为什么实体管理器在spring boot test父级中不为空，而在存储库中为空？

Question

I've got the entity manager in the parent test class

@RunWith(SpringRunner.class)
@SpringBootTest(
    properties = {
            "spring.profiles.active=test",
            "spring.config.name=app-test"})
public abstract class ViewerTestBase extends DbBuilderImpl {

@Autowired EntityManager em;

The entity manager here is OK. DbBuilder sets up test data. In the @repository it is null

@Repository public class PaymentTransactionDao {
@Autowired EntityManager em;

Causing the test case to fail.

The entity manager is mapped to the h2 database for tests.

The persistence config class is boiler plate

@Configration
@EnableTransactionManagement
public class PersistenceConfig {

  @Bean
  public LocalContainerEntityManagerFactoryBean entityManagerFactory(EntityManagerFactoryBuilder builder) {
    LocalContainerEntityManagerFactoryBean em = builder.dataSource(viewerDataSource())
            .packages("viewer.model")
            .persistenceUnit("viewer")
            .build();
    return em;
  }

  @Bean
  public PlatformTransactionManager transactionManager(
        EntityManagerFactory viewerEntityManagerFactory) {
    return new JpaTransactionManager(pspEntityManagerFactory);
  }

  @Bean
  @Primary
  @ConfigurationProperties(prefix = "viewer.dbo.datasource")
  public DataSource viewerDataSource() {
    return DataSourceBuilder.create().build();
  }

  @Bean
  @ConfigurationProperties(prefix = "viewer.auth.datasource")
  public DataSource authDataSource() {
    return DataSourceBuilder.create().build();
  }

Setup with spring boot starter jpa

compile group: 'org.springframework.boot', name: 'spring-boot-starter-web'
compile("org.springframework.boot:spring-boot-devtools")
compile group: 'org.springframework.boot', name: 'spring-boot-starter-data-jpa'

testCompile group: 'junit', name: 'junit', version: '4.12'
testCompile group: 'com.h2database', name: 'h2'
testCompile('org.springframework.boot:spring-boot-starter-test')
testCompile group: 'org.springframework.boot', name: 'spring-boot-test'
testCompile group: 'org.springframework.boot', name: 'spring-boot-test-autoconfigure'

Answer 1

In order to put EntityManager within persistence context, change:

@Autowired  
private EntityManager entityManager;

To

@PersistenceContext
private EntityManager entityManager;

A persistence context is a set of entity instances in which for any persistent entity identity there is a unique entity instance. Within the persistence context, the entity instances and their lifecycle is managed by a particular entity manager. The scope of this context can either be the transaction, or an extended unit of work.

Official documentation hibernate definitions

Answer 2

Solved this through the use of constructor injection.

Change @Repository constructor

public class ViewItemDao {
  @PersistenceContext
  protected EntityManager em;
  public ViewItemDao(EntityManager em) {
    this.em = em;
  }

Change test. Note that the entity manager was being injected into the test classes with just @RunWith(SpringRunner.class) and @SpringBootTest

@Test
public void testQueryId() throws InvalidSearchParameterException, SearchFailureException {
    generateTransaction("639051cc-4b19-4383-9c9a-89a80cd2a2f9");

    ViewItemDao viewItemDao = new ViewItemDao(em);

I did change @Autowired to @PersistenceContext without noticing a difference.