自定义异常

1.自定义异常继承Exception，需继承父类Exception的无参构造和有参构造，自定义异常方法。

public class MyException extends Exception {
    public MyException(){
        super();
    };

    public MyException(String message){
        super(message);
    }

    public void validate(String input) throws MyException {
        if(input.equals("abc")){
            throw new MyException("输入不合法");
        }
    }
}

2.编写测试类

import java.util.Scanner;

public class Test {
    public static void main(String[] args){
        MyException myException = new MyException();
        Scanner sc = new Scanner(System.in);
        String input = sc.next();
        try {
            myException.validate(input);
        }catch (MyException e){
            e.printStackTrace();
        }



    }
}

3.结果输出