如何解决错误：Java类无法在android中的XML布局中实例化？

public class BottomToolbar extends RelativeLayout {
private Spinner circleSpinner;
private ImageButton operatorImageButton;
private ToggleButton conntypeToggleButton;
private Context context;

public BottomToolbar(Context context, AttributeSet attrs) {
    super(context, attrs);
    LayoutInflater layoutInflater = (LayoutInflater) context
            .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    View view = layoutInflater.inflate(R.layout.toolbar, this);
    this.context = context;
    circleSpinner = (Spinner) findViewById(R.id.spinner1);
    ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(
            context, R.array.circlesarray,
            android.R.layout.simple_spinner_item);
    adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    circleSpinner.setAdapter(adapter);
}}
public class BottomToolbar extends RelativeLayo