com.car.services.CarServices 中的字段 dao 需要找不到类型为“javax.persistence.EntityManagerFactory”的 bean

Question

正在尝试学习spring-boot基础应用，无法解决这个错误

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应用程序启动失败

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描述：

com.car.services.CarServices 中的字段 dao 需要找不到类型为“javax.persistence.EntityManagerFactory”的 bean。

注入点有如下注解： - @org.springframework.beans.factory.annotation.Autowired(required=true)

动作：

考虑在您的配置中定义类型为“javax.persistence.EntityManagerFactory”的 bean。

存储库文件

@SuppressWarnings("unused")
@Transactional
@Repository
public class CarDAO implements ICarDAO {
    
    @PersistenceContext
    private EntityManager entityManager;

    @SuppressWarnings("unchecked")
    @Override
    public List<Car> getCars() {
        //String hql = "FROM Car ";
        String hql = "FROM Car as a ORDER BY a.id DESC";
        return (List<Car>) entityManager.createQuery(hql).getResultList();
    }

    @Override
    public Car getCar(int carId) {
        return entityManager.find(Car.class, carId);
    }

}

我的 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 https://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>2.7.8</version>
        <relativePath /> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.car</groupId>
    <artifactId>car</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>car-demo</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-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>javax.persistence</groupId>
            <artifactId>javax.persistence-api</artifactId>
            <version>2.2</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
            <version>2.7.8</version>
        </dependency>
        <dependency>
            <groupId>com.mysql</groupId>
            <artifactId>mysql-connector-j</artifactId>
            <version>8.0.32</version>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

服务档案

@Service
public class CarServices implements ICarServices {
    
    @Autowired
    private ICarDAO dao;

    @Override
    public List<Car> getCars() {
        return dao.getCars();
    }

    @Override
    public Car getCars(int carId) {
        return dao.getCar(carId);
    }
    

}

控制器文件

@RestController
@RequestMapping("carservice")
public class CarController {
    
    
    @Autowired
    private ICarServices service;
    
    @GetMapping("car")
    public ResponseEntity<List<Car>> getCars(){
        
        List<Car> cars = service.getCars();
        return new ResponseEntity<List<Car>>(cars, HttpStatus.OK);
        
    }

}

主要功能

@SpringBootApplication(exclude = {DataSourceAutoConfiguration.class})
public class CarDemoApplication {

    public static void main(String[] args) {
        SpringApplication.run(CarDemoApplication.class, args);
        System.out.println("hello from car");
    }

}

我试过了 导入 org.springframework.beans.factory.annotation.Autowired； 在我的 repository.java 文件中，但它对我不起作用。