Spring Boot`org.springframework.beans.factory.BeanCreationException：创建自动装配依赖的bean注入失败；

Question

我是 Spring Boot 新手，我有一个简单的应用程序，它有一个控制器和一个 Thymeleaf 模板。

当应用程序启动时，为了查看是否一切正常，应该运行一个名为 RepoTester 的 Spring ApplicationListener 来检查服务类的方法。服务类调用PersonRepository 的方法，它只是扩展了Spring 的CrudRepository。但是每次我去尝试运行应用程序时，它都会给我消息：

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'repoTester': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private webapps.city2016.micro.code.service.PersonService webapps.city2016.micro.code.bootstrap.RepoTester.personService; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'personService': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private webapps.city2016.micro.code.repo.PersonRepository webapps.city2016.micro.code.service.PersonServiceImpl.personRepository; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [webapps.city2016.micro.code.repo.PersonRepository] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}

但我不明白为什么。

ApplicationListener 类很简单：

@Component
public class RepoTester implements ApplicationListener<ContextRefreshedEvent> {

@Autowired
private PersonService personService;

private static final Logger logger = Logger.getLogger(RepoTester.class);   

@Override
public void onApplicationEvent(ContextRefreshedEvent event) {
    logger.info(RepoTester.class.getName() + ".onApplicationEvent() method called."); 

    // Create Person.
    Person person = new Person();
    person.setName("Cleo Markham");
    person.setAddress("48 Alysbury Road");
    person.setTelephone("34561287");
    person.setEmail("c.laithwaite@collosus.net");
    person = personService.save(person);        

Person 类很简单：

public class Person {

    // Attributes.    
    private Integer personId;
    private String name;
    private String address;
    private String telephone;
    private String email;

每个属性都有getter 和setter 方法。

该应用程序还有一个名为 application.properties 的属性文件，指定要使用的 Derby 数据库：

spring.datasource.driverClassName=org.apache.derby.jdbc.ClientDriver
spring.datasource.url=jdbc:derby://localhost:1527/Library
spring.datasource.username=username
spring.datasource.password=password

服务类的代码很简单：

@Service()
public class PersonServiceImpl implements PersonService {

    @Autowired
    private PersonRepository personRepository;

    private static final Logger logger = Logger.getLogger(PersonServiceImpl.class);   

    public PersonServiceImpl() {
    }

    @Override
    public void delete(Integer personId) {
        logger.info(PersonServiceImpl.class.getName() + ".delete() method called."); 

        personRepository.delete(personId);
    }

    @Override
    public boolean exists(Integer personId) {
        logger.info(PersonServiceImpl.class.getName() + ".exists() method called."); 

        return personRepository.exists(personId);
    }

    @Override
    public Person findOne(Integer personId) {
        logger.info(PersonServiceImpl.class.getName() + ".findOne() method called."); 

        return personRepository.findOne(personId);
    }

    @Override
    public Iterable<Person> findAll() {
        logger.info(PersonServiceImpl.class.getName() + ".findAll() method called."); 

        return personRepository.findAll();
    }

    @Override
    public Person save(Person person) {
        logger.info(PersonServiceImpl.class.getName() + ".save() method called."); 

        return personRepository.save(person);
    }    

而存储库是：

package webapps.city2016.micro.code.repo;

import org.springframework.data.repository.CrudRepository;

import webapps.city2016.micro.code.model.Person;

public interface PersonRepository extends CrudRepository<Person, Integer> {
} 

我的 Maven 文件是：

http://maven.apache.org/xsd/maven-4.0.0.xsd"> 4.0.0 webapps.city2016.micro 注册SpringBootThymeleaf1 1.0-快照 罐子
UTF-8 1.8 1.8

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.3.5.RELEASE</version>
    <relativePath />
</parent>

<dependencies>
    <dependency>
        <groupId>org.apache.derby</groupId>
        <artifactId>derbyclient</artifactId>
        <version>10.12.1.1</version>
    </dependency>      
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-jdbc</artifactId>
    </dependency>  
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</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</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-thymeleaf</artifactId>
    </dependency>                    
</dependencies>

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

<name>RegistrationSpringBootThymeleaf1</name>

谁能告诉我哪里错了？

Answer 1

我尝试了发布的两个答案，但均未成功，因此应用程序已通过手动编写的 DAO 类转换为 Spring JDBC，并且运行良好。

欢迎任何有关 JPA 的建议。

Answer 2

你需要用JPA注解来注解Person：

@Entity
@Table(name = "person")
public class Person {

    // Attributes.    
    private Integer personId;
    private String name;
    private String address;
    private String telephone;
    private String email;

    @Id
    @Column(name = "id")
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    public Integer getPersonId() { ... }

    @Basic
    @Column(name = "name")
    public String getName() { ... }

Answer 3

您可以在此处阅读所有要求： http://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#boot-features-jpa-and-spring-data

或者检查您是否已完成本教程中提到的所有操作： http://spring.io/guides/gs/accessing-data-jpa/

特别检查您是否拥有：

• 用@SpringBootApplication注释的主类
• 用@Entity注解的实体类
• 用@Id 注释的实体上的主键，并且类型与您的存储库的泛型类型匹配（整数）。
• 您的实体和存储库类位于主类的包级别或以下。