Scala conversion long to datetime

Question

I am using nscala-time (wrapper for Joda Time) and slick for a project. I\'m trying to use this clause to write a line to the database:

Article.insert(0,\"ti         


        

Answer 1

You misunderstand what asInstanceOf does: asInstanceOf doesn't convert anything. What it does is lie to the compiler, telling it to believe something instead of going with the knowledge it has.

So, you had a Long, and then you got a Long, but pretended it was a Timestamp, which obviously doesn't work.

I have a simple recommendation regarding asInstanceOf: never use it.

Answer 2

There's no magic about it. Your first statement:

DateTime.now.getMillis

is a Long. A Long is not a Timestamp, so it makes sense that you can't convert it to one by using asInstanceOf.

The second statement:

new Timestamp(dateTime.getMillis())

is using the Timestamp constructor to create a new Timestamp instance based on the dateTime.getMillis.