Question

Hi i have a Map<Str1,Str2> and i need to get the array of str2 where

str1=="foo"

how can i do that?

thanks

Answer 1

Since java.util.Map is not a multi-map, then the entry having “foo” as a key, if it exists, it’s unique. So I don’t see why you should get a String[].

Just do: String str2 = map.get("foo") and always check if str2 != null before referring to it later.

If you are interested in a multi-map (many entries for a key), then search Apache Commons Collections for it, or you can implement a multi-map yourself very easily, mapping any String key to a Collection of Strings. It’s easy and it works. Choose the right Collection depending on how much frequently it is changed, if you need it sorted, etc… Often a LinkedList is fairly good.