java随机生成端口 java生成随机码

关键语句：生成随机码

Double random = Math.random();
String str = random.toString().substring(2, 11);//生成11-2位数字

附源代码：

package main;

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

public class Main {
    public Main() {
    }

    public static void main(String[] args) {
        Set<String> set = new HashSet();
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入要生成几个随机码");
        int n = sc.nextInt();

        for(int i = 0; i < n; ++i) {
            Double random = Math.random();
            String str = random.toString().substring(2, 11);
            set.add(str);
        }

        System.out.println("随机码：");
        Iterator it = set.iterator();

        while(it.hasNext()) {
            System.out.println((String)it.next());
        }

    }
}

生成结果展示

568576027	301283893
840040607	752140823
989588995	573906440
065227008	260841362
720058843	901780920