java:use 'Map' as value in another Java Map

Question

I want to store a list of triad and my syntax is:

Map<Integer, Map<Integer, Integer> > map;

map = new HashMap<Integer, TreeMap<Integer, Integer> >();

Then Java said:

Type mismatch: cannot convert from HashMap<Integer,TreeMap<Integer,Integer>> to Map<Integer, Map<Integer,Integer>>

What could I do?

You should declare `map` variable a `HasMap`: `HashMap > map;` `map = new HashMap >();` — Halil İbrahim Oymacı, Jun 30 '16 at 13:06
The duplicate question is about lists rather than maps, but the explanation is the same. — Andy Turner, Jun 30 '16 at 13:07

score 0 · Answer 1 · answered Jun 30 '16 at 13:06

0

You can simply type

map = new HashMap<>();

answered Jun 30 '16 at 13:06

Patrick

1 Answers1