用户自定义异常类

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");
        }
    }
    @Override
    public String toString() {
        return "Student [id=" + id + "]";
    }
}

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 RuntimeException{
    static final long serialVersionUID = -7034897193246939L;
    public MyException() {
    }
    public MyException(String msg) {
        super(msg);
    }
}