需要找不到类型为'com.example.demo.bookRepo.BookRepository'的bean

Question

com.example.demo.bookController.BookController中的field bookRepository需要找不到类型为com.example.demo.bookRepo.BookRepository的bean。

注入点具有以下注释：

@org.springframework.beans.factory.annotation.Autowired(required=true)

这是我的Book.java：

@Document(collection = "Book")
public class Book {

    @Id
    private int bookId;
    private String bookName;
    private String bookAuthor;

    public int getBookId() {
        return bookId;
    }

    public Book(int bookId, String bookName, String bookAuthor) {
        super();
        this.bookId = bookId;
        this.bookName = bookName;
        this.bookAuthor = bookAuthor;
    }

    public void setBookId(int bookId) {
        this.bookId = bookId;
    }

    public String getBookName() {
        return bookName;
    }

    public void setBookName(String bookName) {
        this.bookName = bookName;
    }

    public String getBookAuthor() {
        return bookAuthor;
    }

    public void setBookAuthor(String bookAuthor) {
        this.bookAuthor = bookAuthor;
    }

    @Override
    public String toString() {
        return "Book [bookId=" + bookId + ", bookName=" + bookName + ", bookAuthor=" + bookAuthor + "]";
    }

}

BookRepository.java：

@Repository
public interface BookRepository extends MongoRepository<Book, Integer>{

}

这是我的BookController.java：

@RestController
public class BookController {

    @Autowired
    private BookRepository bookRepository;

    @PostMapping("/addBook")
    public String addBook(@RequestBody Book book) {
        bookRepository.save(book);
        return "the boo has been added. ID : " + book.getBookId();
    }

    @GetMapping("/findBook/{id}")
    public Optional<Book> findBookByID(@PathVariable int id) {
        return bookRepository.findById(id);
    }

    @GetMapping("/findBook")
    public List<Book> getAllTheBooks() {
        return bookRepository.findAll();
    }

    @DeleteMapping("/deleteBook")
    public String deleteBook(@PathVariable int id) {
        bookRepository.deleteById(id);
        return "the book with the id : " + id + " is deleted from the DB ";
    }
}

pom.xml：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.4.RELEASE</version>
        <relativePath /> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>restProject-3</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>restProject-3</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-mongodb</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

这是我的文件夹结构：

----com
    ----example
        ----demo
            RestProject3Application.java
            ----bookController
                BookController.java
            ----bookRepo
                BookRepository.java
            ----model
                Book.java

我尝试在主类中添加@EnableMongoRepositories(basePackageClasses = BookRepository.class)，但仍然给我同样的错误。

我还尝试在两个类中添加Qualifier批注，但结果相同。

我还尝试在主类中使用@ComponentScan(basePackages = "com.example.demo.bookRepo, com.example.demo.bookController, com.example.demo")并导致同样的错误。

我无法访问BookRepository bean。有人可以帮我吗？