Merge Two Guava Multimaps

Question

Is there a way to elegantly merge two guava multimaps with the same key value pairs in java 8?

I have tried using .collect(Multimaps.toMultimap()) with no luck.

What's wrong with `putAll()`? – shmosel Jul 25 '18 at 20:18 — shmosel, Jul 25 '18 at 20:18
Sorry should have said flatten a list of Multimaps. – Jul 25 '18 at 20:32 — , Jul 25 '18 at 20:32

score 6 · Accepted Answer · answered Jul 25 '18 at 20:48

6

There are a few ways; this is the cleanest one I could find:

list.stream().collect(ArrayListMultimap::create, Multimap::putAll, Multimap::putAll)

Feel free to replace ArrayListMultimap with some other implementation.

answered Jul 25 '18 at 20:48

shmosel

1 Answers1