我正在通过抽象类AbstractAffiliate实现一个接口'Comparable',它由抽象类Abstract Faculty扩展,它由常规类Assistant扩展。
在助手类中实现compareTo方法(已在上面的所有类/接口中声明)后,编译器会给出此错误。
Assistant.java:1:错误:助手不是抽象的,并且不会覆盖抽象方法中的抽象方法compareTo()公共类助手扩展AbstractFaculty {^ 1错误
我已经尝试添加作为实现Comparable的泛化器。
public abstract class AbstractAffiliate implements Printable, Comparable<AbstractAffiliate>{
protected String name;
protected int age;
protected String address;
protected int phoneNumber;
protected int yearTheyCameToChapman;
/**
* Default empty AbstractAffiliate constructor
*/
public AbstractAffiliate() {
super();
age = 0;
address = " ";
phoneNumber = 0;
yearTheyCameToChapman = 0;
}
public AbstractAffiliate(String name, int age, String address, int phoneNumber, int yearTheyCameToChapman){
this.name = name;
this.age = age;
this.address = address;
this.phoneNumber = phoneNumber;
this.yearTheyCameToChapman = yearTheyCameToChapman;
}
public abstract String print();
public abstract int compareTo();
}
public abstract class AbstractFaculty extends AbstractAffiliate{
protected int facultyId;
protected String department;
protected int yearlySalary;
protected int numberOfPapers;
/**
* Default empty AbstractFaculty constructor
*/
public AbstractFaculty() {
super();
facultyId = 0;
department = " ";
yearlySalary = 0;
numberOfPapers = 0;
}
/**
* Default AbstractFaculty constructor
*/
public AbstractFaculty(String name, int age, String address, int phoneNumber, int yearTheyCameToChapman, int facultyId, String department, int yearlySalary, int numberOfPapers) {
super(name, age, address, phoneNumber, yearTheyCameToChapman);
this.facultyId = facultyId;
this.department = department;
this.yearlySalary = yearlySalary;
this.numberOfPapers = numberOfPapers;
}
public abstract String print();
public abstract int compareTo();
}
public class Assistant extends AbstractFaculty{
private int yearsUntilTenure;
public Assistant(){
super();
yearsUntilTenure = 0;
}
public Assistant(String name, int age, String address, int phoneNumber, int yearTheyCameToChapman, int facultyId, String department, int yearlySalary, int numberOfPapers, int yearsUntilTenure){
super(name, age, address, phoneNumber, yearTheyCameToChapman, facultyId, department, yearlySalary, numberOfPapers);
this.yearsUntilTenure = yearsUntilTenure;
}
public String print(){
return "yup";
}
public int compareTo(AbstractAffiliate affiliate){
if (this.yearTheyCameToChapman < affiliate.yearTheyCameToChapman){
return 1;
}
if (this.yearTheyCameToChapman > affiliate.yearTheyCameToChapman){
return -1;
}
else{
return 0;
}
}
}
```[enter image description here][1]
[1]: https://i.stack.imgur.com/Xdz2F.png
您尚未实现抽象方法。抽象的.compareTo()
方法不带参数。相比之下,您在Assistant
类中实现的版本将AbstractAffiliate
作为参数。由于它们具有不同的参数,因此它们使它们完全不同。
乍一看,看起来像参数的版本是你想要的那个,并且应该由你的基类实现Comparable<AbstractAffiliate>
的事实来处理,所以只需完全删除你的抽象compareTo()
方法,你应该没问题。
Comparable#compareTo的方法签名如下:
public int compareTo(T o);
但是在Assistant和它的父类中,你添加了一个抽象方法
public abstract int compareTo();
这与Comparable#compareTo
的方法不同。只需从其父类中删除public abstract int compareTo();
方法就可以解决问题,不需要一次又一次地声明它。
这是因为你声明要实现Comparable<AbstractAffiliate>
并且你没有实现该方法
int compareTo(AbstractAffiliate o)
你有一个不同的签名(没有参数)由于AbstractAffiliate
和AbstractFaculty
被声明为摘要,他们不必从Comparable
接口实现该方法。助理班需要。
请参阅Comparable