异常在子父类覆盖中的体现；

1，子类在覆盖父类时，如果父类的方法抛出异常，那么子类的覆盖方法，只能抛出父类的异常或者该异常的子类。

2，如果父类方法抛出多个异常，那么子类在覆盖该方法时，只能抛出父类异常的子集。

3，如果父类或者接口的方法中没有异常抛出，那么子类在覆盖方法时，也不可以抛出异常。

　　如果子类方法发生了异常。就必须要进行try处理。绝对不能抛。-Abnormalities in the child in the parent class overrides reflected　1 subclasses override the parent, if the parent class method throws an exception, then the subclass override method, only the parent class throws an exception or a subclass of the exception . 2, if the parent class method throws multiple exceptions, then subclasses override this method, you can only throw an exception subset of the parent class. 3, if the parent class or interface method does not throw an exception, then the subclass overriding a method, it can not throw an exception. If the sub-class method of the exception. We must try to be processed. Absolutely can not throw.