guava one-key multi-value map

 

public static void main(String[] args) {
    Multimap<Integer, String> map = LinkedListMultimap.create();
    map.put(1, "xue");
    map.put(1, "wang");
    map.put(1, "zhang");
    map.put(1, "zhang");
    System.out.println("size:"+map.size());
    System.out.println(map);
    System.out.println(map.get(1));
  }
  // output
size:4
{1=[xue, wang, zhang, zhang]}
[xue, wang, zhang, zhang]

 

wrote

Other variants of Multimap, the same as the meaning in the name, are suitable for different situations, as long as you choose the best choice when using:

1.ArrayListMultimap:

2.ForwardingMultimap:

3.HashMultimap:

4.ImmutableListMultimap:

5.ImmutableMultimap:

6. ImmutableSetMultimap:

7.LinkedHashMultimap:

8.LinkedListMultimap:

9.TreeMultimap.