123 lines
3.6 KiB
Java
123 lines
3.6 KiB
Java
package chapter2;
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import java.util.Scanner;
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public class User {
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// 存储用户名和密码
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// 两个数组前加上static属性，这样做是为了让本类都可以使用到这两个数组
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static String[] usernames = new String[10];
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static String[] passwords = new String[10];
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static int count = 1;
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public static void main(String[] args) {
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// 假设系统中已经有一个用户
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usernames[0] = "java";
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passwords[0] = "123456";
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while (true) {
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print();
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Scanner input = new Scanner(System.in);
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System.out.println("请选择功能：");
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int option = input.nextInt();
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switch (option) {
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case 0:
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System.exit(0);
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case 1:
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login();
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break;
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case 2:
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register();
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break;
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case 3:
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show();
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break;
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default:
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System.out.println("输入错误！");
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break;
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}
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}
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}
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/*
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* 登录功能，键盘输入用户名与密码
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* 使用for循环加if判断验证输入的用户名与密码是否正确
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*/
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public static void login() {
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Scanner input = new Scanner(System.in);
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System.out.println("请输入用户名：");
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String username = input.next();
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System.out.println("请输入密码：");
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String password = input.next();
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for (int i = 0; i < count; i++) {
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if (username.equals(usernames[i]) && password.equals(passwords[i])) {
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System.out.println("登录成功！");
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return;
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}
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}
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System.out.println("登录失败，请重新输入");
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}
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/*
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* 注册功能
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* 定义一个boolean变量，使用for循序判断用户是否存在
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* 如果用户不存在，在数组中插入注册的账号密码时
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* 可能会有数组长度不够的情况，所以需要使用到
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* 增加数组的长度，这里调用增加数组长度的方法add()。
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*/
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public static void register() {
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Scanner input = new Scanner(System.in);
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System.out.println("请输入用户名：");
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String username = input.next();
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System.out.println("请输入密码：");
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String password = input.next();
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boolean flag = true;
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for (int i = 0; i < count; i++) {
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if (username.equals(usernames[i])) {
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System.out.println("用户名已存在");
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flag = false;
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}
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}
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if (flag) {
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if (count < usernames.length) {
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count++;
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usernames[count - 1] = username;
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passwords[count - 1] = password;
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System.out.println("注册成功！");
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} else {
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System.out.println("数组空间不足！");
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}
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}
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}
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/*
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* 查看功能
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*/
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public static void show() {
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for (int i = 0; i < count; i++) {
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System.out.println("用户名：" + usernames[i] + "，密码：" + passwords[i]);
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}
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}
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/*
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* 打印功能菜单
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*/
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public static void print() {
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System.out.println("-----------------用户管理系统-------------------");
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System.out.println("1.登录功能");
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System.out.println("2.注册功能");
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System.out.println("3.查看");
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System.out.println("0.退出");
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System.out.println("-----------------用户管理系统-------------------");
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}
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}
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