弹簧靴：需要找不到的 'javax.persistence.EntityManagerFactory' 类型的 bean

Question

我正在开发一个Spring Boot应用程序，在启动服务器时遇到了这个错误。我不确定我是否错误地定义了任何注释或缺少任何依赖项。如有任何帮助，我们将不胜感激。

主要类别：

@SpringBootApplication
@Configuration
@ComponentScan
@EnableAutoConfiguration
public class DemoApplication {
public static void main(String[] args) {
System.out.println("Hello world");
SpringApplication.run(DemoApplication.class, args);
}
}

用户服务类别：

@Service
public class UserService implements IUserService {
@Autowired
private UserDAO userDAO;
@Override
public List<UserDTO> getAllUsers() {
List<User> entities = userDAO.getUsers();
List<UserDTO> users = new ArrayList<UserDTO>();//Will never use directly User Object, will be using Tranferable objects
Iterator<User> iterator = entities.iterator();
while(iterator.hasNext()) {
User user = iterator.next();
users.add(ApiDTOBuilder.userToUserDTO(user));//We are building UserDTO object.
}
return users;
}
@Override
public UserDTO getUserByUsername(String username) {
User user = userDAO.getUser(username);
return ApiDTOBuilder.userToUserDTO(user);
}
@Override
public void createUser(UserDTO user) {
userDAO.createUser(ApiDTOBuilder.userDTOToUser(user));
}
@Override
public void updateUser(UserDTO user) {
userDAO.updateUser(ApiDTOBuilder.userDTOToUser(user));
}
@Override
public void deleteUser(String username) {
userDAO.deleteUser(username);
}
}

UserDAO类：

@存储库公共类UserDAO实现IUserDAO｛

@PersistenceContext
EntityManager em;//JPA EntityManager is used to access a database in a particular application. It is used to manage persistent entity instances, to find entities by their primary key identity(As here is Username), and to query over all entities.
@Override
@Transactional
public User getUser(String username) {
return em.find(User.class, username); //Here entitymanager can find the username as it has the capability to find an entity by unique identifies
}

@Override
@Transactional
public List<User> getUsers() {
List<User> resultList = em.createQuery("FROM user_tbl", User.class).getResultList();
return resultList;
}
@Override
@Transactional
public void createUser(User user) {
em.persist(user);//Make an instance managed and persistent.
}
@Override
@Transactional
public void updateUser(User user) {
em.merge(user);//Merge the state of the given entity into the current persistence context.
}
@Override
@Transactional
public void deleteUser(String username) {
User user = this.getUser(username);
em.remove(user);//Remove the entity instance.
}
}

Build.gradle:

buildscript {
ext {
springBootVersion = '2.0.0.RELEASE'
}
repositories {
mavenCentral()
}
dependencies {
classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
}
}
apply plugin: 'java'
apply plugin: 'eclipse'
apply plugin: 'org.springframework.boot'
apply plugin: 'io.spring.dependency-management'
group = 'com.example'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = 1.8
repositories {
mavenCentral()
}

dependencies {
compile('org.springframework.boot:spring-boot-starter-data-jpa')
compile('org.springframework.boot:spring-boot-starter-web')
compile('org.springframework.boot:spring-boot-starter-security')
compile('org.hibernate.javax.persistence:hibernate-jpa-2.1-api:1.0.0.Final')
compile('javax.xml.bind:jaxb-api:2.2.11')
compile('org.springframework.boot:spring-boot-starter-test:2.0.2.RELEASE')
compile('com.sun.xml.bind:jaxb-core:2.2.11')
compile('com.sun.xml.bind:jaxb-impl:2.2.11')
runtime('org.springframework.boot:spring-boot-devtools')
runtime('mysql:mysql-connector-java')
testCompile('org.springframework.boot:spring-boot-starter-test')
}

错误消息：

***************************
APPLICATION FAILED TO START
***************************
Description:
Field userDAO in com.example.demo.service.UserService required a bean of type 'javax.persistence.EntityManagerFactory' that could not be found.
Action:
Consider defining a bean of type 'javax.persistence.EntityManagerFactory' in your configuration.

我看到了所有相关的答案，并尝试实现这些建议，如添加依赖项、在主类中添加注释等。但它显示了相同的错误。请有人帮我。提前谢谢。

第页。S： 我的应用程序的Github链接：https://github.com/heliOpenxCell/demo

Answer 1

我也遇到了同样的问题——你的问题，只要把它添加到你的maven或gradle中，它对我有用！

Maven：

<dependency>
<groupId>org.apache.tomcat</groupId>
<artifactId>tomcat-jdbc</artifactId>
<version>9.0.10</version>
</dependency>

等级：

compile group: 'org.apache.tomcat', name: 'tomcat-jdbc', version: '9.0.10'