Java Collection - 如何使用Set集合生成6个不同的随机数

import java.util.LinkedHashSet;
import java.util.Random;
import java.util.Set;

public class Main {

  public static void main(String[] args) {
    Set<Integer> intSet = new LinkedHashSet<Integer>();
    Random r = new Random();
    while (intSet.size() <= 6) {
      intSet.add(r.nextInt(49));
    }
    System.out.println(intSet);
  }
}