Enumerated valueof() method stepping on the pit

It was used valueOf() Method matching enumeration , Sometimes when you create a new enumeration , Just report that enumeration cannot be found , The root cause lies in the wrong understanding of this method , The parameters of this method do not refer to the values of some fields defined in the enumeration , It is simply enumeration , as follows ：

What matches is the value of the red box , Not inside "A", The two display values are sometimes defined the same , So it will cause misunderstanding , Cause misuse .