java基础_day0022_java_关键字_Override__子类_父类_个人账户存钱_消费_的测试

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原创最新推荐文章于 2026-05-03 09:47:29 发布 485 阅读 AI 写同款· GEO 优化 ›

Java自学习day12-继承和super练习-写一个名为 Account 的类模拟账户 1、写一个名为 Account 的类模拟账户。该类的属性和方法如下图所示。该类包括的属性：账号 id，余额 balance，年利率 annualInterestRate；包含的方法：访问器方法（getter 和 setter 方法），返回月利率的方法 getMonthlyInterest()，取款方法 withdraw()，存款方法 deposit()。写一个用户程序测试 Account 类。在用户程序中，创建一个账号为 1122、余额为 20000、年利率 4.5%的 Account 对象。使用阅读详情

账号类：

package day08_06;

public class Account {
	private int id;
	
	private double balance;
	
	private  double annualInterstRate;

	public int getId() {
		return id;
	}

	public void setId(int id) {
		this.id = id;
	}

	public double getBalance() {
		return balance;
	}

	public void setBalance(double balance) {
		this.balance = balance;
	}

	public double getAnnualInterstRate() {
		return annualInterstRate;
	}

	public void setAnnualInterstRate(double annualInterstRate) {
		this.annualInterstRate = annualInterstRate;
	}

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

//	当前月利率
	public  double  getMonthlyInterest(){
		return this.annualInterstRate/12;
	}
//	消费 
	public  void withdraw(double amount){
		if(this.balance>=amount){
			this.balance-=amount;
		}else{
			System.out.println("当前余额不足");
		}
	}
//	存钱
	public  void  deposit(double amount){
		this.balance+=amount;
	}
	
}

子类：重写父类方法 Override

package day08_06;

public class CheckAccount extends Account{
	
	private  double  overdraft;
	
	
	
	
	
	@Override
	public void withdraw(double amount) {
		
		if(amount<super.getBalance()){
			super.withdraw(amount);
		}else if(amount > super.getBalance()){
			if((amount-super.getBalance()) > overdraft ){
				System.out.println("超过可透支额度的限额！");
			}else{
				this.overdraft-=(amount-super.getBalance());
				super.setBalance(0);
			}
				
		}
	}
	
	





	public double getOverdraft() {
		return overdraft;
	}







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







	

}

测试父类的方法

package day08_06;

public class TestAccount {
	public static void main(String[] args) {
		Account acc = new  Account(1000,20000,0.045);
		acc.deposit(30000);
		acc.withdraw(2000);
		System.out.println(acc.getBalance());
	}
}

测试重写后子类的方法

package day08_06;

public class TestCheckAccount {
	public static void main(String[] args) {
		CheckAccount ca=new CheckAccount();
		ca.setBalance(20000);
		ca.setAnnualInterstRate(0.045);
		ca.setId(1122);
		ca.setOverdraft(5000);
		
		ca.withdraw(5000);
		System.out.println(ca.getBalance()+":-可透支额度"+ca.getOverdraft());
		ca.withdraw(18000);
		System.out.println(ca.getBalance()+":-可透支额度"+ca.getOverdraft());
		ca.withdraw(3000);
		System.out.println(ca.getBalance()+":-可透支额度"+ca.getOverdraft());
		
		
		
		
		
		
	}
}