n个不重复的随机数

import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;


public class ProduceRandom {
public static void main(String[] args) {
Set<String> set = new HashSet<String>();
int n = 10;//随机数个数
int length = 2;//随机数长度
for (int i = 0; i < n; i++) {
Double random = Math.random();
String str = random.toString().substring(2, length+2);
set.add(str);
}
System.out.println("随机数集合："+set);
//打印出随机数
Iterator<String> it = set.iterator();
while(it.hasNext()){
System.out.println(it.next());
}
}

}