How i can compare the value of an id with java

I have a simple xml with a question and two buttons. When one of buttons is pushed i will compare if the id of the pushed button is equal to "Blanco" or "Negro". The XML code:

<LinearLayout xmlns:android="http://ift.tt/nIICcg"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <TextView
        android:id="@+id/textView1"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:text="@string/pregunta" />

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal" >

        <Button
            android:id="@+id/button1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/Blanco" 
            android:onClick="respuesta"/>

        <Button
            android:id="@+id/button2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/Negro" 
            android:onClick="respuesta"/>

    </LinearLayout>

</LinearLayout>

This is de java code:

public class MainActivity extends ActionBarActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    public void respuesta(){
        //The doubt.
        //Here the if/else to compare ID with the button text
    }
}