package exer2;

public class Account {
	private int id;//账号
	private double balance;//余额
	private double annualInterestRate;//构造器

	public Account(int id,double balance,double annualInterstRate) {
		this.id = id;
		this.balance = balance;
		this.annualInterestRate = annualInterstRate;
	}
	public void setId(int id) {
		this.id = id;
	}
	public int getId() {
		return id;
	}
	public double getBalance() {
		return balance;
	}
	public void setBalance(double balance) {
		this.balance = balance;
	}
	public double getAnnualInterestRate() {
		return annualInterestRate;
	}
	public void setAnnualInterestRate(double annualInterestRate) {
		this.annualInterestRate = annualInterestRate;
	}

	public double getMonthlyInsert() {
		return annualInterestRate/12;
	}
	public void withdraw(double amount) {  //取款
		if(balance >= amount) {
			balance -= amount;
			return;
		}
		System.out.println("余额不足");
	}
	public void deposit(double amount) {   //存款
		if(amount > 0) {
			balance += amount;
		}
	}

}

package exer2;

public class AccountTest {
	public static void main(String[] args) {
		Account a = new Account(1122,20000,0.045);
		a.withdraw(30000);
		System.out.println("您的账户余额为："+a.getBalance());

		a.withdraw(2500);
		System.out.println("您的账户余额为："+a.getBalance());
		a.deposit(3000);
		System.out.println("您的账户余额为："+a.getBalance());

		System.out.println("月利率为："+(a.getMonthlyInsert()*100)+"%");

	}
}

package exer2;

public class CheckAccount extends Account {
	private double overdraft; // 可透支限额

	public CheckAccount(int id, double balance, double annualInterstRate, double overdraft) {
		super(id, balance, annualInterstRate);
		this.overdraft = overdraft;
	}

	@Override
	public void withdraw(double amount) {
		if(getBalance() >= amount) {  //余额足够消费
			//方法一
			//			setBalance(getBalance() - amount);
			//方法二
			super.withdraw(amount);
		}else if(overdraft >= (amount - getBalance())){   //透支额度 + 余额足够消费
			overdraft -= (amount - getBalance());
			//			 setBalance(0);
			//或
			super.withdraw(getBalance());
		}
		else {
			System.out.println("超过可透支限额！");
		}
	}

	public double getOverdraft() {
		return overdraft;
	}

	public void setOverdraft(double overdraft) {
		this.overdraft = overdraft;
	}

}

 

package exer2;

public class CheckAccountTest {
	public static void main(String[] args) {
		CheckAccount acct = new CheckAccount(1122, 20000, 0.045, 5000);
		acct.withdraw(5000);
		System.out.println("您的账户余额为："+acct.getBalance());
		System.out.println("您的可透支额度为："+acct.getOverdraft());
		acct.withdraw(18000);
		System.out.println("您的账户余额为："+acct.getBalance());
		System.out.println("您的可透支额度为："+acct.getOverdraft());
		acct.withdraw(3000);
		System.out.println("您的账户余额为："+acct.getBalance());
		System.out.println("您的可透支额度为："+acct.getOverdraft());
	} 
}