public class User {

    private int id;

    private String name;

    public User(int id, String name) {

    this.id = id;

    this.name = name;

    }

    public int getId() {

        return id;

    }

    public void setId(int id) {

        this.id = id;

    }

    public String getName() {

        return name;

    }

    public void setName(String name) {

        this.name = name;

    }

}

import java.util.ArrayList;

import java.util.List;

public class ConstrMethodRef {

    @FunctionalInterface

    interface UserFactory<U extends User>{

    U create(int id, String name);

    }

    static UserFactory<User> uf = User::new;

    public static void main(String[] args) {

    List<User> users = new ArrayList<User>();

    for(int i=0; i<10; i++) {

        users.add(uf.create(i, "billy" + Integer.toString(i)));

    }

    users.stream().map(User::getName).forEach(System.out::println);

    }

}