Activityのfinish()メソッドの上書き

package cn.testfinish;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
/**
 * Demo :
 *  Activity finish() 
 *  finish() , onDestroy()
 *  Activity finish() , finish()
 *  finish() onDestroy() .
 */
public class MainActivity extends Activity {
    private Button mButton;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		init();
	}
    private void init(){
    	mButton=(Button) findViewById(R.id.button);
    	mButton.setOnClickListener(new OnClickListener() {
			@Override
			public void onClick(View view) {
				MainActivity.this.finish();
			}
		});
    }
    
    @Override
    public void finish() {
    	super.finish();
    	System.out.println(" finish() ");
    	
    }
    @Override
    protected void onDestroy() {
    	super.onDestroy();
    	System.out.println(" Activity onDestroy() ");
    }
	

}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
   >

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="click here"
        android:layout_centerInParent="true" 
    />

</RelativeLayout>