Create only 1 list from a map where map value is list using JAVA 8 Streams

Question

I have a Map, where the \"value\" is a List of projects:

Map> projectsMap = ...

I want to extract from the map

Answer 1

Thanks @Holger for the answer.

List projects = projectsMap.values().stream().flatMap(List::stream)
.collect(‌​Collectors.toList())‌​;

Code to avoid NullPointerException in case a Collection in the value map is Null:

projectsMap.values().stream().filter(Objects::nonNull)
.flatMap(List::stream).collect(Collectors.toList());