方法抛出'org.hibernate.LazyInitializationException'异常

Question

我在使用LazyInitializationException，createQuery()或load()方法时获得get()。配置基于注释。

这是我得到的例外情况：

Method threw 'org.hibernate.LazyInitializationException' exception. Cannot evaluate lt.package.to.Setting_$$_jvstfff_0.toString()

架构结构：

CREATE TABLE IF NOT EXISTS `Settings` (
  `key` varchar(255) COLLATE utf8_lithuanian_ci NOT NULL,
  `value` varchar(255) COLLATE utf8_lithuanian_ci DEFAULT NULL,
  PRIMARY KEY (`key`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_lithuanian_ci;

persistence config.Java

@Configuration
@ComponentScan(basePackages= {"lt.setkus.sandbox.persistence"})
@EnableTransactionManagement
@PropertySource({"/WEB-INF/properties/configuration.properties"})
public class PersistenceConfig {

    @Autowired
    private Environment environment;

    private Properties getHibernateProperties() {
        Properties properties = new Properties();

        properties.setProperty("hibernate.hbm2ddl.auto", environment.getProperty("hibernate.hbm2ddl.auto"));
        properties.setProperty("hibernate.dialect", environment.getProperty("hibernate.dialect"));
        properties.setProperty("hibernate.globally_quoted_identifiers", "true");

        return properties;
    }

    @Bean
    public LocalSessionFactoryBean provideSessionFactoryBean() {
        LocalSessionFactoryBean localSessionFactoryBean = new LocalSessionFactoryBean();

        localSessionFactoryBean.setDataSource(getDataSource());
        localSessionFactoryBean.setPackagesToScan("lt.setkus.sandbox.persistence.domain");
        localSessionFactoryBean.setHibernateProperties(getHibernateProperties());

        return localSessionFactoryBean;
    }

    @Bean
    public DataSource getDataSource() {
        DriverManagerDataSource dataSource = new DriverManagerDataSource();

        dataSource.setDriverClassName(environment.getProperty("jdbc.driver"));
        dataSource.setUrl(environment.getProperty("jdbc.url"));
        dataSource.setUsername(environment.getProperty("jdbc.user"));
        dataSource.setPassword(environment.getProperty("jdbc.password"));

        return dataSource;
    }

    @Bean
    @Autowired
    public HibernateTransactionManager provideTransactionManager(SessionFactory sessionFactory) {
        HibernateTransactionManager hibernateTransactioManager = new HibernateTransactionManager();
        hibernateTransactioManager.setSessionFactory(sessionFactory);

        return hibernateTransactioManager;
    }

    @Bean
    public PersistenceExceptionTranslationPostProcessor provideExceptionTranslationPostProcessor() {
        return new PersistenceExceptionTranslationPostProcessor();
    }

    @Bean
    public PostItemRepository postItemRepository() {
        return new FacebookPostRepository();
    }

    @Bean
    public PostPersistenceService postPersistenceService(PostItemRepository postItemRepository) {
        return new PostPersistenceEventHandler(postItemRepository);
    }

    @Bean
    public SettingRepository provideSettingRepository() {
        return new SettingDatabaseRepository();
    }

    @Bean
    public SettingPersistenceService provideSettingPersistenceService(SettingRepository settingRepository) {
        return new SettingPersistenceEventHandler(settingRepository);
    }
}

域模型类

@Entity
@Table(name = "settings")
public class Setting implements Serializable {
    @Id
    @Column(name = "key", unique = true)
    private String key;

    @Column(name = "value")
    private String value;

    public String getKey() {
        return key;
    }

    public void setKey(String key) {
        this.key = key;
    }

    public String getValue() {
        return value;
    }

    public void setValue(String value) {
        this.value = value;
    }

    public SettingDetails toSettingDetails() {
        SettingDetails settingDetails = new SettingDetails();
        BeanUtils.copyProperties(this, settingDetails);

        return settingDetails;
    }

    public static Setting fromSettingDetails(SettingDetails settingDetails) {
        Setting setting = new Setting();
        BeanUtils.copyProperties(settingDetails, setting);

        return setting;
    }
}

服务层

public class SettingDatabaseRepository implements SettingRepository {

    @Autowired
    private SessionFactory sessionFactory;

    @Override
    @Transactional
    public Setting get(final String key) {
       return (Setting)sessionFactory.getCurrentSession().get(Setting.class, key);
    }
}

我真的找不到导致这些异常的任何错误。我做错了什么？

Answer 1

通过id获取对象的正确方法是

   public Setting get(final String key) {
      return (Setting)  sessionFactory.getCurrentSession().get(Setting.class, key);
   }