1定义宠物标准，用一个pet接口
package petshop;

public interface Pet {
public String getName();
public int getAge();
public float getPrice();
}

2定义宠物商店，其中可定义宠物个数，增加宠物数量，查询宠物
package petshop;

public class PetShop {
private Pet[] pets;//表示有多个宠物
private int foot;
public PetShop(int len){   //宠物个数可通过外部指定
if(len>0){
this.pets=new Pet[len];
}
else{
this.pets=new Pet[1];  //至少保留一个宠物
}
}
public Boolean addPet(Pet p){    //增加宠物
if(this.foot<pets.length){    //如果角标小于限定的宠物数量则可以增加宠物
this.pets[foot]=p;        //保存宠物
this.foot++;           //角标增加
return true;           //增加成功
}
else{
return false;      //增加失败
}
}
//查询时可能返回多个内容，还应该以数组的形式返回
public Pet[] search(String keyword){    //根据关键字查询
Pet[] result=null;   //声明数组，大小不确定
int count=0;      //记录有多少种宠物符合信息
for(int i=0;i<this.pets.length;i++){
if(this.pets[i]!=null){  //表示有宠物信息
if(this.pets[i].getName().indexOf(keyword)!=-1){  //查询到了结果
count++;
}
}
}
result=new Pet[count];   //根据查出的个数开辟数组空间
count=0; //加入内容
for(int i=0;i<this.pets.length;i++){
if(this.pets[i]!=null){  //表示有宠物信息
if(this.pets[i].getName().indexOf(keyword)!=-1){  //查询到了结果
result[count]=this.pets[i];    //返回查询的结果
count++;
}
}
}
return result;
}
}
3定义宠物猫，宠物狗
//宠物猫
package petshop;

public class Cat implements Pet {
public String name;
public int age;
public float price;

public Cat(String name, int age, float price) {
this.name = name;
this.age = age;
this.price = price;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public float getPrice() {
return price;
}
public void setPrice(float price) {
this.price = price;
}
public String toString() {

return "宠物猫的名字："+this.getName()+",年龄："+
this.getAge()+",价格："+this.getPrice();
}
}
//宠物狗
package petshop;

public class Dog implements Pet {
public String name;
public int age;
public float price;

public Dog(String name, int age, float price) {
this.name = name;
this.age = age;
this.price = price;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public float getPrice() {
return price;
}
public void setPrice(float price) {
this.price = price;
}
@Override
public String toString() {

return "宠物狗的名字："+this.getName()+",年龄："+
this.getAge()+",价格："+this.getPrice();
}
}
4建立测试类，测试类之间的关系
package petshop;

public class TestPetShop {

public static void main(String[] args) {
PetShop shop=new PetShop(5);  //定义能存放5个宠物的商店
shop.addPet(new Cat("黑猫",3,89.4f));   //增加宠物成功
shop.addPet(new Cat("白猫",2,34.4f));
shop.addPet(new Cat("花猫",4,76.4f));
shop.addPet(new Dog("白狗",1,123.5f));
shop.addPet(new Dog("黑狗",5,23.5f));
shop.addPet(new Dog("死狗",6,3.5f));   //增加失败
Pet[] p=shop.search("狗");
for(int i=0;i<p.length;i++){
System.out.println(p[i]);
}
}

}