HashMap: iterating the key-value pairs in random order

Question

I have a HashMap and I\'d like to iterate they key-value pairs in a different random order each time i get the iterator. Conceptually I\'d like to \"shuffle\" the map before

Answer 1

Try use concurent hash map and get key by random before iteration cycle

Map map = Maps.newConcurrentMap();

        map.put("1", "1");
        map.put("2", "2");
        Iterator iterator = map.keySet().iterator();
        while (iterator.hasNext()) {
            map.remove("2");// add random key values
            map.put("2", "2");
            String next = iterator.next();
            System.out.println("next" + next);
        }

Random remove/put values can "shuffle" your map