public class MainActivity extends AppCompatActivity {
    final Context context = this; // 입력 부분
    @Override
    protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        dialog(); // 입력 부분
    }

    // 여기부터 입력
    public void dialog() {
      AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(context);
        alertDialogBuilder.setTitle(“프로그램 종료”);
        alertDialogBuilder
            .setMessage(“프로그램을 종료하겠습니까?”)
            .setCancelable(false)
            .setPositiveButton(“종료”, new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int id) {
                    MainActivity.this.finish();
                }
            })
            .setNegativeButton(“취소”, new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int id) {
                       dialog.cancel();
                    }
                });

        AlertDialog alertDialog = alertDialogBuilder.create();
        alertDialog.show();
    } // 여기까지 입력
}