代码如下
import java.util.Random;
public class MakeNum {
public static void main(String[] args) {
System.out.println(new MakeNum().makeNum());
}
//生成随机数
private String makeNum(){
//随机数生成对象new
Random random = new Random();
String num = random.nextInt(9999999) + "";
//构建一个16字符的字符串缓存区
StringBuffer sb = new StringBuffer();
//保险当随机数字不够7位时填充数字0补充到7位
for (int i = 0; i < 7 - num.length(); i++) {
sb.append("0"); //往sb里面加0
}
num = sb.toString() + num;
return num;
}
}
控制台打印: