StaticInnerClassExample.java

package com.kiroule.ocpupgradejava8.topic1_1;

import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;

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

  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("Before sorting: " + characters);

    FuturamaCharacter.FirstNameAscComparator
        comparator =
        new FuturamaCharacter.FirstNameAscComparator();
    Collections.sort(characters, comparator);
    System.out.println("After sorting: " + characters);
  }
}

class FuturamaCharacter {

  private String firstName;
  private String lastName;

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

  static class FirstNameAscComparator implements Comparator<FuturamaCharacter> {

    @Override
    public int compare(FuturamaCharacter o1, FuturamaCharacter o2) {
      return o1.getFirstName().compareTo(o2.getFirstName());
    }
  }

  public String getFirstName() {
    return firstName;
  }

  @Override
  public String toString() {
    return firstName + " " + lastName;
  }
}