HashMap with multiple values under the same key

Question

Is it possible for us to implement a HashMap with one key and two values. Just as HashMap?

Please do help me, also by telling (if there is no way) any other way to

Answer 1

The easiest way would be to use a google collection library:

import com.google.common.collect.ArrayListMultimap;
import com.google.common.collect.Multimap;

public class Test {

    public static void main(final String[] args) {

        // multimap can handle one key with a list of values
        final Multimap cars = ArrayListMultimap.create();
        cars.put("Nissan", "Qashqai");
        cars.put("Nissan", "Juke");
        cars.put("Bmw", "M3");
        cars.put("Bmw", "330E");
        cars.put("Bmw", "X6");
        cars.put("Bmw", "X5");

        cars.get("Bmw").forEach(System.out::println);

        // It will print the:
        // M3
        // 330E
        // X6
        // X5
    }

}

maven link: https://mvnrepository.com/artifact/com.google.collections/google-collections/1.0-rc2

more on this: http://tomjefferys.blogspot.be/2011/09/multimaps-google-guava.html