没有找到属性异常org.springframework.beans.factory.UnsatisfiedDependencyException：

Question

这似乎是重复的问题，但我无法找到我正在寻找的答案，而且我的问题略有不同所以请在标记或复制之前耐心等待 -

我有一个保存和删除功能，它使Book Class对象执行插入和删除操作，并且Spring以某种方式将其作为Book类的属性，是否有任何特定的方法来实现 insert 和使用我缺少的CrudRepository时的删除操作，我几乎已经尝试了所有可用的答案但没有帮助，请你指导我解决这个问题。

这是我目前面临的一个例外，下面给出了代码 -

OrderDesctiption = oReader.GetNString(3),

我的实体类

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'booksController': Unsatisfied dependency expressed through field 'bookService'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'bookServiceImpl': Unsatisfied dependency expressed through field 'booksDao'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'booksDao': Invocation of init method failed; nested exception is org.springframework.data.mapping.PropertyReferenceException: No property book found for type Books!

我的DAO界面

package com.nerdbot.lms.model;

import java.sql.Timestamp;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;

@Entity
public class Books {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long buid;
    private String book_Name;
    private String isbn;
    private String author;
    private boolean avialable;
    private String teachers_note;
    private String suid;
    private Timestamp return_date;
    private String meta_tags;
    private boolean award_winner;
    private String subject;
    private boolean banned_in_any_country;
    private String country_of_ban;
    private String aisle;

    public String getIsbn() {
        return isbn;
    }

    public void setIsbn(String isbn) {
        this.isbn = isbn;
    }

    public boolean isAvialable() {
        return avialable;
    }

    public void setAvialable(boolean avialable) {
        this.avialable = avialable;
    }

    public String getMeta_tags() {
        return meta_tags;
    }

    public void setMeta_tags(String meta_tags) {
        this.meta_tags = meta_tags;
    }

    public boolean isAward_winner() {
        return award_winner;
    }

    public void setAward_winner(boolean award_winner) {
        this.award_winner = award_winner;
    }

    public String getSubject() {
        return subject;
    }

    public void setSubject(String subject) {
        this.subject = subject;
    }

    public String getCountry_of_ban() {
        return country_of_ban;
    }

    public void setCountry_of_ban(String country_of_ban) {
        this.country_of_ban = country_of_ban;
    }

    public String getAisle() {
        return aisle;
    }

    public void setAisle(String aisle) {
        this.aisle = aisle;
    }

    public String getSuid() {
        return suid;
    }

    public void setSuid(String suid) {
        this.suid = suid;
    }

    public Long getBuid() {
        return buid;
    }

    public void setBuid(Long buid) {
        this.buid = buid;
    }

    public String getAuthor() {
        return author;
    }

    public void setAuthor(String author) {
        this.author = author;
    }

    public String getBook_Name() {
        return book_Name;
    }

    public void setBook_Name(String book_Name) {
        this.book_Name = book_Name;
    }

    public String getTeachers_note() {
        return teachers_note;
    }

    public void setTeachers_note(String teachers_note) {
        this.teachers_note = teachers_note;
    }

    public Timestamp getReturn_date() {
        return return_date;
    }

    public void setReturn_date(Timestamp return_date) {
        this.return_date = return_date;
    }

    public boolean isBanned_in_any_country() {
        return banned_in_any_country;
    }

    public void setBanned_in_any_country(boolean banned_in_any_country) {
        this.banned_in_any_country = banned_in_any_country;
    }

}

我的服务界面

package com.nerdbot.lms.dao;

import org.springframework.data.repository.CrudRepository;
import org.springframework.stereotype.Repository;

import com.nerdbot.lms.model.Books;

@Repository
public interface BooksDao extends CrudRepository<Books, Long>{

    Iterable<Books> findAll();

    Iterable<Books> findBybuid(int buid);

    Iterable<Books> findByAuthor(String author);

    Iterable<Books> findByMeta_Tags(String meta_tags);

    Iterable<Books> findByBook_Name(String book_Name);

    Iterable<Books> findByIsbn(String isbn);

    Iterable<Books> findBySubject(String subject);


}

我的休息控制器

package com.nerdbot.lms.service;

import com.nerdbot.lms.model.Books;

public interface BookService {

    Iterable<Books> findAll();
    Iterable<Books> findBybuid(int buid);
    Iterable<Books> findByAuthor(String author);
    Iterable<Books> findByMeta_Tags(String meta_tags);
    Iterable<Books> findByBookName(String book_Name);
    Iterable<Books> findByIsbn(String isbn);
    Iterable<Books> findBySubject(String subject);
    void save( Iterable<Books> books);
    void save(Books book);
    void delete(Iterable<Books> books);
    void delete(Books book);

}

完全例外

package com.nerdbot.lms.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.MediaType;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

import com.nerdbot.lms.model.Books;
import com.nerdbot.lms.service.BookService;

@RestController
public class BooksController {

    @Autowired
    BookService bookService;

    @RequestMapping("/getallbooks")
    public  Iterable<Books> getAllBooks(Model model) {

         Iterable<Books> books = bookService.findAll();

        model.addAttribute("books", books);

        return books;
    }

    @RequestMapping(value = "/addbook",headers = {
    "content-type=application/json" }, consumes = MediaType.APPLICATION_JSON_VALUE, method = RequestMethod.POST)
    public void addBook(@RequestBody Books book) {
        bookService.save(book);

    }

    @RequestMapping("/getbyname")
    public  Iterable<Books> getBookByName(@RequestParam(value="bookName", defaultValue="all") String book_Name) {
        return bookService.findByBookName(book_Name);
    }

}

Answer 1

问题在于Repository方法

Iterable<Books> findByBook_Name(String book_Name);

请参阅此link

https://docs.spring.io/spring-data/jpa/docs/current/reference/html/#repositories.query-methods.query-property-expressions

我们应该避免将下划线写为JPA实体中的数据成员，因为_在Spring JPA存储库中具有特殊含义。

JPA认为您在book内有一个名为Books的媒体资源，而您正在追溯到book.name