July 07, 2022
01.이터레이터 패턴이란?
02.코드로 알아보는 패턴
02.1 Client.java
02.2 Board.java
02.3 Post.java
03.문제
package me.whiteship.designpatterns._03_behavioral_patterns._16_iterator._01_before;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
public class Client {
public static void main(String[] args) {
Board board = new Board();
board.addPost("디자인 패턴 게임");
board.addPost("선생님, 저랑 디자인 패턴 하나 학습하시겠습니까?");
board.addPost("지금 이 자리에 계신 여러분들은 모두 디자인 패턴을 학습하고 계신 분들입니다.");
// TODO 들어간 순서대로 순회하기
List<Post> posts = board.getPosts();
for (int i = 0 ; i < posts.size() ; i++) {
Post post = posts.get(i);
System.out.println(post.getTitle());
}
// TODO 가장 최신 글 먼저 순회하기
Collections.sort(posts, (p1, p2) -> p2.getCreatedDateTime().compareTo(p1.getCreatedDateTime()));
for (int i = 0 ; i < posts.size() ; i++) {
Post post = posts.get(i);
System.out.println(post.getTitle());
}
}
}
package me.whiteship.designpatterns._03_behavioral_patterns._16_iterator._01_before;
import java.util.ArrayList;
import java.util.List;
import java.util.Set;
public class Board {
List<Post> posts = new ArrayList<>();
public List<Post> getPosts() {
return posts;
}
public void setPosts(List<Post> posts) {
this.posts = posts;
}
public void addPost(String content) {
this.posts.add(new Post(content));
}
}
package me.whiteship.designpatterns._03_behavioral_patterns._16_iterator._01_before;
import java.time.LocalDateTime;
public class Post {
private String title;
private LocalDateTime createdDateTime;
public Post(String title) {
this.title = title;
this.createdDateTime = LocalDateTime.now();
}
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public LocalDateTime getCreatedDateTime() {
return createdDateTime;
}
public void setCreatedDateTime(LocalDateTime createdDateTime) {
this.createdDateTime = createdDateTime;
}
}