I have two tables has one to one relationship as below:
@Entity
@Data
@NoArgsConstructor
@AllArgsConstructor
public class Book {
@Id
@GeneratedValue(strategy = GenerationType.TABLE)
private int id;
private String name;
@OneToOne(cascade = CascadeType.ALL)
@JoinColumn(name = "book_dtail_id")
private BookDetail bookDetail;
}
@Entity
@Table(name = "book_detail")
@Data
@NoArgsConstructor
@AllArgsConstructor
public class BookDetail {
@Id
@GeneratedValue(strategy = GenerationType.TABLE)
private Integer id;
@Column(name = "number_of_pages")
private Integer numberOfPages;
@OneToOne(mappedBy = "bookDetail")
private Book book;
}
I used a Form to input data as below
@Data
@NoArgsConstructor
@AllArgsConstructor
public class BookForm {
Book book;
BookDetail bookDetail;
}
The controller looks like this:
String handleNewBook(Model model){
Book book = new Book();
BookDetail bookDetail = new BookDetail();
BookForm bookForm = new BookForm(book, bookDetail);
model.addAttribute("bookForm", bookForm);
return "index";
}
String handleSaveBookCreate(BookForm bookForm, Model model){
bookForm.getBook().setBookDetail(bookForm.getBookDetail());
bookForm.getBookDetail().setBook(bookForm.getBook());
bookService.save(bookForm.getBook()));
return "index";
}
Last is my form as below:
<form role="form" action="#" th:object="${bookForm}" th:action="@{/book}" method="POST">
<input type="text" th:field="*{book.name}"/>
<input type="text" th:filed="*{bookDetail} == null ? '' : *{bookDetail.numberOfPages}" placeholder="Enter Book Page Numbers"/>
<button type="submit">Submit</button>
</form>
everything seems no problems, but when I "bookService.save(bookForm.getBook()));" is executed, I got error as below
java.lang.StackOverflowError: null,
at com.zangland.study.jpa.entity.BookDetail.hashCode(BookDetail.java:17) ~[classes/:na]
at com.zangland.study.jpa.entity.Book.hashCode(Book.java:16) ~[classes/:na]
at com.zangland.study.jpa.entity.BookDetail.hashCode(BookDetail.java:17) ~[classes/:na]
at com.zangland.study.jpa.entity.Book.hashCode(Book.java:16) ~[classes/:na]
repeat the same as above about 100 lines.... do this mean that I can't use Lombok.hashCode?
Saved Book: '32768','Spring JPA','32768' Saved BookDetail: '32768','1157'
You have a circular dependency between book and bookdetails. You probably need to exclude book
from BookDetail
or bookDetail
from Book
.
You can add @EqualsAndHashCode(exclude="book")
. For more information, see the EqualsAndHashCode documentation.