用户自定义异常类

如何自定义异常类？

继承于现有的异常结构：RuntimeException 、Exception
提供全局常量：serialVersionUID
提供重载的构造器

package com.atguigu.java2;
/** 如何自定义异常类？* 1. 继承于现有的异常结构：RuntimeException 、Exception* 2. 提供全局常量：serialVersionUID* 3. 提供重载的构造器* */
public class MyException extends Exception{static final long serialVersionUID = -7034897193246939L;public MyException(){}public MyException(String msg){super(msg);}
}

package com.atguigu.java2;public class StudentTest {public static void main(String[] args) {try {Student s = new Student();s.regist(-1001);System.out.println(s);} catch (Exception e) {
//			e.printStackTrace();System.out.println(e.getMessage());}}}class Student{private int id;public void regist(int id) throws Exception {if(id > 0){this.id = id;}else{
//			System.out.println("您输入的数据非法！");//手动抛出异常对象
//			throw new RuntimeException("您输入的数据非法！");
//			throw new Exception("您输入的数据非法！");throw new MyException("不能输入负数");//错误的
//			throw new String("不能输入负数");}}@Overridepublic String toString() {return "Student [id=" + id + "]";}}