implem 不是抽象的，不会在扩展接口中覆盖抽象方法 FinalScore()

Question

节目 1

interface java{
    public void setHomeTeam(String name);
    public void setVisitingTeam(String name);
}

节目 2

interface extension extends java {
    public String HomeTeamScored();
    public String VisitingTeamScored();
    public String FinalScore();
}

节目 3

public class implem implements extension{
    private String Home;
    private String Visit;

    public String HomeTeamScored(){
        return Home;
    }

    public String VisitingTeamScored(){
        return Visit;
    }

    public void setHome(String Home){
        this.Home = Home;
    }

    public void setVisit(String Visit){
        this.Visit = Visit;
    }
}

节目 4

public class compilation{
    public static void main(String [] args){
        implem implement = new implem();

        implement.setHome("Nihon");
        implement.setVisit("Chuugoku");

        System.out.println(""+implement.HomeTeamScored());
        System.out.println(""+implement.VisitingTeamScored());
    }
}

这些是我用于扩展接口的程序，但出现错误：

implem is not abstract and does not override abstract method FinalScore() in extension public class implem implements extension{ ^ 1 error

Process completed.

Answer 1

因为你正在实现'extension'你需要实现你需要添加的接口中的所有方法

Public String FinalScore();

给你的class

Answer 2

您的非抽象 class implem 没有实现接口的所有方法。 Public String FinalScore()就是这样一种方法。

Answer 3

您可以找到 java 接口的定义[site]

它说

If your class claims to implement an interface, all methods defined by that interface must appear in its source code before the class will successfully compile

因此，您的实现 class 必须实现 java 及其子 class 扩展的所有接口方法。

你的实现 class 必须遵循规则，所以它看起来如下，

public class implem implements extension {
    private String Home;
    private String Visit;

    @Override
    public String HomeTeamScored() {
        return Home;
    }

    @Override
    public String VisitingTeamScored() {
        return Visit;
    }

    @Override
    public void setHomeTeam(String name) {

    }

    public void setHome(String Home) {
        this.Home = Home;
    }

    public void setVisit(String Visit) {
        this.Visit = Visit;
    }

    @Override
    public void setVisitingTeam(String name) {

    }

    @Override
    public String FinalScore() {

        return null;
    }
}

implem 不是抽象的，不会在扩展接口中覆盖抽象方法 FinalScore()

implem is not abstract and does not override abstract method FinalScore() in extending interfaces

java

interface

extend