java学习之第五章编程题示例（初学篇）

 /*
   Animal.java
 */
 package animal;

 public abstract class Animal {
  public    abstract void cry();
  public    abstract String getanimalName();
 }

 //Dog.java
 package animal;

 public class Dog extends Animal
 {

     String aa="旺旺";
     String dog_name ="旺财";
     @Override
     public void cry() {
         // TODO Auto-generated method stub
         System.out.println("小狗的叫声"+aa);
     }

     @Override
     public String getanimalName() {
         // TODO Auto-generated method stub
      return dog_name;
     }
 }

 //Cat.java
 package animal;

 public  class Cat extends Animal
 {
     String aa="喵喵";
     String bb="花花";
     @Override
     public void cry() {
         // TODO Auto-generated method stub
      System.out.println("小猫的叫声: "+aa);
     }

     @Override
     public String getanimalName() {
         // TODO Auto-generated method stub
         return bb;
     }
 }

 //Application.java
 package animal;

 public class Application {
     public static void main(String args[])
     {
       Simulator mysimulator =new Simulator();
       mysimulator.playSound(new Dog());
       mysimulator.playSound(new Cat());
     }
 }

 //Simulator.java
 package animal;

 public class Simulator {
     void playSound(Animal st)
     {
         System.out.println(st.getanimalName()+"的声音");
         st.cry();
     }
 }