java - 不抽象且不重写抽象方法行为

Question

我有一个模拟狐狸和兔子的小模拟器...我正在尝试制作 fox 和 rabbit 类来实现 actor 类，但我收到此错误消息，我不知道出了什么问题..

错误信息:rabbit Is not abstract and does not override abstract method act (java.until.List) in Actor

兔子类

import java.util.List;
import java.util.Random;


public class Rabbit extends Animal implements Actor
{
    // Characteristics shared by all rabbits (static fields).

    // The age at which a rabbit can start to breed.
    private static final int BREEDING_AGE = 5;
    // The age to which a rabbit can live.
    private static final int MAX_AGE = 40;
    // The likelihood of a rabbit breeding.
    private static final double BREEDING_PROBABILITY = 0.15;
    // The maximum number of births.
    private static final int MAX_LITTER_SIZE = 4;

    /**
     * Create a new rabbit. A rabbit may be created with age
     * zero (a new born) or with a random age.
     * 
     * @param randomAge If true, the rabbit will have a random age.
     * @param field The field currently occupied.
     * @param location The location within the field.
     */
    public Rabbit(boolean randomAge, Field field, Location location)
    {
        super(field, location);
        if(randomAge) {
            setAge(rand.nextInt(MAX_AGE));
        }
    }

    /**
     * This is what the rabbit does most of the time - it runs 
     * around. Sometimes it will breed or die of old age.
     * @param newRabbits A list to add newly born rabbits to.
     */
    public void act(List<Actor> newActors)
    {
        incrementAge();
        if(isActive()) {
            giveBirth(newRabbits);            
            // Try to move into a free location.
            Location newLocation = getField().freeAdjacentLocation(getLocation());
            if(newLocation != null) {
                setLocation(newLocation);
            }
            else {
                // Overcrowding.
                setDead();
            }
        }
    }


    public Animal getNewAnimal(boolean status, Field field, Location loc)
    {
        return new Rabbit(status, field, loc);
    }

    /**
     * Return the maximal age of the rabbit.
     * @return The maximal age of the rabbit.
     */
    protected int getMaxAge()
    {
        return MAX_AGE;
    }

    /**
     * Return the breeding age of the rabbit.
     * @return The breeding age of the rabbit.
     */
    protected int getBreedingAge()
    {
        return BREEDING_AGE;
    }

    /**
     * Return the breeding probability of the rabbit.
     * @return The breeding probability of the rabbit.
     */

    protected double getBreedingProbability()
    {
        return BREEDING_PROBABILITY;
    }

    /**
     * Return the maximal litter size of the rabbit.
     * @return The maximal litter size of the rabbit.
     */

    protected int getMaxLitterSize()
    {
        return MAX_LITTER_SIZE;
    }

}

Actor 类

import java.util.List;
/**
 * Write a description of interface Actor here.
 * 
 * @author (your name) 
 * @version (a version number or a date)
 */
public interface Actor
{
    /**
     * performs actor's regular behaviour
     */
    void act(List<Actor> newActors);
    /**
     * is the actor still active
     */
    boolean isActive();
}

Answer 1

通过实现 Actor，您 promise 实现 void act(List<Actor> xxx)方法，但你没有。你确实实现了一个方法 void act(List<Animal> xx) ，但这是一种不同的方法(具有不同的签名)。

简单地说，您没有正确覆盖 act方法:

public void act(List<Animal> newRabbits) != void act(List<Actor> newActors);

签名必须对应。自 act在 Actor 中是抽象的(作为接口(interface))您必须在实现 Actor 的类中重写它或者声明它abstract (无法实例化它。