myRef.setValue("This is root node value").addOnCompleteListener(new OnCompleteListener<Void>() { @Override public void onComplete(@NonNull Task<Void> task) { if(task.isSuccessful()){ //Task was successful, data written! Toast.makeText(MainActivity.this, "Data saved!", Toast.LENGTH_SHORT).show(); }else{ //Task was not successful, Toast.makeText(MainActivity.this, "Something went wrong", Toast.LENGTH_SHORT).show(); //Log the error message Log.e(TAG, "onComplete: ERROR: " + task.getException().getLocalizedMessage() ); } } });