区域是记录的最佳方法吗？

Question

我正在尝试尽可能清晰地记录我的Java。我有少量的代码，不想过多解释。我目前正在使用区域，但不确定这是最好的方法。有哪些替代方案可以做区域事务，还是做得很好？

Java：

import android.annotation.SuppressLint;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.TextView;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import java.util.concurrent.TimeUnit;
import io.reactivex.Observable;
import io.reactivex.android.schedulers.AndroidSchedulers;


public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
}
//region Void is used to display amount of numbers without repeating a 
//number, time the number display, and clear the screen after every loop.
@SuppressLint("CheckResult")
public void display_numbers(View view) {
    final List<Integer> randomNumbers = new ArrayList<>();
    Observable.intervalRange(0, 6, 0, 472, TimeUnit.MILLISECONDS)
            .map(aLong -> {
                int previous = randomNumbers.size() > 0 ? randomNumbers.get(
                        randomNumbers.size() - 1) : -1;
                int randomNumber = generateRandomNumber();
                while (randomNumber == previous) randomNumber = 
generateRandomNumber();
                randomNumbers.add(randomNumber);
                return randomNumber;
            })
            .observeOn(AndroidSchedulers.mainThread())
            .subscribe(integer -> {
                TextView tv = (TextView) findViewById(R.id.textView1);
                tv.setText(String.valueOf(integer));
            }, error -> {}, () -> {
                TextView tv = (TextView) findViewById(R.id.textView1);
                tv.setText("");
            });
}
//endregion

//region Int used to randomize the numbers generated.
private int generateRandomNumber() {
        Random r = new Random();
        int minNumber = 1;
        int maxNumber = 9;
        return r.nextInt((maxNumber - minNumber) + 1) + minNumber;
}
//endregion
    }