如何用java技术实现幸运抽奖活动系统

import java.util.Scanner;
public class LuckyNumber {
/**
* 幸运抽奖
*/
public static
void main(String[] args) {
String answer
= "y"; // 标识是否继续
String
userName = ""; // 用户名
String
password = ""; // 密码
int cardNumber
= 0; // 卡号
boolean
isRegister = false; // 标识是否注册
boolean
isLogin = false; // 标识是否登录
int max =
9999;
int min =
1000;
Scanner input
= new Scanner(System.in);
do {
System.out.println("*****欢迎进入奖客富翁系统*****");
System.out.println("\t1.注册");
System.out.println("\t2.登录");
System.out.println("\t3.抽奖");
System.out.println("***************************");
System.out.print("请选择菜单：");
int choice =
input.nextInt();
switch
(choice) {
case 1:
System.out.println("[奖客富翁系统
> 注册]");
System.out.println("请填写个人注册信息：");
System.out.print("用户名：");
userName =
input.next();
System.out.print("密码：");
password =
input.next();
//
获取4位随机数作为卡号
cardNumber =
(int)(Math.random()*(max-min))+min;
System.out.println("\n注册成功，请记好您的会员卡号");
System.out.println("用户名\t密码\t会员卡号");
System.out.println(userName
+ "\t" + password + "\t" + cardNumber);
isRegister =
true; // 注册成功，标志位设置为true
break;
case 2:
System.out.println("[奖客富翁系统
> 登录]");
if
(isRegister) { // 判断是否注册
//
3次输入机会
for (int i
= 1; i <= 3; i++) {
System.out.print("请输入用户名：");
String
inputName = input.next();
System.out.print("请输入密码：");
String
inputPassword = input.next();
if
(userName.equals(inputName) && password.equals(inputPassword)) {
System.out.println("\n欢迎您："
+ userName);
isLogin =
true; // 登录成功，标志位设置为true
break;
} else if
(i < 3) {
System.out.println("用户名或密码错误，还有"
+ (3 - i) + "次机会！");
} else
{
System.out.println("您3次均输入错误！");
}
}
} else
{
System.out.println("请先注册，再登录！");
}
break;
case 3:
System.out.println("[奖客富翁系统
> 抽奖]");
if
(!isLogin) { // 判断是否登录
System.out.println("请先登录，再抽奖！");
} else
{
//生成5个4位随机数字，并保存在数组中
int[]
luckynums = new int[5];
for(int i
= 0; i < luckynums.length; i++){
luckynums[i] =
(int)(Math.random()*(max-min))+min;
}
System.out.print("请输入您的卡号：");
int
yourcard = input.nextInt();
int
i;
System.out.print("\n本日的幸运数字为：");
for (i = 0;
i < luckynums.length; i++) {
System.out.print(luckynums[i]
+ " ");\
}
for (i = 0;
i < luckynums.length; i++) {
if
(luckynums[i] == yourcard) {
System.out.println("\n恭喜！您是本日的幸运会员！");
break;
}
}

if (i ==
luckynums.length) {
System.out.println("\n抱歉！您不是本日的幸运会员！");
}
}
break;
default:
System.out.println("[您的输入有误！]");
break;
}
System.out.print("继续吗？（y/n）:");
answer =
input.next();
System.out.println("");
} while
("y".equals(answer));
if
("n".equals(answer)) {
System.out.println("系统退出，谢谢使用！");

}

}
}