Question

I have many maps like Map(String, Object).

map1
map2
....
mapN

I need to receive map that contains only these key-value pairs where first parameter is equal in all maps.
Could it be done by using retainAll method?

Answer 1

Yes you can do it using retainAll

map1.keySet().retainAll(map2.keySet());
map1.keySet().retainAll(map3.keySet()); //etc

At last map1 will be intersection of all keys in your all maps so these keys are common now you can retrieve value easily