End an activity

import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class LandingActivity extends Activity {

    public Button mRelaunchButton;

    // Some previous code omitted for brevity

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_landing);

        // Some previous code omitted for brevity

        mRelaunchButton = (Button)findViewById(R.id.relaunchButton);
        mRelaunchButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                super.onRelaunch();// Add your code here!

            }
        });
    }
}