Java JPA Hibernate Spring @EntityListeners抛出org.springframework.dao.DataIntegrityViolationException

Question

我正在使用Spring 3和Hibernate 3。我想在更新实体时自动更新上次修改日期。以下是示例代码：

HibernateConfig：

@Configuration
public class HibernateConfig {

    @Bean
    public DataSource dataSource() throws Exception {
        DriverManagerDataSource dataSource = new DriverManagerDataSource();
        Properties properties = new Properties();
        properties.load(ClassLoader.getSystemResourceAsStream(new String("hibernate.properties")));
        dataSource.setUrl(properties.getProperty(new String("jdbc.url")));
        dataSource.setUsername(properties.getProperty(new String("jdbc.username")));
        dataSource.setPassword(properties.getProperty(new String("jdbc.password")));
        dataSource.setDriverClassName(properties.getProperty(new String("jdbc.driverClassName")));
        return dataSource;
    }

    @Bean
    public AnnotationSessionFactoryBean sessionFactory() throws Exception {
        AnnotationSessionFactoryBean sessionFactory = new AnnotationSessionFactoryBean();
        Properties hibernateProperties = new Properties();
        Properties properties = new Properties();
        properties.load(ClassLoader.getSystemResourceAsStream(new String("hibernate.properties")));

        // set the Hibernate Properties
        hibernateProperties.setProperty(new String("hibernate.dialect"), properties.getProperty(new String("hibernate.dialect")));
        hibernateProperties.setProperty(new String("hibernate.show_sql"), properties.getProperty(new String("hibernate.show_sql")));
        hibernateProperties.setProperty(new String("hibernate.hbm2ddl.auto"), properties.getProperty(new String("hibernate.hbm2ddl.auto")));
        sessionFactory.setDataSource(dataSource());
        sessionFactory.setHibernateProperties(hibernateProperties);
        sessionFactory.setAnnotatedClasses(new Class[]{Message.class})
        return sessionFactory;
    }

    @Bean
    public HibernateTemplate hibernateTemplate() throws Exception {
        HibernateTemplate hibernateTemplate = new HibernateTemplate();
        hibernateTemplate.setSessionFactory(sessionFactory().getObject());
        return hibernateTemplate;
    }
}

DAOConfig：

@Configuration
public class DAOConfig {

    @Autowired
    private HibernateConfig hibernateConfig;

    @Bean
    public MessageDAO messageDAO() throws Exception {
        MessageDAO messageDAO = new MessageHibernateDAO(hibernateConfig.hibernateTemplate());
        return messageDAO;
    }
}

消息：

import java.util.Date;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.EntityListeners;
import javax.persistence.Table;
import javax.persistence.Temporal;
import javax.persistence.TemporalType;
import java.io.Serializable;
import javax.persistence.Column;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;

@Entity
@Table
@EntityListeners(value = MessageListener.class)
public class Message implements Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column
    private int id;
    @Column(nullable = false)
    @Temporal(TemporalType.TIMESTAMP)
    private Date lastMod;

    public Message() {

    }

    public int getId() {
       return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public Date getLastMod() {
        return lastMod;
    }

    public void setLastMod(Date lastMod) {
        this.lastMod = lastMod;
    }
}

MessageListener：

import java.util.Date;
import javax.persistence.PrePersist;
import javax.persistence.PreUpdate;
import org.springframework.stereotype.Component;

@Component
public class MessageListener {


    @PrePersist
    @PreUpdate
    public void setLastMod(Message message) {
        message.setLastMod(new Date());
    }
}

运行此命令时，不会调用MessageListener。我使用DAO设计模式，当调用dao.update(消息)时，它抛出以下异常：

org.springframework.dao.DataIntegrityViolationException: not-null property references a null or transient value: com.persistence.entities.MessageStatus.lastMod; nested exception is org.hibernate.PropertyValueException: not-null property references a null or transient value: com.persistence.entities.Message.lastMod
at org.springframework.orm.hibernate3.SessionFactoryUtils.convertHibernateAccessException(SessionFactoryUtils.java:665)
at org.springframework.orm.hibernate3.HibernateAccessor.convertHibernateAccessException(HibernateAccessor.java:412)
at org.springframework.orm.hibernate3.HibernateTemplate.doExecute(HibernateTemplate.java:411)
at org.springframework.orm.hibernate3.HibernateTemplate.executeWithNativeSession(HibernateTemplate.java:374)
at org.springframework.orm.hibernate3.HibernateTemplate.save(HibernateTemplate.java:683)
at com.persistence.dao.hibernate.GenericHibernateDAO.save(GenericHibernateDAO.java:38)

在查看了许多网站后，似乎没有一个解决方案。

Answer 1

您似乎没有使用EntityManager，相当简单的Hibernate SessionFactory。另一个答案Hibernate/JPA - Entity listener not being called properly似乎表明，如果不手动设置侦听器，这将无法工作。

Answer 2

为了让JPA侦听器使用SessionFactory处理Hibernate，从而能够使用注释(@PostPersist，@PostUpdate，...)，我必须使用JPAIntegrator类做以下难看的事情。

这是我的Spring bean：

@Autowired
private LocalSessionFactoryBean sessionFactoryBean;

@PostConstruct
public void init() throws ClassNotFoundException {
    SessionFactoryImplementor sessionFactory = (SessionFactoryImplementor) sessionFactoryBean.getObject();
    SessionFactoryServiceRegistry serviceRegistry = (SessionFactoryServiceRegistry)sessionFactory.getServiceRegistry();

    Configuration configuration = sessionFactoryBean.getConfiguration();

    new JpaIntegrator().integrate(configuration, sessionFactory, serviceRegistry);
}

如果只是为了让日期字段保持更新，那么您应该看看JPA @Version annotation。它的主要目的是提供乐观锁定来管理对数据的并发更新。