Java 自定义异常、手动抛出异常

package test;



import java.util.Map;

import java.util.Scanner;

import java.util.TreeMap;



public class Test {

    public static void main(String[] args) throws Exception {

        Scanner input = new Scanner(System.in);

        String str = input.next();

        if("y".equals(str)||"n".equals(str)){

            System.out.println(str);

        }else{

            throw new Exception("输入异常");

        }

    }

}