标题翻译
Java: Calling a parent's method with child's member variable
问题
假设我有一个抽象的父类，其中有在一个方法中使用的成员变量。
public abstract class Person{public String jobTitle;public void printJob(){System.out.println(jobTitle);}}
如果现在我有两个子类：
public class Teacher extends Person{public String jobTitle = "Teacher";}public class Janitor extends Person{public String jobTitle = "Janitor";}
而且我想避免代码克隆，即在这两个类中实现相同的 printJob() 方法，我现在有一个问题，因为 printJob() 方法无法访问子类的成员变量。
是否有办法调用父类的方法，但让方法使用子类的成员变量？
英文翻译
Let's say I have an abstract parent class that has member variables which are used in a method.
public abstract class Person{public String jobTitle;public void printJob(){System.out.println(jobTitle);}}
If I now have two child classes
public class Teacher extends Person{public String jobTitle = "Teacher";}public class Janitor extends Person{public String jobTitle = "Janitor";}
and I want to avoid code cloning, i.e. implementing the same printJob()-method in both classes, I now have a problem, since the printJob()-method is unable to access member variables of the child classes.
Is there any way that i can call a parent classes' method but have the method use the child classes' member variables?
答案1
得分: 2
你可以像这样使用抽象方法：
public abstract class Person {public void printJob() {System.out.println(getJobTitle());}protected abstract String getJobTitle();public static void main(String[] args) {Person teacher = new Teacher();Person janitor = new Janitor();System.out.println(teacher.getJobTitle());System.out.println(janitor.getJobTitle());}}class Teacher extends Person {@Overrideprotected String getJobTitle() {return "Teacher";}}class Janitor extends Person {@Overrideprotected String getJobTitle() {return "Janitor";}}
在根据 op 的评论更新代码后...
public class Person {public static void main(String[] args) {System.out.println(new Teacher().job);System.out.println(new Janitor().job);}private static class Teacher extends Person {private String job = "Teacher";}private static class Janitor extends Person {private String job = "Janitor";}}
英文翻译
You can use abstract methods like this
public abstract class Person {public void printJob() {System.out.println(getJobTitle());}protected abstract String getJobTitle();public static void main(String[] args) {Person teacher = new Teacher();Person janitor = new Janitor();System.out.println(teacher.getJobTitle());System.out.println(janitor.getJobTitle());}}class Teacher extends Person {@Overrideprotected String getJobTitle() {return "Teacher";}}class Janitor extends Person {@Overrideprotected String getJobTitle() {return "Janitor";}}
Updated after op's comment for code cloning...
public class Person {public static void main(String[] args) {System.out.println(new Teacher().job);System.out.println(new Janitor().job);}private static class Teacher extends Person {private String job = "Teacher";}private static class Janitor extends Person {private String job = "Janitor";}}
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