Question

我的组合是Spring Boot + Spring Data Jpa +多个数据库。我在启动应用程序时遇到NullPointer异常。像SPring Data with Boot这样的感觉无法生成JPA元数据。我没有得到任何与此错误相关的资源。

＆＃13;

Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'jpaMappingContext': Invocation of init method failed; nested exception is java.lang.NullPointerException
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1574)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:539)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:476)
        at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:303)
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
        at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:299)
        at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194)
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:736)
        at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:757)
        at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:480)
        at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:118)
        at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:686)
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:320)
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:957)
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:946)
        at com.verient.infinipay.staticcard.Application.main(Application.java:25)
        ... 6 more
Caused by: java.lang.NullPointerException
        at org.springframework.data.jpa.repository.config.JpaMetamodelMappingContextFactoryBean.getMetamodels(JpaMetamodelMappingContextFactoryBean.java:90)
        at org.springframework.data.jpa.repository.config.JpaMetamodelMappingContextFactoryBean.createInstance(JpaMetamodelMappingContextFactoryBean.java:56)
        at org.springframework.data.jpa.repository.config.JpaMetamodelMappingContextFactoryBean.createInstance(JpaMetamodelMappingContextFactoryBean.java:26)
        at org.springframework.beans.factory.config.AbstractFactoryBean.afterPropertiesSet(AbstractFactoryBean.java:134)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1633)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1570)
        ... 21 more

＆＃13;

我的代码是：

＆＃13;

    public EntityManagerFactory apEntityManagerFactory(
            EntityManagerFactoryBuilder builder) {
        return builder
                .dataSource(apDataSource())
                .packages(Entity1.class, Entity2.class)
                .persistenceUnit("ap-persistent-unit")
                .build()
                .getObject();
    }

    @Bean
    public EntityManagerFactory trEntityManagerFactory(
            EntityManagerFactoryBuilder builder) {
        return builder
                .dataSource(trDataSource())
                .packages(Entity3.class, Entity4.class)
                .persistenceUnit("tr-persistent-unit")
                .build()
                .getObject();
    }

    @Bean
    JpaTransactionManager apTransactionManager(@Qualifier("apEntityManagerFactory") EntityManagerFactory entityManagerFactory) {
        JpaTransactionManager transactionManager = new JpaTransactionManager();
        transactionManager.setEntityManagerFactory(entityManagerFactory);
        return transactionManager;
    }

    @Bean
    JpaTransactionManager trTransactionManager(@Qualifier("trEntityManagerFactory") EntityManagerFactory entityManagerFactory) {
        JpaTransactionManager transactionManager = new JpaTransactionManager();
        transactionManager.setEntityManagerFactory(entityManagerFactory);
        return transactionManager;
    }

＆＃13;

我在application.properties中也有以下hibernate属性。

＆＃13;

spring.jpa.hibernate.ddl-auto: update
spring.jpa.hibernate.naming_strategy: org.hibernate.cfg.ImprovedNamingStrategy
spring.jpa.database: H2
spring.jpa.show-sql: true

＆＃13;

Answer 1

Spring引导默认为classpath上的数据源启用了AutoConfiguration类。您应该明确排除AutoConfiguration类以禁用。

示例：

@EnableAutoConfiguration(exclude = {JndiConnectionFactoryAutoConfiguration.class,DataSourceAutoConfiguration.class,
                                    HibernateJpaAutoConfiguration.class,JpaRepositoriesAutoConfiguration.class,DataSourceTransactionManagerAutoConfiguration.class})
@ComponentScan
public class MyBootApplication {
    public static void main(String[] args) {
        SpringApplication.run(MyBootApplication.class, args);
    }
}

Answer 2

对我来说，结果是由于我用于将JSON类型映射到Java对象的org.hibernate.usertype.UserType的自定义实现。

在我的特定情况下，它映射到java.util.Map，而change in Spring Data JPA导致升级到该版本时出现回归。

修复方法是明确设置地图的通用类型 - 例如Map<String, Object>就我而言。

Answer 3

非常感谢Vishal的想法。就我而言，javax.persistence.AttributeConverter的无通用实现引发了这种异常。更改 class MapConverter implements AttributeConverter<Map, String> { ... }到class MapConverter implements AttributeConverter<Map<String, Object>, String> { ... }确实有帮助。

Answer 4

我遇到了OnetoOne关系中的映射问题。

我的应用具有以下OneToOne关系。

A ||---|| B

B ||---|| C

Since its OnetoOne, I kept entity B primary key same as entity A, using @MapsId as mentioned here 

https://vladmihalcea.com/the-best-way-to-map-a-onetoone-relationship-with-jpa-and-hibernate/

Similarly I kept entity C primary key same as entity B.

我通过更改这种关系来解决此问题

A ||---|| B

A ||---|| C

Spring Boot：创建名为＆＃39; jpaMappingContext＆＃39;：java.lang.NullPointerException的bean时出错

4 个答案: