NullPointerException: object reference not set to an object
The NullPointerException is a common runtime exception in Java, which occurs when you try to use a null object.
A null object refers to a variable that has been assigned the value null. When you try to access or call methods on such a null object, Java throws a NullPointerException.
To avoid this error, always check if an object is null before using it.
还没有评论,来说两句吧...