生成纯数字随机数

package com.test.springboot.utils;

import java.util.Random;

public class Test {
    public static void main(String[] args) {
        StringBuilder buf = new StringBuilder();
        Random random = new Random();
        //开头不为0
        int firstNumber = random.nextInt(9) + 1;
        buf.append(firstNumber);
        //设置所需纯数字随机数长度
        int length = 10;
        for(int i = 0; i < length - 1; ++i) {
            buf.append(random.nextInt(10));
        }
        System.out.println( Long.valueOf(buf.toString()));
    }
}

执行示例：