Java编译器抛出抽象方法而不是越过所有抽象方法

Question

所以我试图扩展一个employee抽象类。代码如下：

abstract class Employee
{
    String firstName;
    String lastName;
    
    Employee(String firstName,String lastName)
    {
        this.firstName = firstName;
        this.lastName = lastName;
    }
    
    public String getName()
    {
        String fullName = this.firstName + " " + this.lastName;
        return fullName;
    }
    
    //abstract method 
    public abstract int getFeedback();
}

class SalesEmployee extends Employee
{
    double revenue;
    
    SalesEmployee(String firstName,String lastName,double revenue)
    {
        super(firstName,lastName);
        this.revenue = revenue;
    }
    
    public int getFeedback(double revenue)
    {
        if(revenue>55)
        {
            return 7;
        }
        else if (revenue>50)
        {
            return 6;
        }
        else if (revenue>40)
        {
            return 5;
        }
        else if (revenue>30)
        {
            return 3;
        }
        else if (revenue>20)
        {
            return 2;
        }
        else
        {
            return 1;
        }
        
    }
}

class CoderEmployee extends Employee
{
    int projects;
    
    CoderEmployee(String firstName,String lastName,int projects)
    {
        super(firstName,lastName);
        this.projects = projects;
    }
    
    public int getFeedback(int projects)
    {
        if(projects>20)
        {
            return 5;
        }
        else if (projects>15)
        {
            return 4;
        }
        else if (projects>10)
        {
            return 3;
        }
        else if (projects>5)
        {
            return 2;
        }
        
        else
        {
            return 1;
        }
        
    }
}


public class Main{
    public static void main(String[] args)
    {
    }
}

现在，正如您所看到的，我已经在两个子类中遍历了抽象方法getFeedback。但我得到了这个错误：

/tmp/eIRGYxws7Y/CoderEmployee.java:25: error: SalesEmployee is not abstract and does not override abstract method getFeedback() in Employee
class SalesEmployee extends Employee
^
/tmp/eIRGYxws7Y/CoderEmployee.java:66: error: CoderEmployee is not abstract and does not override abstract method getFeedback() in Employee
class CoderEmployee extends Employee

那么问题是什么呢？为什么在两个子类中都编写了getFeedback方法，却引发了这个错误

Answer 1

抽象的getfeedback()方法没有参数，而您的实现有一个参数。因此，它不是重写的，而是重载的。您还必须将参数添加到抽象定义中。此外，您的实现中的参数类型是不一致的，您必须使它们相互匹配或可分配。

java prettyprint-override">// in Employee
public abstract int getFeedback(double revenue);

// In SalesEmployee
public int getFeedback(double revenue) {
    ...
}

// In CoderEmployee
public int getFeedback(double projects) {
    ...
}