CODEWITHSUNDEEP
java-8java-stream
Parameswar
Parameswar

Reputation: 2069

Iterate through elements of List - Java 8

I have a List of String, i need to iterate elements and create a new Object for each element in the list and add to a parent list, how do ido in Java 8 , this is what i tried so far:

List<CustomObject> parentList = new ArrayList<>();
List<String> emailList = fromSomeMethod();
emailList().stream().forEach(email -> parentList.add(new CustomObject(email)));

I am getting an error:

"variable used in lambda expression should be final or effectively final"

Any suggestions ? dont want to do it in the old school way, Thanks,

Upvotes: 0

Views: 2796

Answers (3)

Zabihullah Alipour
Zabihullah Alipour

Reputation: 625

Use this:

static class CustomObject {
    String email;

    public CustomObject(String email) {
        this.email = email;
    }
}
private static void test4() {
    List<CustomObject> parentList = new ArrayList<>();
    List<String> emailList = Arrays.asList("[email protected]", "[email protected]");
    emailList.stream()
            .map(CustomObject::new)
            .forEach(parentList::add);
}

Upvotes: 0

soorapadman
soorapadman

Reputation: 4509

Try like this You should have Parameterized Constructor

            public class CustomObject {
                private String email;
                private boolean isFlag;
            //Getter setter
                public CustomObject(String email, boolean isFlag) {
                    this.email = email;
                    this.isFlag = isFlag;
                }
               public CustomObject(String email) {
            this.email = email;
        }

            }
List<CustomObject> parentList = emailList.stream().map(CustomObject::new).collect(Collectors.toList());

Upvotes: 0

Eugene
Eugene

Reputation: 120858

  List<CustomObject> parentList = emailList().stream()
             .map(CustomObject::new)
             .collect(Collectors.toList());

No need to complicated things, just map that and collect to a new List

Upvotes: 1

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