如何創建實體並將其保存到數據庫？

Question

我正在創建一個春季啟動應用程序。 我想將我的testEntity保存在數據庫中。 我在遵循本教程： https : //spring.io/guides/gs/accessing-data-jpa/應該自動創建一個表以保存Entity。

但是，當我嘗試將其作為Spring Booot App運行時，出現以下錯誤：

Error creating bean with name 'demo' defined in backend.Application: Unsatisfied dependency expressed through constructor argument with index 0 of type [test.EntityRepo]: : No qualifying bean of type [test.EntityRepo] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {}; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [test.EntityRepo] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency.

No qualifying bean of type [test.EntityRepo] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {}

請說明我在做什么錯以及如何解決？

您可以在下面找到數據源配置和類。

application.properties：

spring.datasource.url=jdbc:oracle:thin://localhost:1521/orcl
spring.datasource.username=HR
spring.datasource.password=orcl


spring.datasource.driver-class-name=oracle.jdbc.driver.OracleDriver
spring.jpa.hibernate.ddl-auto=create-drop
spring.jpa.properties.hibernate.globally_quoted_identifiers=true
spring.jpa.database-platform=org.hibernate.dialect.Oracle10gDialect
spring.jpa.show-sql=true

testEntity：

package test;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import org.springframework.data.annotation.Id;



@Entity
public class testEntity {

@Id
@GeneratedValue(strategy=GenerationType.AUTO)
private long ID;

private String name;

public testEntity() {}

public testEntity(long iD) {
    ID = iD;
}

public testEntity(String name) {
    this.name = name;
}

public long getID() {
    return ID;
}

public void setID(long iD) {
    ID = iD;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

}

entityRepository：

package test;

import java.util.List;

import org.springframework.data.repository.CrudRepository;
import org.springframework.stereotype.Repository;

@Repository
public interface EntityRepo extends CrudRepository<testEntity, Long>{
List<testEntity> findByName(String name);
}

JPA配置類：

@Configuration
@EnableJpaRepositories
@EnableTransactionManagement
class JpaConfiguration {

  @Bean
  public DataSource dataSource() {

    EmbeddedDatabaseBuilder builder = new EmbeddedDatabaseBuilder();
    return builder.setType(EmbeddedDatabaseType.H2).build();
 }

 @Bean
 public EntityManagerFactory entityManagerFactory() {

    HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
    vendorAdapter.setGenerateDdl(true);

    LocalContainerEntityManagerFactoryBean factory = new LocalContainerEntityManagerFactoryBean();
    factory.setJpaVendorAdapter(vendorAdapter);
    factory.setPackagesToScan("test");
    factory.setDataSource(dataSource());
    factory.afterPropertiesSet();

    return factory.getObject();
  }

  @Bean
  public PlatformTransactionManager transactionManager() { 

    JpaTransactionManager txManager = new JpaTransactionManager();
    txManager.setEntityManagerFactory(entityManagerFactory());
    return txManager;
  }
}

主類：

@EnableSwagger2
@SpringBootApplication
@EnableMapRepositories
public class Application extends WebMvcConfigurerAdapter {

    public static void main(String[] args) {
    SpringApplication.run(Application.class, args);
}



@Bean
public void demo(EntityRepo repository){
    repository.save(new testEntity("jack"));
}

Answer 1

嘗試這個 ：

@Autowired
@Qualifier("demo")
public void demo(EntityRepo repository){
    repository.save(new testEntity("jack"));
}


@Repository("entityRepo")
public interface EntityRepo extends CrudRepository<testEntity, Long>{
List<testEntity> findByName(String name);
}

Answer 2

嘗試這個 ：

@Autowired
public void demo(EntityRepo repository){
    repository.save(new testEntity("jack"));
}

Answer 3

找到了解決方案。 JpaConfig類位於默認程序包中，未指定路徑，將JpaConfig文件移動到帶有Aplication的程序包中可解決此問題