Merge Map Java 8 Stream

Question

I would like to merge two Map with JAVA 8 Stream:

Map> mapGlobal = new HashMap>();
Map

        

Answer 1

Using StreamEx

Map> mergedMap =
        EntryStream.of(mapGlobal)
                .append(EntryStream.of(mapAdded))
                .toMap((v1, v2) -> {
                    List combined = new ArrayList<>();
                    combined.addAll(v1);
                    combined.addAll(v2);
                    return combined;
                });

If you have even more maps to merge just append to the stream

                .append(EntryStream.of(mapAdded2))
                .append(EntryStream.of(mapAdded3))