Spring boot Hibernate数据源异常应用程序启动时出现null异常

Question

得到

错误[SpringApplication]应用程序启动失败org.springframework.beans.factory.BeanCreationException：创建名称为myEntityManagerFactory的bean错误定义在类路径资源[com/员工/服务/配置/DBConfiguration.class]：调用init方法失败；嵌套异常是java.lang.NullPointerException在org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean

原因：java。组织中的lang.NullPointerException。冬眠靴子模型来源内部的hbm。ModelBinder$AbstractPluralAttributeSecondPass。bindCollectionElement（ModelBinder.java:3554）~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]位于org。冬眠靴子模型来源内部的hbm。ModelBinder$AbstractPluralAttributeSecondPass。doSecondPass（ModelBinder.java:3133）~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]位于org。冬眠靴子内部的InFlightMetadataCollectorImpl。processSecondPasses（InFlightMetadataCollectorImpl.java:1696）~（hibernate-core-5.3.7.Final.jar:5.3.7.Final）位于org。冬眠靴子内部的InFlightMetadataCollectorImpl。processSecondPasses（InFlightMetadataCollectorImpl.java:1664）~（hibernate-core-5.3.7.Final.jar:5.3.7.Final）位于org。冬眠靴子模型过程spi。MetadataBuildingProcess。在org上完成（MetadataBuildingProcess.java:287）~[hibernate-core-5.3.7.Final.jar:5.3.7.Final]。冬眠jpa。靴子内部的EntityManagerFactoryBuilderImpl。元数据（EntityManagerFactoryBuilderImpl.java:904）~（hibernate-core-5.3.7.Final.jar:5.3.7.Final）位于org。冬眠jpa。靴子内部的EntityManagerFactoryBuilderImpl。在org上构建（EntityManagerFactoryBuilderImpl.java:935）~（hibernate-core-5.3.7.Final.jar:5.3.7.Final）。springframework。orm。jpa。小贩SpringHibernateJpaPersistenceProvider。createContainerEntityManagerFactory（SpringHibernateJpaPersistenceProvider.java:60）

对于代码

@ConfigurationProperties(prefix = "spring.datasource.employees")
@Bean
public DataSource myDataSource() {
    return DataSourceBuilder.create().build();
}

@Bean
public LocalContainerEntityManagerFactoryBean myEntityManagerFactory() {
    LocalContainerEntityManagerFactoryBean employees = createEntityManagerFactory(
        myDataSource(), "Employees",
        MyMapping.MAPPINGS);
    return employees;
}

@Bean
public EntityManager myEntityManager(@Qualifier("myEntityManagerFactory")
    EntityManagerFactory emf) {
    return entityManager(emf);
}

@Bean
public JpaTransactionManager myTransactionManager(@Qualifier("myEntityManagerFactory")
    EntityManagerFactory emf) {
    return transactionManager(emf);
}

@Bean
public TransactionHelper myTransactionHelper(
    @Qualifier("myTransactionManager")
        JpaTransactionManager transactionManager) {
    TransactionHelper transactionHelper = new TransactionHelper();
    transactionHelper.setPlatformTransactionManager(transactionManager);
    return transactionHelper;
}

// Common methods
private LocalContainerEntityManagerFactoryBean createEntityManagerFactory(
    DataSource dataSource, String persistenceUnitName, String[] mappings) {
    MyLocalContainerEntityManagerFactoryBean entityManagerFactory
        = new MyLocalContainerEntityManagerFactoryBean();
    entityManagerFactory.setDataSource(dataSource);
    entityManagerFactory.setPersistenceUnitName(persistenceUnitName);
    entityManagerFactory.setPackagesToScan("com.employees.domain");
    JpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
    entityManagerFactory.setJpaVendorAdapter(vendorAdapter);
    entityManagerFactory.setJpaProperties(additionalProperties());

    if (mappings != null) {
        entityManagerFactory.setMappingResources(mappings);
    }
    return entityManagerFactory;
}

private JpaTransactionManager transactionManager(EntityManagerFactory emf) {
    JpaTransactionManager transactionManager = new JpaTransactionManager();
    transactionManager.setEntityManagerFactory(emf);
    return transactionManager;
}

private EntityManager entityManager(EntityManagerFactory emf) {
    return SharedEntityManagerCreator.createSharedEntityManager(emf);
}

@Bean
@Primary
public PersistenceExceptionTranslationPostProcessor exceptionTranslation() {
    return new PersistenceExceptionTranslationPostProcessor();
}

private Properties additionalProperties() {
    Properties properties = new Properties();
    properties.setProperty("hibernate.hbm2ddl.auto", "none");
    //        properties.setProperty("hibernate.show_sql", "true");
    properties.setProperty("hibernate.implicit_naming_strategy",
        "com.employees.domain.hibernate.BackwardsCompatibleImplicitNamingStrategy");
    properties.setProperty("hibernate.dialect", "org.hibernate.dialect.MySQLInnoDBDialect");
    return properties;
}

@Bean public TraceProperties traceProperties() {
    TraceProperties traceProperties = new TraceProperties();
    Set<TraceProperties.Include> includes = new HashSet<>();
    includes.addAll(Arrays.asList(TraceProperties.Include.values()));
    traceProperties.setInclude(includes);
    return traceProperties;
}

Answer 1

在我的例子中，这个问题与Hibernate映射有关。有一个. hbm文件中有一个嵌套表或创建数据库连接实体管理器工厂时未定义的关联。