简单的ATM取款机项目开发。。

Account

public class Account {

  private String username;
	private String password;
	private double money;
	private boolean enable;
	
	public String getUsername() {
		return username;
	}
	public void setUsername(String username) {
		this.username = username;
	}
	public String getPassword() {
		return password;
	}
	public void setPassword(String password) {
		this.password = password;
	}
	public double getMoney() {
		return money;
	}
	public void setMoney(double money) {
		this.money = money;
	}
	public boolean isEnable() {
		return enable;
	}
	public void setEnable(boolean enable) {
		this.enable = enable;
	}

}

Atm

/**
 * ATM类
 * @author tom
 *
 */
public class Atm {

  private java.util.Scanner input = new java.util.Scanner(System.in);
	private Bank bank = new Bank();
	
	/**
	 * ATM启动方法
	 */
	public void start() {
		System.out.println("-----------------------");
		System.out.println("1. 开户");
		System.out.println("2. 插卡");
		System.out.println("3. 系统管理");
		System.out.println("4. 退出");
		System.out.println("-----------------------");
		
		System.out.println("请选择菜单项：");
		
		String index = input.next();
		
		if("1".equals(index)) {
			createAccount();
		} else if("2".equals(index)) {
			login();
		} else if("3".equals(index)) {
			adminLogin();
		} else if("4".equals(index)) {
			System.exit(0);
		} else {
			System.out.println("输入错误");
			start();
		}
	}
	
	/**
	 * 管理员登录
	 */
	private void adminLogin() {
		System.out.println("请输入管理员密码：");
		String password = input.next();
		
		if("000000".equals(password)) {
			showAdminMenu();
		} else {
			System.out.println("密码错误");
			start();
		}
		
	}

	/**
	 * 显示管理员登录后的菜单
	 */
	private void showAdminMenu() {
		System.out.println("------------------------------");
		System.out.println("1. 显示所有账户");
		System.out.println("2. 冻结账户");
		System.out.println("3. 恢复账户");
		System.out.println("4. 退出");
		System.out.println("------------------------------");
		
		System.out.println("请选择菜单项：");
		
		String index = input.next();
		
		if("1".equals(index)) {
			showAllAccount();
		} else if("2".equals(index)) {
			disableAccount();
		} else if("3".equals(index)) {
			enableAccount();
		} else if("4".equals(index)) {
			start();
		} else {
			System.out.println("输入错误");
			showAdminMenu();
		}
	}

	/**
	 * 恢复账户
	 */
	private void enableAccount() {
		Account[] accounts = bank.getAccounts();
		
		System.out.println("账户名\t\t\t是否可用");
		System.out.println("-----------------------------");
		for (int i = 0; i < accounts.length; i++) {
			if(accounts[i] != null && !accounts[i].isEnable()) {
				System.out.println(accounts[i].getUsername() + "\t\t\t" + (accounts[i].isEnable() ? "√" : "X"));
			}
		}
		
		System.out.println("请输入被恢复的账户名称：");
		String name = input.next();
		
		Account a = bank.validateByName(name);
		if(a == null) {
			System.out.println("该账户不存在");
		} else {
			a.setEnable(true);
			System.out.println("恢复成功");
		}
		showAdminMenu();
	}

	/**
	 * 冻结账号
	 */
	private void disableAccount() {
		Account[] accounts = bank.getAccounts();
		
		System.out.println("账户名\t\t\t是否可用");
		System.out.println("-----------------------------");
		for (int i = 0; i < accounts.length; i++) {
			if(accounts[i] != null && accounts[i].isEnable()) {
				System.out.println(accounts[i].getUsername() + "\t\t\t" + (accounts[i].isEnable() ? "√" : "X"));
			}
		}
		
		System.out.println("请输入被冻结的账户名称：");
		String name = input.next();
		
		Account a = bank.validateByName(name);
		if(a == null) {
			System.out.println("该账户不存在");
		} else {
			a.setEnable(false);
			System.out.println("冻结成功");
		}
		showAdminMenu();
	}

	/**
	 * 显示所有账户
	 */
	private void showAllAccount() {
		Account[] accounts = bank.getAccounts();
		
		System.out.println("账户名\t\t\t是否可用");
		System.out.println("-----------------------------");
		for (int i = 0; i < accounts.length; i++) {
			if(accounts[i] != null) {
				System.out.println(accounts[i].getUsername() + "\t\t\t" + (accounts[i].isEnable() ? "√" : "X"));
			}
		}
		showAdminMenu();
	}

	/**
	 * 账号登录
	 */
	private void login() {
		System.out.println("请输入账号：");
		String username = input.next();
		System.out.println("请输入密码：");
		String password = input.next();
		
		
		//根据用户名或密码来验证是否正确
		Account account = bank.validateByName(username);
		if(account != null && account.getPassword().equals(password)) {
			if(account.isEnable()) {
				System.out.println("欢迎你," + account.getUsername());
				showAccountMenu(account);
			} else {
				System.out.println("该账号被冻结，请联系所在银行");
			}
		} else {
			System.out.println("用户名或密码错误");
		}
		start();	
	}

	private void showAccountMenu(Account a) {
		System.out.println("---------------------------");
		System.out.println("1. 查询余额");
		System.out.println("2. 存款");
		System.out.println("3. 取款");
		System.out.println("4. 转账");
		System.out.println("5. 修改密码");
		System.out.println("6. 退出");
		System.out.println("---------------------------");
		System.out.println("请选择菜单项：");
		String index = input.next();
		
		if("1".equals(index)) {
			showAccountMoney(a);
		} else if("2".equals(index)) {
			saveMoney(a);
		} else if("3".equals(index)) {
			getMoney(a);
		} else if("4".equals(index)) {
			tranMoney(a);
		} else if("5".equals(index)) {
			editPassword(a);
		} else if("6".equals(index)) {
			start();
		} else {
			System.out.println("输入错误");
			showAccountMenu(a);
		}
		
	}

	private void tranMoney(Account a) {
		System.out.println("请输入转入方账号：");
		String inName = input.next();
		
		Account inAccount = bank.validateByName(inName);
		if(inAccount == null) {
			System.out.println("转入方账号错误");
		} else {
			if(inAccount.isEnable()) {
				
				boolean flag = false;
				do{
					System.out.println("请输入转账金额：");
					double money = input.nextDouble();
					
					if(money <= 0) {
						System.out.println("金额输入错误");
						flag = true;
					} else {
						if(a.getMoney() < money) {
							System.out.println("余额不足");
						} else {
							a.setMoney(a.getMoney() - money);
							inAccount.setMoney(inAccount.getMoney() + money);
							flag = false;
							System.out.println("转账成功");
						}
					}
				}while(flag);
			} else {
				System.out.println("转入方账号不可用");
			}
		}
		showAccountMenu(a);	
	}

	/**
	 * 修改密码
	 * @param a
	 */
	private void editPassword(Account a) {
		System.out.println("请输入原始密码：");
		String oldPassword = input.next();
		
		if(a.getPassword().equals(oldPassword)) {
			boolean flag = false;
			do{
				System.out.println("请输入新密码：");
				String password = input.next();
				
				System.out.println("请确认新密码：");
				String repassword = input.next();
				
				if(password.equals(repassword)) {
					a.setPassword(password);
					System.out.println("密码修改成功");
					flag = false;
				} else {
					System.out.println("两次密码不一致");
					flag = true;
				}
			}while(flag);
		} else {
			System.out.println("原始密码错误");
		}
		showAccountMenu(a);
	}

	/**
	 * 取款
	 * @param a
	 */
	private void getMoney(Account a) {
		System.out.println("请输入取款金额：");
		double money = input.nextDouble();
		
		if(money <= 0) {
			System.out.println("金额输入错误");
			saveMoney(a);
		} else {
			if(a.getMoney() < money) {
				System.out.println("余额不足");
			} else {
				a.setMoney(a.getMoney() - money);
				System.out.println("取款成功");
			}
			showAccountMenu(a);
		}
	}

	/**
	 * 存款
	 * @param a
	 */
	private void saveMoney(Account a) {
		System.out.println("请输入存款金额：");
		double money = input.nextDouble();
		
		if(money <= 0) {
			System.out.println("金额输入错误");
			saveMoney(a);
		} else {
			a.setMoney(a.getMoney() + money);
			System.out.println("存款成功");
			showAccountMenu(a);
		}
	}

	/**
	 * 显示账户余额
	 * @param a
	 */
	private void showAccountMoney(Account a) {
		System.out.println("余额：￥" + a.getMoney());
		showAccountMenu(a);
	}

	/**
	 * 开户
	 */
	private void createAccount() {
		System.out.println("请输入账号：");
		String name = input.next();
		
		//验证账号是否可用
		Account result = bank.validateByName(name);
		if(result == null) {
			//该账号可用
			boolean flag = false;
			do{
				System.out.println("请输入密码：");
				String password = input.next();
				
				System.out.println("请确认密码：");
				String repassword = input.next();
				
				if(password.equals(repassword)) {
					Account account = new Account();
					account.setUsername(name);
					account.setPassword(password);
					account.setEnable(true);
					
					boolean isSave = bank.save(account);
					
					if(isSave) {
						System.out.println("开户成功！");
					} else {
						System.out.println("服务器忙，请稍后...");
					}
					start();
					
				} else {
					System.out.println("两次密码不一致");
					flag = true;
				}
			}while(flag);
			
		} else {
			//该账号已被占用
			System.out.println("该账号已被占用");
			createAccount();
		}
	}

}

Bank

public class Bank {

  private Account[] accounts = new Account[100];
	
	public Account[] getAccounts() {
		return this.accounts;
	}
	
	/**
	 * 根据账号来验证该账号是否可用
	 * @param name 被验证的账号
	 * @return 如果可用返回true 否则false
	 */
	public Account validateByName(String name) {
		for (int i = 0; i < accounts.length; i++) {
			if(accounts[i] != null && accounts[i].getUsername().equals(name)) {
				return accounts[i];
			}
		}
		return null;
	}
	
	/**
	 * 将开户的account对象存入银行
	 * @param account
	 * @return
	 */
	public boolean save(Account account) {
		boolean flag = false;
		for (int i = 0; i < accounts.length; i++) {
			if(accounts[i] == null) {
				accounts[i] = account;
				flag = true;
				break;
			}
		}
		return flag;
	}
	
}

Test

public class Test {

  public static void main(String[] args) {
		
		Atm atm = new Atm();
		atm.start();
		
	}
}