JavaSE-13.3.5【throws和throw的区别、自定义异常】

 

 

package day4.haifei03;

/*
3.7 自定义异常
    public class 自定义异常类名 extends Exception {
        无参构造
        有参构造
    }

3.8 throws和throw的区别
 */
public class ScoreException extends Exception{

    public ScoreException(){}

    public ScoreException(String message){
        super(message); //将message传给父类
    }

}

package day4.haifei03;

public class Teacher {

    public void checkScore(int score) throws ScoreException{
        if(score<0 || score>100){
            //注意是throw；记得要方法名处要throws ScoreException，不然红色波浪线警告
//            throw new ScoreException(); //无参构造
            throw new ScoreException("输入分数有误"); //有参构造
        }else {
            System.out.println("分数正常");
        }
    }

}

package day4.haifei03;

import java.util.Scanner;

public class TeacherDemo {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入分数：");
        int score = sc.nextInt();

        Teacher t = new Teacher();
        try {
            t.checkScore(score); //编译时异常 try-catch显示处理
        } catch (ScoreException e) {
            e.printStackTrace();
        }

        /*请输入分数：
        222
        day4.haifei03.ScoreException
        at day4.haifei03.Teacher.checkScore(Teacher.java:7)
        at day4.haifei03.TeacherDemo.main(TeacherDemo.java:13)*/

        /*请输入分数：
        -44
        day4.haifei03.ScoreException: 输入分数有误
        at day4.haifei03.Teacher.checkScore(Teacher.java:9)
        at day4.haifei03.TeacherDemo.main(TeacherDemo.java:13)*/
    }
}