声明摘要或缺失正文

Question

为什么在实现多重继承时出现错误？

import java.util.*;

interface Bakery
{
    public void bake(String cake,String cream);
    public void serve();
}
interface FoodCourt
{ 
    int cost=50;
    public void items(String puffs, String drinks);
    public void buffet(int cost, String delivery);
}
class Stall implements
 Bakery,FoodCourt
{ 
    public void bake(String cake, String cream)
    {
        System.out.println("Baking A Cake");
    }
    public void serve()
    {
        System.out.println("Serving the items");
    }
    public void items(String puffs, String drinks);
    {
        System.out.println("This is Item List");
    }
    public void buffet(int cost, String delivery);
    {
        System.out.println("Buffet Starts");
    }
}
class Dcoder 
{
    public static void main(String[] args)
    {
        Stall b1=new Stall();
        b1.bake("BlackForest", "Chocolate");
        b1.serve();
        FoodCourt f1=new Stall();
        f1.items("EggPuff", "ThumsUp");
        f1.buffet(50,"COD");
    }
}`

输出：

source_file.java:25: error: missing method body, or declare abstract
    public void items(String puffs, String drinks);
                ^
source_file.java:29: error: missing method body, or declare abstract
    public void buffet(int cost, String delivery);
                ^
2 errors

Answer 1

这是 Robby 提到的正确代码。

去掉这两个方法签名后面的分号

import java.util.*;

interface Bakery
{
    public void bake(String cake,String cream);
    public void serve();
}
interface FoodCourt
{ 
    int cost=50;
    public void items(String puffs, String drinks);
    public void buffet(int cost, String delivery);
}
class Stall implements
 Bakery,FoodCourt
{ 
    public void bake(String cake, String cream)
    {
        System.out.println("Baking A Cake");
    }
    public void serve()
    {
        System.out.println("Serving the items");
    }
    public void items(String puffs, String drinks)
    {
        System.out.println("This is Item List");
    }
    public void buffet(int cost, String delivery)
    {
        System.out.println("Buffet Starts");
    }
}
public class Dcoder 
{
    public static void main(String[] args)
    {
        Stall b1=new Stall();
        b1.bake("BlackForest", "Chocolate");
        b1.serve();
        FoodCourt f1=new Stall();
        f1.items("EggPuff", "ThumsUp");
        f1.buffet(50,"COD");
    }
}

Answer 2

这是可执行代码

 public class Dcoder {
          public static void main(String[] args)
        {
            Stall b1=new Stall();
            b1.bake("BlackForest", "Chocolate");
            b1.serve();
            FoodCourt f1=new Stall();
            f1.items("EggPuff", "ThumsUp");
            f1.buffet(50,"COD");
        }
          interface Bakery
    {
        public void bake(String cake,String cream);
        public void serve();
    }
    interface FoodCourt
    { 
        int cost=50;
        public void items(String puffs, String drinks);
        public void buffet(int cost, String delivery);
    }
    public  static class Stall implements
     Bakery,FoodCourt
    { 
        public void bake(String cake, String cream)
        {
            System.out.println("Baking A Cake");
        }
        public void serve()
        {
            System.out.println("Serving the items");
        }
        public void items(String puffs, String drinks)
        {
            System.out.println("This is Item List");
        }
        public void buffet(int cost, String delivery)
        {
            System.out.println("Buffet Starts");
        }
    }
    }

输出：

Baking A Cake
Serving the items
This is Item List
Buffet Starts
BUILD SUCCESSFUL (total time: 0 seconds)

Answer 3

你需要从实现类中删除 ;

**public void items(String puffs, String drinks) {
    System.out.println("This is Item List");
}
public void buffet(int cost, String delivery)
{
    System.out.println("Buffet Starts");
}**