JAVA Bank Account(은행계좌 관리)

package java_week2;
 
public class Account {
    String id, pw;
    int balance;
     
    public Account() {}
    public Account (String id, String pw, int balance){
        this.id = id;
        this.balance = balance;
        this.pw = pw;
    }
     
    public void changePw(String pw){
         
        this.pw = pw;
         
    }
     
    public int getBalance(){
        return balance;
    }
     
    public int Deposit(int value){
        balance = balance + value;
        return balance;
    }
     
    public int Withdraw(int value){
        if(balance>=value){
            balance = balance - value ;
        }else{
            System.out.println("잔액이 부족합니다");
        }
            return balance;
             
    }
}
 
===============================================================================
package java_week2;
 
import java.util.Scanner;
 
public class AccountService {
    static Account [] acclist = new Account[100];
    static Scanner sc = new Scanner(System.in);
     
     
    public boolean Account_Create(String id, String pw, int balance){
        for (int i = 0; i < acclist.length; i++) {
            if(acclist[i] == null){
                acclist[i] = new Account(id, pw, balance); 
                return true;
            }
        }
        return false;
    }
     
    public boolean Deposit(String id, int deposit){
        for (int i = 0; i < acclist.length; i++) 
        {
            if(acclist[i] != null && acclist[i].id.equals(id))
            {
                acclist[i].Deposit(deposit);
                System.out.println("==============================");
                System.out.println(acclist[i].id+"님의 현재 잔액은 "+acclist[i].getBalance()+"원 입니다.");
                System.out.println("==============================");
                return true;
            }
        }
        return false;
    }
     
    public boolean Withdraw(String id, String pw, int withdraw){
        for (int i = 0; i < acclist.length; i++) 
        {
            if(acclist[i] != null && acclist[i].id.equals(id) && acclist[i].pw.equals(pw))
            {
                System.out.println("==============================");
                System.out.println(acclist[i].id+"님의 현재 잔액은 "+acclist[i].Withdraw(withdraw)+"원 입니다.");
                System.out.println("==============================");
                return true;
            }
            else if(acclist[i] != null && acclist[i].id.equals(id) && !(acclist[i].pw.equals(pw)))
            {
                System.out.println("==============================");
                System.out.println(acclist[i].id+"님 비밀번호가 올바르지 않습니다.");
                System.out.println("==============================");
            }
        }
        return false;
    }
     
    public void showList(){
        for (int i = 0; i < acclist.length; i++) {
            if(acclist[i] != null){
            System.out.println(" 사용자 ID : "+acclist[i].id + "\t\t잔액 : "+acclist[i].getBalance()+"원");
            }
        }
    }
     
     
    public void changePw(String id, String pw){
        for (int i = 0; i < acclist.length; i++) 
        {
            if(acclist[i] != null && acclist[i].id.equals(id) && acclist[i].pw.equals(pw))
            {
                System.out.println("변경하실 비밀번호를 입력하세요");
                String newPw = sc.next();
                acclist[i].changePw(newPw);
                 
                System.out.println("==============================");
                System.out.println(acclist[i].id+"님 비밀번호가 "+newPw+" 로 변경되었습니다.");
                System.out.println("==============================");
            }
            else if(acclist[i] != null && acclist[i].id.equals(id) && !(acclist[i].pw.equals(pw)))
            {
                System.out.println("==============================");
                System.out.println(acclist[i].id+"님 비밀번호가 올바르지 않습니다.");
                System.out.println("==============================");
            }
        }
    }
     
     
     
    public static void main(String[] args){
            AccountService as = new AccountService();
             
         
        do {
            System.out.print("0:종료, 1:계좌 생성 , 2:입금 , 3:출금, 4.전체 계좌 list, 5.비번 변경 = ?"); 
            int choice = sc.nextInt();
            if (choice==0) break;
            if (choice==1) 
            {
                System.out.print("사용자 ID = ");
                String id = sc.next();
                System.out.print("사용자 PW = ");
                String pw = sc.next();  
                System.out.print("사용자 잔액 = ");
                int balance = sc.nextInt(); 
                as.Account_Create(id, pw, balance);
            }
            if (choice==2)
            {
                System.out.print("사용자 ID = ");
                String id = sc.next();
                System.out.print("입금 금액 = ");
                int deposit = sc.nextInt();
                as.Deposit(id, deposit);
            }
            if (choice==3)
            {
                System.out.print("사용자 ID = ");
                String id = sc.next();
                System.out.print("사용자 PW = ");
                String pw = sc.next();
                System.out.print("출금 금액 = ");
                int withdraw = sc.nextInt();
                as.Withdraw(id, pw, withdraw);
            }
            if (choice==4){
                as.showList();
            }
            if (choice==5){
                System.out.print("사용자 ID = ");
                String id = sc.next();
                System.out.print("사용자 PW = ");
                String pw = sc.next();
                 
                as.changePw(id, pw);
            }
         
             
        }while(true);
}
}