JAVA:类型参数隐藏类类型

Question

我有这个

abstract class Operand {
    public abstract <T extends Operand> Operand operation(Operator operator, T operand);
}
abstract class Numeric extends Operand {
}
class Integer extends Numeric 
    @Override
    public <Integer> Operand operation(Operator operator, Integer operand) {//problem
    }
}

我该如何解决这种情况？ 我不想在类 Operand 中使用泛型(所以我有 Operand)，因为我需要 Operand 是单一类型。在 Integer 的方法内部，我需要调用构造函数(new Integer(arg))，解决方案可能是以其他方式调用该方法。 解决方案？

Answer 1

尝试使用重载方法

abstract class Operand {
    public abstract <T extends Operand> Operand operation(Operator operator, T operand);
}

abstract class Numeric<T extends Numeric<T>> extends Operand {
    public abstract Operand operation(Operator operator, T operand);
}

class Integer extends Numeric<Integer> {

    @Override
    public Operand operation(Operator operator, Integer operand) {
        // add your Integer specific code here
        return null; // replace null with actual returned value
    }

    @Override
    public <T extends Operand> Operand operation(Operator operator, T operand) {
        // simply call to overridden Integer specific method
        // no harm to downcast it here
        return operation(operator, (Integer) operand); 
    }

}