JDBC - 7. article list 시, 데이터를 DB로부터 가져오기

Ⅶ. article list 시, 데이터를 DB로부터 가져오기

1. article list 시, 데이터를 DB로부터 가져오기

 - Main.java에 다음과 같이 입력

 - article list 시, 데이터를 DB로부터 가져와서 출력함

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);

		System.out.println("==프로그램 시작==");

		int lastArticleId = 0;

		while (true) {

			System.out.printf("명령어 ) ");
			String cmd = sc.nextLine().trim();

			if (cmd.equals("exit")) {
				System.out.println("===종료===");
				break;
			}

			if (cmd.equals("article write")) {
				System.out.println("== 게시물 작성 ==");
				int id = lastArticleId + 1;
				System.out.printf("제목 : ");
				String title = sc.nextLine();
				System.out.printf("내용 : ");
				String body = sc.nextLine();

				System.out.printf("%d번글이 생성되었습니다\n", id);
				System.out.println("title : " + title);
				System.out.println("body : " + body);

				Article article = new Article(id, title, body);

				Connection conn = null;
				PreparedStatement pstmt = null;

				try {
					Class.forName("com.mysql.jdbc.Driver");
					String url = "jdbc:mysql://127.0.0.1:3306/JDBCTest?useUnicode=true&characterEncoding=utf8&autoReconnect=true&serverTimezone=Asia/Seoul&useOldAliasMetadataBehavior=true&zeroDateTimeNehavior=convertToNull";

					conn = DriverManager.getConnection(url, "root", "");
					System.out.println("연결 성공!");

					String sql = "INSERT INTO article";
					sql += " SET regDate = NOW()";
					sql += ", updateDate = NOW()";
					sql += ", title = '" + title + "'";
					sql += ", `body` = '" + body + "';";

					System.out.println(sql);
					pstmt = conn.prepareStatement(sql);

					int affectedRows = pstmt.executeUpdate();

					System.out.println(affectedRows + "열에 적용됨");

				} catch (ClassNotFoundException e) {
					System.out.println("드라이버 로딩 실패");
				} catch (SQLException e) {
					System.out.println("에러: " + e);
				} finally {
					try {
						if (conn != null && !conn.isClosed()) {
							conn.close();
						}
					} catch (SQLException e) {
						e.printStackTrace();
					}
					try {
						if (pstmt != null && !pstmt.isClosed()) {
							pstmt.close();
						}
					} catch (SQLException e) {
						e.printStackTrace();
					}
				}

				lastArticleId++;

			} else if (cmd.equals("article list")) {
				System.out.println("== 게시물 리스트 ==");

				Connection conn = null;
				PreparedStatement pstmt = null;
				ResultSet rs = null;

				List<Article> articles = new ArrayList<>();

				try {
					Class.forName("com.mysql.jdbc.Driver");
					String url = "jdbc:mysql://127.0.0.1:3306/JDBCTest?useUnicode=true&characterEncoding=utf8&autoReconnect=true&serverTimezone=Asia/Seoul&useOldAliasMetadataBehavior=true&zeroDateTimeNehavior=convertToNull";

					conn = DriverManager.getConnection(url, "root", "");
					System.out.println("연결 성공!");

					String sql = "SELECT *";
					sql += " FROM article";
					sql += " ORDER BY id DESC";

					System.out.println(sql);

					pstmt = conn.prepareStatement(sql);
					rs = pstmt.executeQuery();

					while (rs.next()) {
						int id = rs.getInt("id");
						String regDate = rs.getString("regDate");
						String updateDate = rs.getString("updateDate");
						String title = rs.getString("title");
						String body = rs.getString("body");

						Article article = new Article(id, regDate, updateDate, title, body);
						articles.add(article);
					}

				} catch (ClassNotFoundException e) {
					System.out.println("드라이버 로딩 실패");
				} catch (SQLException e) {
					System.out.println("에러: " + e);
				} finally {
					try {
						if (rs != null && !rs.isClosed()) {
							rs.close();
						}
					} catch (SQLException e) {
						e.printStackTrace();
					}
					try {
						if (pstmt != null && !pstmt.isClosed()) {
							pstmt.close();
						}
					} catch (SQLException e) {
						e.printStackTrace();
					}
					try {
						if (conn != null && !conn.isClosed()) {
							conn.close();
						}
					} catch (SQLException e) {
						e.printStackTrace();
					}
				}

				if (articles.size() == 0) {
					System.out.println("게시물이 없습니다");
					continue;
				}

				System.out.println("번호    |    제목");

				for (int i = 0; i < articles.size(); i++) {
					Article article = articles.get(i);
					System.out.printf("%4d    |    %s\n", article.id, article.title);
				}
			}

		}
	}
}