Convert a Map<String, List<String>> to Map<String, Object[]>

Question

Is there a better way to convert a Map<String, List<String>> to Map<String, Object[]> or vice versa other than a for loop? By better, I mean using any library or Lambda expressions

Answer 1

I tried this way as mentioned in In Java 8 how do I transform a Map to another Map using a lambda?

final Map<String, List<String>> listMap = new HashMap<>();
listMap.put("Dog", Arrays.asList("Boxer","Julie"));
listMap.put("Cat", Arrays.asList("Cat1","Cat2"));

Map<String,Object[]> objectMap = listMap.entrySet().stream()
    .collect(Collectors.toMap(e->e.getKey(), e->e.getValue().toArray()));

This worked. Is there any issue with this code or can it be further improved?

Answer 2

It is possible to create a custom Map class that overrides the appropriate methods in the java.util.Map interface to handle "lazy" conversions.

Such a class would be initialized with the Map<String, List<String>> or Map<String, Object[]> object and operate as a native Map<String, Object[]> or Map<String, List<String>> , respectively.