getting last element from a linked hashmap returned from dao layer?

Question

I have LinkedHashMap returning from db. From this map i need to get exactly last element(key). If i get all keys using keySet method it returns Set of keys but Set does not guarantee the order. i need to take exactly last key from the linked hashmap returned from db. how can i do that ?

below is the code how i get data from data base.

LinkedHashMap<String,String> map = someDao.getMap(String input);

from this map i need to take last element.

Thanks!

Answer 1

keySet() being executed on LinkedHashMap returns LinkedHashSet that is indeed Set but "remembers" the order of elements.

You can get the last element as following:

Map<TheType> map = .....
.................
TheType theLastKey = new ArrayList<>(map.keySet()).get(map.size() - 1)

Answer 2

Answer from a different post helped me with this answer. Pls refer Java HashMap: How to get a key and value by index? for the original post.

Object myKey = myHashMap.keySet().toArray()[0];

where i have replaced the 0

toArray()[0]  - (where 0 represents the first item in the keyset)

with the size of the keyset

toArray()[(keyset().size)-1] 

Note : Without the -1 at the end, you would get a ArrayIndexOutOfBoundsException.