How to convert List<AnyClassObject> to List<Map<String, String>> using Stream in java 8?

I have a List, I need to convert it to List<Map<String, String>>.

For e.g. consider below scenario:

public class AnyClass() {

    private String letter;

}

Now, suppose I have a list objectList which have multiple object with diff value of letter

List<AnyClass> objectList = new ArrayList();
objectList.add(new AnyClass("A"));
objectList.add(new AnyClass("B"));
objectList.add(new AnyClass("C"));
objectList.add(new AnyClass("D"));

now I want to convert it to List<Map<String, String>> using Stream in java 8.

I want to achieve the following:

List<Map<String, String>> listOfMaps = new ArrayList<>();

for(AnyClass object: objectList) {
    listOfMaps.add(ImmutableMap.<String, String>builder()
                    .put("ConstantKey","ConstantValue")
                    .put("ConstatKey2", object.getLetter())
                    .build());
}

>Solution :

It’s a simple map() and collect():

List<Map<String, String>> listOfMaps = objectList.stream()
        .map(o -> ImmutableMap.of(
                "ConstantKey", "ConstantValue",
                "ConstantKey2", o.getLetter()))
        .collect(Collectors.toList());

You might want to extract the map construction to a separate method to keep the lambda a little cleaner.