Java 使用ArrayList集合实现注册登陆功能

动手写了才对知识点有更深的感觉

再次体会到了Java是完全面向对象的语言，调动对象做事情

对迭代器的使用有了初步的认识

要遍历ArrayList集合的话有2种方法

1.使用toarray功能转为数组，再进行遍历

2.创建一个集合的迭代器,使用迭代器去遍历集合

package 第15天;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.Scanner;

public class test1 {

    public static class User{
        int id;
        String password;
        public User(int id, String password) {
            this.id = id;
            this.password = password;
        }
        public int getId() {
            return id;
        }
        public void setId(int id) {
            this.id = id;
        }
        public String getPassword() {
            return password;
        }
        public void setPassword(String password) {
            this.password = password;
        }

        @Override
        public boolean equals(Object obj) {
            User user =  (User) obj;
            return this.id == user.id;
        }

        @Override
        public String toString() {
            // TODO Auto-generated method stub
            return "账号：" + this.id + "密码：" + this.password;
        }
    }

    static Scanner scanner = new Scanner(System.in);
    static ArrayList users = new ArrayList();


    public static void login(){
        System.out.println("请输入账号");
        int id = scanner.nextInt();
        System.out.println("请输入密码");
        String password = scanner.next();
        boolean isLogin = false;
        Iterator it = users.iterator();
        while(it.hasNext()){
            User user = (User) it.next();
            if(user.id == id && user.password.equals(password)){
                isLogin = true;
                System.out.println("登录成功！");
            }else{
                System.out.println("登录失败！");
            }
        }
    }

    public static void reg(){
        User user = null;
        while(true){
            System.out.println("请输入账号");
            int id = scanner.nextInt();
            user = new User(id,null);
            if(users.contains(user)){
                System.out.println("已存在该账号！");
            }else{
                break;
            }
        }
        System.out.println("请输入密码");
        String password = scanner.next();
        user.setPassword(password);
        users.add(user);
        System.out.println("注册成功@");
        System.out.println("当前注册的人员" + users);
    }

    public static void main(String[] args) {
        while(true){
            System.out.println("请选择功能 A（注册） B（登录）");
            String option = scanner.next();
            if("a".equalsIgnoreCase(option)){
                reg();
            }else if("b".equalsIgnoreCase(option)){
                login();
            }else{
                System.out.println("输入有误，请重新输入");
            }
        }
    }

}