FunctionInterfaceExample.java

package com.kiroule.ocpupgradejava8.topic2_2;

import java.util.Arrays;
import java.util.List;
import java.util.function.Function;

/**
 * @author Igor Baiborodine
 */
public class FunctionInterfaceExample {

  public static void main(String... args) {

    List<FuturamaCharacter> characters = Arrays.asList(
        new FuturamaCharacter("Bender", "Rodriguez"),
        new FuturamaCharacter("Philip", "Fry"),
        new FuturamaCharacter("Turanga", "Leela"));

    System.out.println("Full names:");
    for (FuturamaCharacter character : characters) {
      System.out.println(character.getFullName(
          c -> c.getFirstName() + " " + c.getLastName()
      ));
    }
    System.out.println("\nInverted full names:");
    characters.forEach(c -> System.out.println(c.getFullName(new InvertedFullNameFunction())));
  }
}

class InvertedFullNameFunction implements Function<FuturamaCharacter, String> {

  @Override
  public String apply(FuturamaCharacter c) {
    return c.getLastName() + ", " + c.getFirstName();
  }
}

class FuturamaCharacter {

  private String firstName;
  private String lastName;

  public FuturamaCharacter(String firstName, String lastName) {
    this.firstName = firstName;
    this.lastName = lastName;
  }

  public String getFullName(Function<FuturamaCharacter, String> function) {
    return function.apply(this);
  }

  public String getFirstName() {
    return firstName;
  }

  public String getLastName() {
    return lastName;
  }
}