java - 如何根据条件重写方法

Question

在我的预订类(class)中，我有这个方法来计算总金额

public void calcTotal(){
    total = amount*priceperbooking;

}

我创建了一个名为 BOOKING_APPLICATION 的子类，我想重写 calcTotal() 方法，如果 amount > 5 那么它必须减去总数的 15%

这是我尝试过的方法，但不起作用:

public void calcTotal(){
 if (super.amount>5) {
     super.total = super.total-(15/100.0*super.total);
 }

}

当我运行它时，它给出的是原始总数，而不是 15%我做错了什么

编辑:这是我的主类的代码

public class Diving_Adventures{
static BOOKING obj1 = new BOOKING();
static BOOKING_APPLICATION obj2 = new BOOKING_APPLICATION();


public static void main(String[] args) {

    obj1.setName();
    obj1.setNumber();
    obj1.setAmount();
    obj1.setPriceperbooking();
    obj1.calcTotal();
    obj2.calcTotal();



    JOptionPane.showMessageDialog(null, obj1.toString());
}


}

我假设通过 obj1.calcTotal() 它将计算总数，通过 obj2.calcTotal 它将取出 15%，但它不起作用

这是我的 BOOKING 类的完整代码:

private String name;
private int number;
public int amount;
public double priceperbooking;
public double total;





public String getName() {
    return name;
}

public int getNumber() {
    return number;
}

public int getAmount() {
    return amount;
}

public double getPriceperbooking() {
    return priceperbooking;
}

public void setName() {

    this.name =  JOptionPane.showInputDialog("Enter the name");;
}

public void setNumber() {

    this.number = Integer.parseInt(JOptionPane.showInputDialog("Enter the number"));
}

public void setAmount() {

    this.amount =  Integer.parseInt(JOptionPane.showInputDialog("Enter the amount"));
}

public void setPriceperbooking() {

    this.priceperbooking = Double.parseDouble(JOptionPane.showInputDialog("Enter the price per bookin"));;
}


public void calcTotal(){
    total = amount*priceperbooking;

}





@Override
public String toString() {
    return "Customer name: "+name+"\n"+"number"+ number + "\namount=" + amount + 
            "\n priceperbooking=" + priceperbooking + "\n total=" + total ;
}

Answer 1

在您的派生类中:

public void calcTotal() {
    total = super.calcTotal();
    if (amount > 5) {
       total = total - (15/100.0 * total); 
    }
}

如上所述，您没有首先计算总数。