Spring/JPA [14] 책 게시판 3-(2) : Spring boot

totwo·2024년 9월 23일

AISCHOOL2024 JPA Java Spring

Spring/JPA

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14/17

책 정보 수정 (1)

HomeController

    // 책 수정 화면 이동
    @GetMapping("/modify/{id}")
    public String modify(@PathVariable Long id, Model model){
        Book book = bookService.findById(id);
        model.addAttribute("book", book);
        return "modify"; // modify.html
    }

modify.html

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>modify</title>
</head>
<body>
  <h3>책 수정</h3>
  <form th:action="@{/modify}" method="post">
      <input type="hidden" name="id" th:value="${book.id}">
      <table border="1">
          <tr>
              <td>번호</td>
              <td th:text="${book.id}">ID</td>
          </tr>
          <tr>
              <td>제목</td>
              <td><input type="text" name="title" th:value="${book.title}"/></td>
          </tr>
          <tr>
              <td>가격</td>
              <td><input type="number" name="price" th:value="${book.price}"/></td>
          </tr>
          <tr>
              <td>저자</td>
              <td><input type="text" name="author" th:value="${book.author}"/></td>
          </tr>
          <tr>
              <td>페이지</td>
              <td><input type="number" name="page" th:value="${book.page}"/></td>
          </tr>
          <tr>
              <td colspan="2">
                  <button type="submit">수정</button>
                  <button type="reset">취소</button>
              </td>
          </tr>
      </table>
  </form>
</body>
</html>

BookService

    public Book update(Book book){
        Optional<Book> optional=bookRepository.findById(book.getId());
        if(optional.isPresent()){
            Book dbbook=optional.get(); // DB에서 가져온 Book
            dbbook.setTitle(book.getTitle());
            dbbook.setPrice(book.getPrice());
            dbbook.setAuthor(book.getAuthor());
            dbbook.setPage(book.getPage());
            bookRepository.save(dbbook); // update SQL : 설명
            return dbbook;
        }else{
            throw new RuntimeException("Book not found with id:"+book.getId());
        }
    }

HomeController

    // 책 수정
    @PostMapping("/modify")
    public String modify(Book book){ // book.id(2) -> id가 있으면 update, 없으면 ?
        bookService.update(book);
        return "redirect:/list";
    }

책 정보 수정 (2)

BookService

    public Book update(Long id, Book book){
        Optional<Book> optional=bookRepository.findById(id);
        if(optional.isPresent()){
            Book dbbook=optional.get(); // DB에서 가져온 Book
            dbbook.setTitle(book.getTitle());
            dbbook.setPrice(book.getPrice());
            dbbook.setAuthor(book.getAuthor());
            dbbook.setPage(book.getPage());
            bookRepository.save(dbbook); // update SQL : 설명
            return dbbook;
        }else{
            throw new RuntimeException("Book not found with id:"+id);
        }
    }

HomeController

    // 책 수정
    @PostMapping("/modify/{id}")
    public String modify(@PathVariable Long id, Book book){  
        bookService.update(id, book);
        return "redirect:/list";
    }

modify.html

hidden 지우기
id pathvarible로 넘기기

  <h3>책 수정</h3>
  <form th:action="@{/modify/{id}(id=${book.id})}" method="post">

BookService

save 지워도 더티체킹을 통해 수정이 가능하다
Transactional annotation 필수!!

    @Transactional
    public Book update(Long id, Book book){
        Optional<Book> optional=bookRepository.findById(id);
        if(optional.isPresent()){
            Book dbbook=optional.get(); // DB에서 가져온 Book
            dbbook.setTitle(book.getTitle());
            dbbook.setPrice(book.getPrice());
            dbbook.setAuthor(book.getAuthor());
            dbbook.setPage(book.getPage());
            // bookRepository.save(dbbook); // update SQL : 설명
            return dbbook; // 리턴하여 controller로 보낼 때 수정이 됨 (더티체킹) - 성능저하
        }else{
            throw new RuntimeException("Book not found with id:"+id);
        }
    }