Java 考虑定义EntyMealEngpring Spring启动的bean
我正在使用Spring boot并在以下错误中运行: 组件需要类型为“javax.persistence.EntityManagerFactory”的bean,但找不到该bean 行动: 考虑在配置中定义javax.persistence.EntityManagerFactory类型的bean 我不知道我应该做什么,因为我做每件事都是基于一门课程 我使用@PersistanceUnit来创建EntityManagerFactoryJava 考虑定义EntyMealEngpring Spring启动的bean,java,mysql,spring,hibernate,spring-boot,Java,Mysql,Spring,Hibernate,Spring Boot,我正在使用Spring boot并在以下错误中运行: 组件需要类型为“javax.persistence.EntityManagerFactory”的bean,但找不到该bean 行动: 考虑在配置中定义javax.persistence.EntityManagerFactory类型的bean 我不知道我应该做什么,因为我做每件事都是基于一门课程 我使用@PersistanceUnit来创建EntityManagerFactory <?xml version="1.0"
<?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>2.1.6.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>pl.javastart</groupId>
<artifactId>spring-jpa-boot2</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>spring-jpa-boot2</name>
<description>Spring boot app</description>
<properties>
<java.version>11</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</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>
如何解决这个问题?您的配置在JPA服务器配置和Spring引导之间是固定的 在springboot中,您需要创建一个数据源bean,该bean将由all应用程序使用。通常,您不需要使用EntityManager或EntityManager工厂,这是因为服务器和Spring数据都将创建,您只需要使用Spring创建的存储库和将实现的服务 这是Spring引导应用程序的正常配置
@Configuration
@EnableAutoConfiguration
@ComponentScan(basePackages = {"package.where.are.your.repositorios.and.services"})
@EntityScan(basePackages = "package.where.are.your.entities")
@EnableJpaRepositories(basePackages = "package.where.are.your.repositories", entityManagerFactoryRef = "entityManagerFactory")
@EnableTransactionManagement
public class RepositoryConfiguration {
@Bean
public DataSource jndiDataSource() throws IllegalArgumentException, NamingException {
// Here you can create your datasource using application.properties configuration or inject the datasource from the server application.
JndiObjectFactoryBean bean = new JndiObjectFactoryBean();
bean.setJndiName("JNDI_IN_YOUR_SERVER");
bean.setProxyInterface(DataSource.class);
bean.setLookupOnStartup(true);
bean.afterPropertiesSet();
return (DataSource) bean.getObject();
}
}
这是Spring数据的经典配置,可用于实现存储库
一个存储库示例:
@Repository
public interface BuserRepository extends JpaRepository<Buser, Long> {
@Query("SELECT t FROM Buser t WHERE t.username = :username")
Optional<Buser> findByUsername(@Param("username") String username);
}
@存储库
公共接口BuserRepository扩展了JpaRepository{
@查询(“从Buser t中选择t,其中t.username=:username”)
可选findByUsername(@Param(“用户名”)字符串用户名);
}
如果您想在数据库中保存一些新对象或更新,所有这些都已经在Spring的JpaRepository类中实现,或者还有其他类需要扩展
请在此处阅读更多信息:
我给maven添加了两个依赖项:
<dependency>
<groupId>javax.xml.bind</groupId>
<artifactId>jaxb-api</artifactId>
<version>2.4.0-b180830.0359</version>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-entitymanager</artifactId>
<version>4.3.8.Final</version>
</dependency>
javax.xml.bind
jaxb api
2.4.0-b180830.0359
org.hibernate
休眠实体管理器
4.3.8.最终版本
一切正常您没有Spring Boot应用程序;您没有使用
@EnableAutoConfiguration
或@SpringBootApplication
(其中包含它)。还要注意,您正在重新创建Spring数据;它将自动为您创建整个BookDaoImpl
(请参见crudepository
)。我添加了@SpringBootApplication
,但现在查看org.springframework.beans.factory.BeanCreationException:创建名为“entityManagerFactory”的bean时出错,该bean已在类路径资源中定义[org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaConfiguration.class]:init方法调用失败;嵌套异常为org.hibernate.service.spi.ServiceException:无法创建请求的服务[org.hibernate.engine.jdbc.env.spi.jdbc环境]
您包括了MySQL驱动程序;是否为数据库添加了Spring启动属性?是的,请参见参考资料->应用程序属性Spring.datasource.url=jdbc:mysql://localhost:3306/library?useSSL=false spring.datasource.username=root-spring.datasource.password=admin-spring.jpa.hibernate.ddl auto=create-spring.datasource.tomcat.initial-尺寸=5
@Repository
public interface BuserRepository extends JpaRepository<Buser, Long> {
@Query("SELECT t FROM Buser t WHERE t.username = :username")
Optional<Buser> findByUsername(@Param("username") String username);
}
<dependency>
<groupId>javax.xml.bind</groupId>
<artifactId>jaxb-api</artifactId>
<version>2.4.0-b180830.0359</version>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-entitymanager</artifactId>
<version>4.3.8.Final</version>
</dependency>