Required arguments with a Lombok @Builder

Question

If I add @Builder to a class. The builder method is created.

Person.builder().name(\"john\").surname(\"Smith\").build();

I have a requirem

Answer 1

Take User class as example, id field is required:

@AllArgsConstructor(access = AccessLevel.PRIVATE) // required, see https://stackoverflow.com/questions/51122400/why-is-lombok-builder-not-compatible-with-this-constructor
@NoArgsConstructor(access = AccessLevel.PRIVATE)
@Builder
@Getter
public class User {
    private String id;
    private String name;
    private int age;

    public static UserBuilder builder(final String id) {
        return new UserBuilder().id(id);
    }
}

You can only initialize a User instance by builder like User user = User.builder("id-123").name("Tom").build;. With private no args constructer, you are not able to User user = new User(); or User user = new User("id-123"); so you always need to pass the required parameter id. Please note the initialized instance is immutable.