Я работал с проектом Spring Boot, который читает файлы CSV и сохраняет данные в базе данных H2.
Файлы CSV представлены ниже -
authors.csv
email;firstname;lastname
null-walter@echocat.org;Paul;Walter
null-mueller@echocat.org;Max;Mülle
books.csv
title;isbn;bookAuthors;description
Ich helfe dir kochen. Das erfolgreiche Universalkochbuch mit großem Backteil;5554-5545-4518;null-walter@echocat.org,boby-walter@echocat.org;Auf der Suche nach einem Basiskochbuch steht man heutzutage vor einer Fülle von Alternativen. Es fällt schwer, daraus die für sich passende Mixtur aus Grundlagenwerk und Rezeptesammlung zu finden. Man sollte sich darüber im Klaren sein, welchen Schwerpunkt man setzen möchte oder von welchen Koch- und Backkenntnissen man bereits ausgehen kann.
magazines.csv
title;isbn;bookAuthors;publishedAt
Beautiful cooking;5454-5587-3210;null-walter@echocat.org;21.05.2011
Я пишу POJOфайлы,
@Entity
@Table(name = "Author")
public class Author implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.TABLE)
private Long id;
// email;firstname;lastname
@Column
private String email;
@Column
private String firstname;
@Column
private String lastname;
@ManyToMany(mappedBy = "bookAuthors", fetch = FetchType.LAZY)
List<Book> books;
@ManyToMany(mappedBy = "bookAuthors", fetch = FetchType.LAZY)
List<Magazine> magazines;
public Author() {
}
public Author(String email, String firstname, String lastname) {
this.email = email;
this.firstname = firstname;
this.lastname = lastname;
}
}
@Entity
@Table(name = "Book")
public class Book implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
// title;isbn;bookAuthors;description
@Column
private String title;
@Column
private String isbn;
@Column(length = 5000)
private String description;
@ElementCollection
@Column(name="bookAuthors")
List<String> bookAuthors;
@ManyToMany(fetch = FetchType.EAGER)
@JoinTable(
name = "book_authors",
joinColumns = @JoinColumn(name = "book_id"),
inverseJoinColumns = @JoinColumn(name = "author_id"))
List<Author> authors;
public Book() {
}
public Book(String title, String isbn, String description) {
this.title = title;
this.isbn = isbn;
this.description = description;
}
}
@Entity
@Table(name = "Magazine")
public class Magazine implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
// title;isbn;bookAuthors;publishedAt
@Column
private String title;
@Column
private String isbn;
@ElementCollection
@Column(name = "bookAuthors")
List<String> bookAuthors;
@Column
private String publishedAt;
@ManyToMany(fetch = FetchType.EAGER)
@JoinTable(
name = "magazine_authors",
joinColumns = @JoinColumn(name = "magazine_id"),
inverseJoinColumns = @JoinColumn(name = "author_id"))
List<Author> authors;
public Magazine() {
}
public Magazine(String title, String isbn, String publishedAt) {
this.title = title;
this.isbn = isbn;
this.publishedAt = publishedAt;
}
}
Приведены примеры файлов хранилища и сервисных файлов,
@Repository
public interface BookRepository extends JpaRepository<Book, Long> {
@Query(value = "SELECT * FROM book WHERE book.isbn=:isbn",nativeQuery = true)
Optional<Book> findBookByIsbn(String isbn);
}
Сервисный файл,
@Service
public class BookService {
private BookRepository repository;
@Autowired
public void setBookRepository(BookRepository BookRepository) {
this.repository = BookRepository;
}
@Transactional(rollbackFor = Exception.class)
public Optional<Book> findById(Long id) {
return repository.findById(id);
}
@Transactional(rollbackFor = Exception.class)
public List<Book> findAll() {
return (List<Book>) repository.findAll();
}
@Transactional(rollbackFor = Exception.class)
public Book save(Book Product) {
return repository.save(Product);
}
@Transactional
public <S extends Book> List<Book> saveAll(List<Book> students) {
List<Book> result = new ArrayList<>();
if (students == null) {
return result;
}
for (Book student : students) {
result.add(repository.save(student));
}
return result;
}
@Transactional(rollbackFor = Exception.class)
public void deleteAll() {
repository.deleteAll();
}
@Transactional(rollbackFor = Exception.class)
public Optional<Book> findBookByIsbn(String isbn){
return repository.findBookByIsbn(isbn);
}
}
Когда я пытался сохранитьДанные книги, я пишу код,
String bookFilePath = "/Users/Chaklader/IdeaProjects/Publications/src/main/resources/data/books.csv";
List<Book> books = new BookCsvFileReader(authorService).readBooksCsvData(bookFilePath);
bookService.saveAll(books);
Я получаю ошибку,
Caused by: org.h2.jdbc.JdbcSQLException: Data conversion error converting "'null-walter@echocat.org' (AUTHOR: ID BIGINT NOT NULL)"; SQL statement:
insert into book_book_authors (books_id, book_authors) values (?, ?) [22018-196]
Как я могу исправить это?
Обновление
BookCsvFileRead.java
public class BookCsvFileReader extends CsvFileReader {
private AuthorService authorService;
public BookCsvFileReader(AuthorService service) {
this.authorService = service;
}
public List<Book> readBooksCsvData(String fileName) throws IOException {
List<Book> books = new ArrayList<>();
try {
List<List<String>> lines = CsvFileReader.readCsvFile(fileName);
lines.remove(0);
for (List<String> line : lines) {
String title = line.get(0);
String isbn = line.get(1);
String[] emails = line.get(2).split(",");
List<String> bookAuthors = new ArrayList<>();
for (String email : emails) {
bookAuthors.add(email);
}
String description = line.get(3);
Book book = new Book(title, isbn, description, bookAuthors);
book.setBookAuthors(bookAuthors);
books.add(book);
}
}
//
catch (IOException e) {
e.printStackTrace();
}
return books;
}
}