学习完异常处理后，我们可以将数据校验放在一起做。从此不必输入一个，校验一个。 这样的编程风格不好，容易打断业务流程的描述，特别是数据输入较多的时候。 请按照Main类及输出案例 1. 编写抽象类Pet，包含构造方法, 抽象方法eat和setNameAge及成员变量：name, age； 2. 编写Dog类（Pet类的子类）。 3. 编写AgeException异常类，当年龄不大于零，抛出该类异常（Dog类中的setNameAge方法中抛异常, 输出：AgeException: age cannot be this.age）。 import java.util.*; public class Main { public static void main(String[] args) { Scanner r = new Scanner(System.in); int count; try { count = r.nextInt(); Pet petList[] = new Pet[count]; for(int i=0;i<count;i++) { String name; int age; petList[i] = new Dog(); name = r.next(); age = r.nextInt(); petList[i].setNameAge(name, age); petList[i].eat(); } } catch(AgeException e) { System.out.println(e); } catch(InputMismatchException e) { System.out.println(e+ ": count or age must be an integer"); } catch(Exception e) { System.out.println(e+": other exception"); } } } 样例输入 4a aa 11 bb 22 cc 33 dd 44 样例输出 java.util.InputMismatchException: count or age must be an integer

以下是代码实现：

import java.util.*;

abstract class Pet {
    protected String name;
    protected int age;

    public Pet(String name, int age) {
        this.name = name;
        this.age = age;
    }

    public abstract void eat();

    public abstract void setNameAge(String name, int age);
}

class Dog extends Pet {
    public Dog() {
        super("", 0);
    }

    public void eat() {
        System.out.println(name + " is eating.");
    }

    public void setNameAge(String name, int age) {
        if (age <= 0) {
            throw new AgeException("AgeException: age cannot be " + age);
        }
        this.name = name;
        this.age = age;
    }
}

class AgeException extends RuntimeException {
    public AgeException(String message) {
        super(message);
    }
}

public class Main {
    public static void main(String[] args) {
        Scanner r = new Scanner(System.in);
        int count;
        try {
            count = r.nextInt();
            Pet petList[] = new Pet[count];
            for (int i = 0; i < count; i++) {
                String name;
                int age;
                petList[i] = new Dog();
                name = r.next();
                age = r.nextInt();
                petList[i].setNameAge(name, age);
                petList[i].eat();
            }
        } catch (AgeException e) {
            System.out.println(e);
        } catch (InputMismatchException e) {
            System.out.println(e + ": count or age must be an integer");
        } catch (Exception e) {
            System.out.println(e + ": other exception");
        }
    }
}

输入样例：

4a aa 11 bb 22 cc 33 dd 44

输出样例：

java.util.InputMismatchException: count or age must be an integer