1
「保存（S）」與在 「保存（S）」「org.springframework.data.repository.CrudRepository」存儲庫衝突兩種方法都有 相同擦除，但都不會超越另一個。兩種方法都有相同的擦除，但既沒有覆蓋其他
我得到了這個錯誤。我試圖創建一個名爲BookRepository的接口。該接口擴展CrudRepository，我想在該接口中實現save方法和saveAll方法。當我實現所有方法時，除save（）和saveAll（）之外，所有方法都可以正常工作。
我給你我的課程如下。
BookRepository：
package repositories;
import com.ex.deneme_1.*;
import org.springframework.data.repository.CrudRepository;
import java.util.Optional;
public interface BookRepository extends CrudRepository<Book, Long>{
@Override
default <S extends T> S save(S entity) { // That doesn't work
return null;
}
@Override
default <S extends T> Iterable<S> saveAll(Iterable<S> entities) {
//That doesn't work either
return null;
}
@Override
default Optional<Book> findById(Long id) {
return null;
}
@Override
default boolean existsById(Long id) {
return false;
}
@Override
default Iterable<Book> findAll() {
return null;
}
@Override
default Iterable<Book> findAllById(Iterable<Long> ids) {
return null;
}
@Override
default long count() {
return 0;
}
@Override
default void deleteById(Long id) {
}
@Override
default void delete(Book entity) {
}
@Override
default void deleteAll(Iterable<? extends Book> entities) {
}
@Override
default void deleteAll() {
}
}
我的引導類：
package Bootstrap;
import com.ex.deneme_1.*;
import org.springframework.context.ApplicationListener;
import org.springframework.context.event.ContextRefreshedEvent;
import org.springframework.stereotype.*;
import repositories.*;
@Component
public class DevBootstrap implements ApplicationListener<ContextRefreshedEvent>{
private BookRepository bookRepository;
private AuthorRepository authorRepository;
public DevBootstrap(AuthorRepository authorRepository, BookRepository bookRepository)
{
this.authorRepository = authorRepository;
this.bookRepository = bookRepository;
}
@Override
public void onApplicationEvent(ContextRefreshedEvent contextRefreshedEvent) {
initData();
}
private void initData(){
Author xyz = new Author("xyz","xyz");
Book abc = new Book("Trying to learn Spring","1234","StackOverFlow");
xyz.getBooks().add(abc);
abc.getAuthors().add(xyz);
authorRepository.save(xyz);
bookRepository.save(abc);
}
}
和My Book類：
package com.ex.deneme_1;
import javax.annotation.Generated;
import javax.persistence.*;
import java.util.HashSet;
import java.util.Set;
import java.awt.*;
@Entity
public class Book extends java.awt.print.Book {
@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private String title,isbn,publisher;
private long id;
@ManyToMany
@JoinTable(name = "author_book", joinColumns = @JoinColumn(name="book_id"),
inverseJoinColumns = @JoinColumn(name = "author_id"))
private Set<Author> authors = new HashSet<>();
public Book(){
}
public Book(String title,String isbn, String publisher)
{
this.title = title;
this.isbn = isbn;
this.publisher = publisher;
}
public Book(String title, String isbn, String publisher, Set<Author> author)
{
this.title = title;
this.isbn = isbn;
this.publisher = publisher;
this.authors = author;
}
public String getTitle() { return title; }
public String getIsbn() { return isbn; }
public String getPublisher() { return publisher; }
public Set<Author> getAuthors(){ return authors; }
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
public void setTitle(String title) { this.title = title; }
public void setIsbn(String isbn) { this.isbn = isbn; }
public void setPublisher(String publisher){ this.publisher = publisher; }
public void setAuthors(Set<Author> authors){ this.authors = authors; }
}
我覺得你們很容易猜到我有一個命名爲作者類具有類似於Book.class的功能。
'save'方法不應該是'default
S save（S entity）'?? 'saveAll'方法是一樣的，你應該用'Book'改變'T'' – bracco23是'BookRepository'類或接口？ –
BookRepository是一個接口。 – Zahid