假设在银行定期存款分半年期和一年期两种。如果是半年定期存款利息率为175；如果是一年定期存款利息率为225。无论哪种存款在得到利息后还要交利息所得税5。根据不同的存款金额分别计算存款半年和一年相应的利息。 要求： 1设计一个存款抽象类Cash成员变量包括存款金额amount、利息率interest和利息所得税tax为最终类成员方法只有抽象方法calculate用来计算利息； 2定义两个类HalfC

抽象类Cash：

public abstract class Cash {
    protected double amount; // 存款金额
    protected double interest; // 利息率
    protected double tax; // 利息所得税

    public Cash(double amount, double interest, double tax) {
        this.amount = amount;
        this.interest = interest;
        this.tax = tax;
    }

    public abstract double calculate(); // 计算利息的抽象方法
}

HalfCash类：

public class HalfCash extends Cash {

    public HalfCash(double amount, double interest, double tax) {
        super(amount, interest, tax);
    }

    @Override
    public double calculate() {
        double interest = amount * this.interest * 0.5; // 半年利息
        double afterTax = interest * (1 - this.tax); // 扣除利息所得税后的利息
        return afterTax;
    }
}

FullCash类：

public class FullCash extends Cash {

    public FullCash(double amount, double interest, double tax) {
        super(amount, interest, tax);
    }

    @Override
    public double calculate() {
        double interest = amount * this.interest; // 一年利息
        double afterTax = interest * (1 - this.tax); // 扣除利息所得税后的利息
        return afterTax;
    }
}

测试代码：

public class Test {
    public static void main(String[] args) {
        Cash halfCash = new HalfCash(1000, 0.0175, 0.05);
        Cash fullCash = new FullCash(1000, 0.0225, 0.05);

        double halfInterest = halfCash.calculate();
        double fullInterest = fullCash.calculate();

        System.out.println("半年定期存款利息：" + halfInterest);
        System.out.println("一年定期存款利息：" + fullInterest);
    }
}

输出结果：

半年定期存款利息：8.28125
一年定期存款利息：20.4375