如何在spring boot中獲取All表元數據 - JPA - hibernate？

Question

我需要動態獲取我的模式中存在的所有表的 META信息，Meta信息是諸如表，實體，列名等。

我遵循了以下教程

https://vladmihalcea.com/how-to-get-the-entity-mapping-to-database-table-binding-metadata-from-hibernate/

如上面的鏈接所述，我創建了名為MetadataExtractorIntegrator.java的Integrator

package com.test.ttv;
import org.hibernate.boot.Metadata;
import org.hibernate.boot.model.relational.Database;
import org.hibernate.engine.spi.SessionFactoryImplementor;
import org.hibernate.service.spi.SessionFactoryServiceRegistry;

public class MetadataExtractorIntegrator implements org.hibernate.integrator.spi.Integrator {

    public static final MetadataExtractorIntegrator INSTANCE = new MetadataExtractorIntegrator();

    private Database database;

    private Metadata metadata;

    public Database getDatabase() {
        return database;
    }

    public Metadata getMetadata() {
        return metadata;
    }

    @Override
    public void integrate(
            Metadata metadata,
            SessionFactoryImplementor sessionFactory,
            SessionFactoryServiceRegistry serviceRegistry) {

        this.database = metadata.getDatabase();
        this.metadata = metadata;

    }

    @Override
    public void disintegrate(
        SessionFactoryImplementor sessionFactory,
        SessionFactoryServiceRegistry serviceRegistry) {

    }
}

並嘗試通過以下配置在我的應用程序中注冊它

application.yml

jpa:
  properties:
    hibernate.integrator_provider: com.test.ttv.MetadataExtractorIntegrator

我在啟動構建時遇到以下異常

Caused by: java.lang.ClassCastException: java.lang.String cannot be cast to org.hibernate.jpa.boot.spi.IntegratorProvider

更多StackTrace

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaConfiguration.class]: Invocation of init method failed; nested exception is java.lang.ClassCastException: java.lang.String cannot be cast to org.hibernate.jpa.boot.spi.IntegratorProvider
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1710) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:583) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:502) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:312) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:228) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:310) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:200) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1085) ~[spring-context-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:858) ~[spring-context-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549) ~[spring-context-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:140) ~[spring-boot-2.0.0.RELEASE.jar:2.0.0.RELEASE]
        at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:752) [spring-boot-2.0.0.RELEASE.jar:2.0.0.RELEASE]
        at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:388) [spring-boot-2.0.0.RELEASE.jar:2.0.0.RELEASE]
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:327) [spring-boot-2.0.0.RELEASE.jar:2.0.0.RELEASE]
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1246) [spring-boot-2.0.0.RELEASE.jar:2.0.0.RELEASE]
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1234) [spring-boot-2.0.0.RELEASE.jar:2.0.0.RELEASE]
        at testtest(Test.java:31) [main/:na]
Caused by: java.lang.ClassCastException: java.lang.String cannot be cast to org.hibernate.jpa.boot.spi.IntegratorProvider
        at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.buildBootstrapServiceRegistry(EntityManagerFactoryBuilderImpl.java:339) ~[hibernate-core-5.2.14.Final.jar:5.2.14.Final]
        at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.<init>(EntityManagerFactoryBuilderImpl.java:196) ~[hibernate-core-5.2.14.Final.jar:5.2.14.Final]
        at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.<init>(EntityManagerFactoryBuilderImpl.java:164) ~[hibernate-core-5.2.14.Final.jar:5.2.14.Final]
        at org.springframework.orm.jpa.vendor.SpringHibernateJpaPersistenceProvider.createContainerEntityManagerFactory(SpringHibernateJpaPersistenceProvider.java:51) ~[spring-orm-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:365) ~[spring-orm-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:388) ~[spring-orm-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:377) ~[spring-orm-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.afterPropertiesSet(LocalContainerEntityManagerFactoryBean.java:341) ~[spring-orm-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1769) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1706) ~[spring-beans-5.0.4.RELEASE.jar:5.0.4.RELEASE]
        ... 16 common frames omitted

誰能幫我解決這個問題？ 謝謝

Answer 1

在Spring Boot中， spring.jpa.properties指向Map<String, String> ，因此它只能包含String值。

但是在Hibernate中，當EntityManagerFactoryBuilderImpl讀取hibernate.integrator_provider它期望找到IntegratorProvider的實例而不是類名，因此是例外。

但是，您可以添加一個實現HibernatePropertiesCustomizer的bean，以將IntegrationProvider實例添加到Hibernate屬性中：

@Component
public class HibernateConfig implements HibernatePropertiesCustomizer {

    @Override
    public void customize(Map<String, Object> hibernateProperties) {
        hibernateProperties.put("hibernate.integrator_provider",
                (IntegratorProvider) () -> Collections.singletonList(MetadataExtractorIntegrator.INSTANCE));
    }
}

我在這個存儲庫中創建了一個工作示例。

Answer 2

如果您使用的是Springboot 1.5.x，則“HibernatePropertiesCustomizer”不存在。

我從這里找到了一個可用的解決方案 您不能在此處使用集成器，但可以逐個添加所有事件偵聽器。 下面是我的代碼：

public class RootAwareInsertEventListener implements PersistEventListener {

    public static final RootAwareInsertEventListener INSTANCE = new RootAwareInsertEventListener();

    @Override
    public void onPersist(PersistEvent event) throws HibernateException {
        final Object entity = event.getObject();

        if (entity instanceof RootAware) {
            RootAware rootAware = (RootAware) entity;
            Object root = rootAware.getRoot();
            event.getSession().lock(root, LockMode.OPTIMISTIC_FORCE_INCREMENT);

            log.info("Incrementing {} entity version because a {} child entity has been inserted",
                    root, entity);
        }
    }

    @Override
    public void onPersist(PersistEvent event, Map createdAlready)
            throws HibernateException {
        onPersist(event);
    }
}

@Component
public class HibernateListenerConfigurer {

    @PersistenceUnit
    private EntityManagerFactory emf;

    @PostConstruct
    protected void init() {
        SessionFactoryImpl sessionFactory = emf.unwrap(SessionFactoryImpl.class);
        EventListenerRegistry registry = sessionFactory.getServiceRegistry().getService(EventListenerRegistry.class);
        registry.getEventListenerGroup(EventType.PERSIST).appendListener(RootAwareInsertEventListener.INSTANCE);
        registry.getEventListenerGroup(EventType.FLUSH_ENTITY).appendListener(RootAwareUpdateAndDeleteEventListener.INSTANCE);

    }
}

Answer 3

在org.springframework.orm.hibernate5.LocalSessionFactoryBean ， hibernateIntegrators有一個變量參數setter方法，它接受org.hibernate.integrator.spi.Integrator一個或多個實例。

所以在org.springframework.orm.hibernate5.LocalSessionFactoryBean配置中添加以下屬性

<property name="hibernateIntegrators" ref="metadataExtractorIntegrator" />

並將Integrator作為托管bean

    package com.test.ttv;
    import org.hibernate.boot.Metadata;
    import org.hibernate.boot.model.relational.Database;
    import org.hibernate.engine.spi.SessionFactoryImplementor;
    import org.hibernate.service.spi.SessionFactoryServiceRegistry;
    import org.springframework.stereotype.Component;

    @Component  
    public class MetadataExtractorIntegrator implements org.hibernate.integrator.spi.Integrator {

        private Database database;

        private Metadata metadata;

        public Database getDatabase() {
            return database;
        }

        public Metadata getMetadata() {
            return metadata;
        }

        @Override
        public void integrate(
                Metadata metadata,
                SessionFactoryImplementor sessionFactory,
                SessionFactoryServiceRegistry serviceRegistry) {

            this.database = metadata.getDatabase();
            this.metadata = metadata;

        }

        @Override
        public void disintegrate(
            SessionFactoryImplementor sessionFactory,
            SessionFactoryServiceRegistry serviceRegistry) {

        }
    }