java - 错误: compareTo(Object) in Car cannot implement compareTo(T) in Comparable

Question

public int compareTo(Object another) throws CustomMadeException
{
    if(this.getClass() != another.getClass() )
    {
        throw new CustomMadeException();
    }

    Car other = (Car) another;


    return this.getBrand().compareTo(other.getBrand());


}

我不明白我的代码到底出了什么问题。为什么它不能在Comparable中实现T？我是否必须将compareTo的参数更改为T？但不应该是Object吗？据我所知，compare接口(interface)中compareTo的实现是空白的。

Answer 1

执行此操作的规范方法如下:

public class Car implements Comparable<Car> {

    ...

    public int compareTo(Car other)
    {
        return this.getBrand().compareTo(other.getBrand());
    }
}

请注意，您的 compareTo() 的实现不能抛出任何检查异常，因为 Comparable<T>.compareTo() 不允许任何异常的throws规范。