java 8 - is there a good way to filter and remove from a map?

Question

I want to filter several objects from a map as follows:

• Create a new map with the filtered results
• Remove from original map

Currently I do it using two methods

Map<String, MyObject > map = scenarioFieldsMap.entrySet().stream()
            .filter(e -> e.getKey().contains("["))
            .collect(Collectors.toMap(Map.Entry::getKey, e -> e.getValue()));

scenarioFieldsMap.entrySet().removeIf(e -> e.getKey().contains("["));

Is there a better way to filter and remove?

Answer 1

The second step can be more efficient if instead of iterating over all the keys (or entries) you only remove the keys present in the other map :

scenarioFieldsMap.keySet().removeAll(map.keySet());

I'm assuming you meant to remove the entries from the original scenarioFieldsMap and not from the new map that you create in the first step.