actiity main2

package com.example.myapplication;
import android.widget.Button;
import androidx.appcompat.app.AppCompatActivity;

import java.util.Collections;

public class MainActivity extends AppCompatActivity {

    TextView textView;
    Button button;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        textView = (TextView) findViewById(R.id.textview);
        button = (button) findViewById(R.id.button);

        button.setOnClickListener((view) {
                ArrayList<Integer>list = new ArrayList<~>();
                for (int i = 1; i <=49; i++)
                {
                    list.add(i);
                }
        Collections.shuffle(list);
                ArrayList<Integer> chosen = new ArrayList<~>();
                for (int = 0; i < 6; i++)
                {
                    chosen.add(list.get(i));
                }
                Collections.sort(chosen);
                StringBuilder sb = new StringBuilder();
                for(int i: chosen)
                {
                    sb.append(String.valueOf(i));
                    sb.append(", ");
                }
                textView.setText(sb.toString().replaceAll(regex ", $", replacement ""));
        });
    }
}