这怎么修改啊？

/*
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package c8;
import java.util.Scanner;

/**
 *
 * @author lenovo
 */
class Dog{
    public void eat(){
        System.out.println("Dog eating");
    }
    public void eats(){
        System.out.println("Dogs eating");
    }
}
class Cat{
    public void eat(){
        System.out.println("Cat eating");
    }
    public void eats(){
        System.out.println("Cats eating");
    }
}
class Feeder{
    public void Feed(String animal="Dog"){
        int i;
        if(animal.equals("Dog")){
            i=1;
        }else if(animal.equals("Dogs")){
            i=2;
        }else if(animal.equals("Cat")){
            i=3;
        }else if(animal.equals("Cats")){
            i=4;
        }
        switch(i){
            case 1:
                Dog dog=new Dog();
                dog.eat();
                break;
            case 2:
                Dog dogs=new Dog();
                dogs.eats();
                break;
            case 3:
                Cat cat=new Cat();
                cat.eat();
                break;
            case 4:
                Cat cats=new Cat();
                cats.eats();
                break;
            default:
                System.out.println("please input Dog(s) or Cat(s):");
                Feeder feed=new Feeder();
                feed.Feed();
        }
    }
}
        
        
        
        
public class Feeding {
    public static void main(String[] args){
        Feeder feed=new Feeder();
        Scanner can=new Scanner();
        String an=can.next();
        feed.Feed(an);
    }
}