matche用法

import java.util.Scanner;
import java.util.Scanner;

public class StringRegTest {
    public static void main(String[] args) {
        //1.定义描述规则的正则表达式字符串并使用变量记录
        //String Reg = "[0-9]{6}";
        //String Reg = "^[0-9]{6}$";
        String Reg = "\\d{6}";


        System.out.println("请输入您的银行卡密码!!!");
        while (true){
        Scanner sc =new Scanner(System.in);
        String str1= sc.next();

            if(str1.matches(Reg)){
                System.out.println("您输入的银行卡密码正确!!");
                break;
            }else {
                System.out.println("您输入的银行卡格式不正确!!");
            }
        }
    }
}