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问无法在我的java书店应用程序中编辑
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Stack Overflow用户

提问于 2022-02-14 15:09:35

回答 1查看 90关注 0票数 0

我正试图在我的java书店中加入一个编辑功能，但我无法让它开始工作。我很确定我很接近，只是没有正确的逻辑

下面是一些错误代码：

创建名为“bookstoreController”的org.springframework.beans.factory.UnsatisfiedDependencyException:错误:通过字段“存储库”表示的不满意的依赖关系；

导致: org.springframework.data.repository.query.QueryCreationException:无法为公共抽象java.util.List hh.swd20.Bookstore.domain.BookRepository.findOne(java.lang.Long)！创建查询原因:未能为方法公共抽象hh.swd20.Bookstore.domain.BookRepository.findOne(java.lang.Long)！创建查询

由: java.lang.IllegalArgumentException:未能为方法公共抽象java.util.List java.util.List创建查询引起没有找到属性findOne类型的图书！

原因: org.springframework.data.mapping.PropertyReferenceException:没有找到findOne类型的属性！

我不太擅长分析错误，因为我不太清楚它们到底是什么意思。但我知道我的findOne变量有问题。

有很多不同的-java文件和大量di，这是我的代码：

BookstoreController.java

package hh.swd20.Bookstore.web;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;

import hh.swd20.Bookstore.domain.Book;
import hh.swd20.Bookstore.domain.BookRepository;

@Controller
public class BookstoreController {
            @Autowired
            private BookRepository repository;
            
            @RequestMapping("/booklist")
            public String booklist(Model model) {       
                model.addAttribute("books", repository.findAll());
                return "booklist";
            }
            
            @RequestMapping(value = "/add")
            public String addBook(Model model){
                model.addAttribute("book", new Book());
                return "addbook";
            } 
            
            @RequestMapping(value = "/savebook", method = RequestMethod.POST)
            public String save(Book book){
                repository.save(book);
                return "redirect:booklist";
            }
            
            @RequestMapping(value="/books", method = RequestMethod.GET)
            public @ResponseBody List<Book> bookListRest() {
                return (List<Book>) repository.findAll();
            }
            
            @RequestMapping(value="/books/{id}", method = RequestMethod.GET)
            public @ResponseBody Book findbookRest(@PathVariable("id") Long bookId) {
                return (Book) repository.findOne(bookId);
            }
            
            @RequestMapping(value = "/edit/{id}", method = RequestMethod.GET)
            public String editStudent(@PathVariable("id") Long bookId, Model model){
                model.addAttribute("book", repository.findOne(bookId));
                return "editbook";
            }

            @RequestMapping(value = "/delete/{id}", method = RequestMethod.GET)
            public String deleteBook(@PathVariable("id") Long bookId, Model model) {
                repository.deleteById(bookId);
                return "redirect:../booklist";
            }
}

BookRepository.java

package hh.swd20.Bookstore.domain;

import java.util.ArrayList;
import java.util.List;
import org.springframework.data.repository.CrudRepository;

public interface BookRepository extends CrudRepository<Book, Long> {
    
    List<Book> findByTitle(String title);

    List<Book> findOne(Long id);
}

BookstoreApplication.java

package hh.swd20.Bookstore;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;

import hh.swd20.Bookstore.domain.Book;
import hh.swd20.Bookstore.domain.BookRepository;

@SpringBootApplication
public class BookstoreApplication {
    private static final Logger log = LoggerFactory.getLogger(BookstoreApplication.class);

    public static void main(String[] args) {
        SpringApplication.run(BookstoreApplication.class, args);
    }
    
    @Bean
    public CommandLineRunner bookDemo(BookRepository repository) {
        return (args) -> {
            log.info("save a couple of books");
            repository.save(new Book("Shadow of the Conqueror", "Shad M. Brooks", 2019, "945-3-16-14-15", 32));
            repository.save(new Book("The Way of Kings", "Brandon Sanderson", 2010, "9564-17-15-16", 35));  
            
            log.info("fetch all books");
            for (Book book : repository.findAll()) {
                log.info(book.toString());
            }
        };

}
}

Book.java

package hh.swd20.Bookstore.domain;

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

@Entity
public class Book {
    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    private Long id;
    private String title;
    private String author;
    private int year;
    private String isbn;
    private int price;
    
    public Book(String title, String author, int year, String isbn, int price) {
        super();
        this.title = title;
        this.author = author;
        this.year = year;
        this.isbn = isbn;
        this.price = price;
    }
    
    public Book(Long id, String title, String author, int year, String isbn, int price) {
        super();
        this.title = title;
        this.author = author;
        this.year = year;
        this.isbn = isbn;
        this.price = price;
    }
    
    public Book(Long id) {
        super();
        this.id = id;
    }


    public Book() {
    }

    public Long getId() {
        return id;
    }
    
    public String getTitle() {
        return title;
    }

    public String getAuthor() {
        return author;
    }

    public int getYear() {
        return year;
    }

    public String getIsbn() {
        return isbn;
    }

    public int getPrice() {
        return price;
    }
    
    public void setId(Long id) {
        this.id = id;
    }

    public void setTitle(String title) {
        this.title = title;
    }

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

    public void setYear(int year) {
        this.year = year;
    }

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

    public void setPrice(int price) {
        this.price = price;
    }

    @Override
    public String toString() {
        return "Bookstore [id=" + id + ", title=" + title + ", author=" + author + ", year=" + year + ", isbn=" + isbn + ", price="
                + price + "]";
    }
}

booklist.html

<!DOCTYPE HTML>
<html xmlns:th="http://www.thymeleaf.org">
<head>
    <title>Booklist</title>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
</head>
<body>
    <h1>Books</h1>
    <table>
        <tr>
            <th>Title</th>
            <th>Author</th>
        </tr>  
        <tr th:each = "book : ${books}">
            <td th:text="${book.title}"></td>
            <td th:text="${book.author}"></td>      
        <td><a th:href="@{/edit/{id}(id=${book.id})}">Edit</a><a th:href="@{/delete/{id}(id=${book.id})}">Delete</a></td>           
        </tr>
     </table>
     <a href="/add">Add Book</a>
</body>
</html>

addbook.html

<!DOCTYPE HTML>
<html xmlns:th="http://www.thymeleaf.org">
<head>
    <title>Booklist add</title>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
</head>
<body>
    <h1>Add book</h1>
    <div>
        <form th:object="${book}" th:action="@{savebook}" action="#" method="post">
            <label for="booktitle">Title</label>
            <input type="text" id="booktitle" th:field="*{title}" />
            <div style="clear: both; display: block; height: 10px;"></div>
            
            <label for="author">Author</label>
            <input type="text" id="authorname" th:field="*{author}" />
            <div style="clear: both; display: block; height: 10px;"></div>
            
            <label for="bookyear">Year</label>
            <input type="text" th:field="*{year}" />
            <div style="clear: both; display: block; height: 10px;"></div>
            
            <label for="bookisbn">ISBN</label>
            <input type="text" th:field="*{isbn}" />
            <div style="clear: both; display: block; height: 10px;"></div>
            
            <label for="price">Price</label>
            <input type="text" th:field="*{price}" />
            <div style="clear: both; display: block; height: 10px;"></div>
            <input type="submit" value="Save"></input>
        </form>
        <a href="/booklist">Return</a>
    </div>
</body>
</html>

editbook.html

<!DOCTYPE HTML>
<html xmlns:th="http://www.thymeleaf.org">
<head>
    <title>Booklist edit</title>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
</head>
<body>
    <h1>Edit book</h1>
    <div>
        <form th:object="${book}" th:action="@{savebook}" action="#" method="post">
            <label for="booktitle">Title</label>
            <input type="text" id="booktitle" th:field="*{title}" />
            <div style="clear: both; display: block; height: 10px;"></div>
            
            <label for="author">Author</label>
            <input type="text" id="authorname" th:field="*{author}" />
            <div style="clear: both; display: block; height: 10px;"></div>
            
            <label for="bookyear">Year</label>
            <input type="text" th:field="*{year}" />
            <div style="clear: both; display: block; height: 10px;"></div>
            
            <label for="bookisbn">ISBN</label>
            <input type="text" th:field="*{isbn}" />
            <div style="clear: both; display: block; height: 10px;"></div>
            
            <label for="price">Price</label>
            <input type="text" th:field="*{price}" />
            <div style="clear: both; display: block; height: 10px;"></div>
            <input type="submit" value="Save Book"></input>
        </form>
        <a href="/booklist">Return</a>
    </div>
</body>
</html>

java

spring

spring-boot

repository

thymeleaf

回答 1

Stack Overflow用户

发布于 2022-02-14 15:24:36

JPA基于方法名生成查询.findByTitle(字符串t) -> select *其中标题= t；但是findOne(Long id)不能翻译。因此，JPA假设这是一个自定义查询，但是您既不覆盖它，也不通过注释添加自定义查询，所以它失败了。有关更多细节，请参见文档：https://docs.spring.io/spring-data/jpa/docs/current/reference/html/#repositories.query-methods.query-creation。

我建议使用每个CRUD存储库附带的现有函数findById()。

此外，@Kayaman是对的，为什么findOne()函数会返回一个列表。

票数 2

页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持

原文链接：

https://stackoverflow.com/questions/71114003

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