Excuse me, I have two questions about the Listing 6.1 of page. 204

1.I have seen the errata list. There is a correction in Listing 6.1 of page. 204



Maybe my English is too poor to realize the meaning of "switch the lines" ,
could anyone please tell me what the "switch the lines" actully means?

2.In the method "nullsafeSet", there are some codes like follows:


Why could the object "value" directly cast into an object of type "MonetaryAmount"
and use anyCurrency as a parameter of method "convert"?

Does class "MonetaryAmount" have any relationship with class "BigDecimal"?

Thanks for all your reply.

Switch means move A to B and B to A position.

Also, I think you are getting very distracted by implementation details of the MonetaryAmountUserType. It doesn't make sense if you don't understand the context that is explained, that is UserTypes in general. It doesn't really matter what you or I implement in these methods, as long as you understand when they are useful.