Gerar 4 cartelas LOTOFACIL

TextView textView1 = (TextView) findViewById(R.id.textview1);
TextView textView2 = (TextView) findViewById(R.id.textview2);
TextView textView3 = (TextView) findViewById(R.id.textview3);
TextView textView4 = (TextView) findViewById(R.id.textview4);

Set<Integer> randomNumbers1 = new HashSet<>();
while (randomNumbers1.size() < 15) {
    randomNumbers1.add(new Random().nextInt(26));
}

Set<Integer> randomNumbers2 = new HashSet<>();
while (randomNumbers2.size() < 15) {
    randomNumbers2.add(new Random().nextInt(26));
}

Set<Integer> randomNumbers3 = new HashSet<>();
while (randomNumbers3.size() < 15) {
    randomNumbers3.add(new Random().nextInt(26));
}

Set<Integer> randomNumbers4 = new HashSet<>();
while (randomNumbers4.size() < 15) {
    randomNumbers4.add(new Random().nextInt(26));
}

textView1.setText(TextUtils.join(", ", randomNumbers1));
textView2.setText(TextUtils.join(", ", randomNumbers2));
textView3.setText(TextUtils.join(", ", randomNumbers3));
textView4.setText(TextUtils.join(", ", randomNumbers4));