猫狗队列

给定下面的宠物类，要求实现下面的要求：

    public  class Pet{
        private String type;
        public Pet(String type){
            this.type = type;
        }
        public String getPetType(){
            return this.type;
        }
    }

    public class Dog extends Pet{
        public Dog(){
            super("dog");
        }
    }

    public class Cat extends Pet{
        public Cat(){
            super("cat");
        }
    }

import java.util.LinkedList;
import java.util.Queue;

public class DogAndCatQueue {

    //原始的pet类
    public static class Pet{

        private String type;

        public Pet(String type){
            this.type = type;
        }

        public String getPetType(){
            return this.type;
        }
    }

    //原始的dog类
    public static class Dog extends Pet{

        public Dog(){
            super("dog");
        }

    }

    //原始的cat类
    public static class Cat extends Pet{

        public Cat(){
            super("cat");
        }

    }

    //新建一个宠物类
    public static class SuperPet{

        //装一个宠物和一个计数表示进队时间
        private Pet pet;
        private long count;

        public SuperPet(Pet pet,long count){
            this.pet = pet;
            this.count = count;
        }

        public Pet getPet(){
            return this.pet;
        }

        public long getCount(){
            return this.count;
        }

        public String getPetType(){
            return this.pet.getPetType();
        }

    }

    //猫狗队列
    public static class DogCatQueue{

        //创建两个队列表示猫队列和狗队列
        private Queue<SuperPet> dogQueue;
        private Queue<SuperPet> catQueue;
        private long count;

        public DogCatQueue(){
            this.dogQueue = new LinkedList<SuperPet>();
            this.catQueue = new LinkedList<SuperPet>();
            this.count = 0;
        }

        //猫狗进队列
        public void add(Pet pet){
            if(pet.getPetType().equals("dog")){
                this.dogQueue.add(new SuperPet(pet,this.count++));
            } else if(pet.getPetType().equals("cat")){
                this.catQueue.add(new SuperPet(pet,this.count++));
            } else {
                throw new RuntimeException("error,not dog or cat");
            }
        }

        //获得所有宠物里边的最早的宠物
        public Pet pollAll(){
            if(!this.dogQueue.isEmpty() && !this.catQueue.isEmpty()){
                if(this.dogQueue.peek().getCount() < this.catQueue.peek().getCount()){
                    return this.dogQueue.poll().getPet();
                } else {
                    return this.catQueue.poll().getPet();
                }
            } else if(!this.dogQueue.isEmpty()){
                return this.dogQueue.poll().getPet();
            } else if(!this.catQueue.isEmpty()){
                return this.catQueue.poll().getPet();
            } else {
                throw new RuntimeException("error,queue is empty");
            }
        }

        //取得最早的猫
        public Cat pollCat(){
            if(!this.catQueue.isEmpty()){
                return (Cat) this.catQueue.poll().getPet();
            } else {
                throw new RuntimeException("cat queue is empty");
            }
        }

        //取得最早的狗
        public Dog pollDog(){
            if(!this.dogQueue.isEmpty()){
                return (Dog) this.dogQueue.poll().getPet();
            } else {
                throw new RuntimeException("dog queue is empty");
            }
        }

        //判断队列是否为空
        public boolean isEmpte(){
            return this.dogQueue.isEmpty() && this.catQueue.isEmpty();
        }

        //判断队列中是否有狗
        public boolean dogIsEmpty(){
            return this.dogQueue.isEmpty();
        }

        //判断队列中是否有猫
        public boolean catIsEmpty(){
            return this.catQueue.isEmpty();
        }

    }

}