If you need to generate Random numbers in your Android app (assuming you���re using Java), you can simply use the java.util.Random class.

Random random = new Random(); // (1)
mrandomnumber = random.nextInt(100); // (2)

(1) Creates a new Random object

(2) Creates a new random integers not greater than 100

import android.util.Log;
import java.util.Random;

public class RandomNumber {

private String TAG = getClass().getSimpleName();

int mrandomnumber;
boolean minitialized = false;

String getNumber() {
if(!minitialized) {
createRandomNumber();
}
Log.i(TAG, "RETURN Random number");
return mrandomnumber + "";
}

void createRandomNumber() {
Log.i(TAG, "CREATE NEW Random number");
Random random = new Random();
mrandomnumber = random.nextInt(100);
minitialized = true;
}
}

Then, you can use it like this from MainActivity

public class MainActivity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

RandomNumber data = new RandomNumber();

((TextView) findViewById(R.id.txtrandom)).setText(data.getNumber());
}
}