如何从Java中的子类构造函数中删除参数

Question

在我的超类中，我定义了参数a、b、c和d。对于它的子类，我想删除d。有什么方法可以做到这一点吗？

abstract class Prescription {
protected Medicine Medicine;
protected Doctor doctor;
protected int patientID, thing;
public Resept(Medicine medicine, Doctor doctor, int patientID, int thing) {
this.legemiddel = legemiddel;
this.lege = utskrivendeLege;
this.pasientID = pasientID;
this.thing = thing;

在我的子类中，我想创建一个没有最后一个参数"的构造函数；事物；

public class TypeBPrescription extends Prescription {
public TypeBPresciption(Medicine medicine, Doctor doctor, int patientID){
super(Medicine medicine, Doctor doctor, int patientID,)
}
}

这样写会给我一个错误，即子类TypeBPrescription中的构造函数是未定义的。我希望子类不具有"；事物"；，但我想让我的超类拥有它。有办法做到这一点吗？

Answer 1

我会将一个默认值传递给超级类。

public TypeBPresciption(Medicine medicine, Doctor doctor, int patientID){
super(medicine, doctor, patientID, 0)
}

Answer 2

向super添加多个构造函数以澄清thing是可选的：

abstract class Prescription {
private static final int DEFAULT_THING = 0;
protected Medicine Medicine;
protected Doctor doctor;
protected int patientID, thing;
public Prescription (Medicine medicine, Doctor doctor, int patientID) 
{
this(medicine, doctor, paitentId, DEFAULT_THING);

public Prescription (Medicine medicine, Doctor doctor, int patientID, int thing) {
this.legemiddel = legemiddel;
this.lege = utskrivendeLege;
this.pasientID = pasientID;
this.thing = thing;
}

然后，子类可以使用任何适合其上下文的构造函数。