LambdaExpressionSortExample.java

package ch02;

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

public class LambdaExpressionSortExample {
 static class Member {
 String name;
 int age;

 public Member(String name, int age) {
 this.name = name;
 this.age = age;
 }

 @Override
 public String toString() {
 return "Member{" +
 "name='" + name + '\'' +
 ", age=" + age +
 '}';
 }
 }

 public static void main(String[] args) {
 // 리스트에 데이터 삽입
 List<Member> members1 = new ArrayList<>();
 members1.add(new Member("윈터", 23));
 members1.add(new Member("카리나", 24));
 members1.add(new Member("닝닝", 22));

 // 정렬을 익명 클래스로 구현
 Collections.sort(members1, new Comparator<Member>() {
 @Override
 public int compare(Member o1, Member o2) {
 return o2.age - o1.age;
 }
 });

 System.out.println(members1);

 // ---

 List<Member> members2 = new ArrayList<>();
 members2.add(new Member("윈터", 23));
 members2.add(new Member("카리나", 24));
 members2.add(new Member("닝닝", 22));

 // 정렬을 람다 표현식으로 구현
 members2.sort((o1, o2) -> o2.age - o1.age);

 System.out.println(members2);
 }
}