)dialogView.findViewById(R.id.btn_upload_snake);
    final Spinner SciName=(Spinner)findViewById(R.id.scientificName);
    final EditText Snakename=(EditText)findViewById(R.id.etSnakeName);
    final EditText Habitat1=(EditText)findViewById(R.id.etHabitat1);
    final EditText Habitat2=(EditText)findViewById(R.id.etHabitat2);
    final EditText Tretment=(EditText)findViewById(R.id.etTreatment);
    final EditText  Behaviour=(EditText)findViewById(R.id.etBehaviour);
    final EditText Venomousness=(EditText)findViewById(R.id.etVenomousness);
    final EditText Distribution=(EditText)findViewById(R.id.etDistribution);
    final EditText Habit=(EditText)findViewById(R.id.etHabit);
    final EditText Reproduction=(EditText)findViewById(R.id.etReproduction);


    dialogBuilder.setTitle("Updating Snake details::"+snakeName);

    final AlertDialog alertDialog=dialogBuilder.show();
    alertDialog.show();




    updatebutton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            String name=SciName.getSelectedItem().toString();
            String Sname=Snakename.getText().toString().trim();
            String H1=Habitat1.getText().toString().trim();
            String H2=Habitat2.getText().toString().trim();
            String Treatment=Tretment.getText().toString().trim();
            String Habit1=Habit.getText().toString().trim();
            String Behaviour2=Behaviour.getText().toString().trim();
            String Distribution2=Distribution.getText().toString().trim();
            String Reproduction2=Reproduction.getText().toString().trim();
            String Venom=Venomousness.getText().toString().trim();

            if(TextUtils.isEmpty(Sname)){
                Snakename.setError("Name Is Required");
                return;
            }
            updatesnake(snakeID,name,Sname,Treatment,Behaviour2,Venom,Distribution2,Habit1,Reproduction2,H1,H2);
            alertDialog.dismiss();
        }
    });


}


public  void updatesnake( String id, String SCINAME,String snakename, String TREATMENT,String BEHAVIOUR,String VENOMOUSNESS,String DISTRIBUTION,String HABIT,String REPRODUCTION,String HABITAT1,String HABITAT2){ // update details to snakes.
     DatabaseReference databaseSnake=FirebaseDatabase.getInstance().getReference("snake").child("id");
     Snake snake=new Snake(id ,SCINAME,snakename,TREATMENT,BEHAVIOUR,VENOMOUSNESS,DISTRIBUTION,HABIT,REPRODUCTION);
     databaseSnake.setValue(snake);

     DatabaseReference databaseSnake2=FirebaseDatabase.getInstance().getReference("habitat");
     Habitat habitat=new Habitat(HABITAT1,HABITAT2);
     databaseSnake2.child(id).setValue(habitat);

    Toast.makeText(this,"UPDATE IS SUCCESSFUL",Toast.LENGTH_LONG).show();

}

}