将Java7迁移到Java8-forEach中的forEach，以获得HashMap中的HashMap？

我的java7代码：

int dataIndex = 0;
final List<DataIndex> indexData = new ArrayList<>();
for (final Entry<Integer, Map<String, ModelList>> e : fusionedData.entrySet()) {
    for (final Entry<String, ModelList> e2 : e.getValue().entrySet()) {
        dataIndex++;
        indexData.add(new DataIndex(dataIndex, e2.getValue().getIds()));
    }
}

我尝试使用stream+map

试试这个：

Map<Integer, Map<Integer, ModelList>> fusionedData;
fusionedData.values() // Collection<Map<Integer, ModelList>
        .stream() // Stream<Map<Integer, ModelList>>
        .flatMap(map -> map.values().stream()) // Stream<ModelList>
        .forEach(value -> {
            // here value is instance of ModelList
            // do something with that
        });

fusionedData.entrySet().stream().map(Map.Entry::getValue)...???

AtomicInteger dataIndex = new AtomicInteger();
final List<DataIndex> indexData = fusionedData.values().stream()
    .flatMap(models-> models.values().stream()) // Stream<ModelList>
    .map(ModelList::getIds)
    .map(ids -> new DataIndex(dataIndex.incrementAndGet(), ids))
    .collect(Collectors.toList());

Map<Integer, Map<Integer, ModelList>> fusionedData;
fusionedData.values() // Collection<Map<Integer, ModelList>
        .stream() // Stream<Map<Integer, ModelList>>
        .flatMap(map -> map.values().stream()) // Stream<ModelList>
        .forEach(value -> {
            // here value is instance of ModelList
            // do something with that
        });