Spring学习（十一）使用对象-关系映射持久化数据

一、spring集成hibernate

• 配置Session·Factory

@Bean
  public SessionFactory sessionFactoryBean() {
    try {
      LocalSessionFactoryBean lsfb = new LocalSessionFactoryBean();
      lsfb.setDataSource(dataSource());
      lsfb.setPackagesToScan("spittr.domain");
      Properties props = new Properties();
      //props.setProperty("dialect", "org.hibernate.dialect.H2Dialect");
      props.setProperty("dialect", "org.hibernate.dialect.MySQL5Dialect");
      lsfb.setHibernateProperties(props);
      lsfb.afterPropertiesSet();
      SessionFactory object = lsfb.getObject();
      return object;
    } catch (IOException e) {
      return null;
    }

• 创建Repository

@Repository
public class HibernateSpitterRepository implements SpitterRepository {

    private SessionFactory sessionFactory;

    @Inject
    public HibernateSpitterRepository(SessionFactory sessionFactory) {
        this.sessionFactory = sessionFactory;        //<co id="co_InjectSessionFactory"/>
    }
    
    private Session currentSession() {
        return sessionFactory.getCurrentSession();//<co id="co_RetrieveCurrentSession"/>
    }
    
    public long count() {
        return findAll().size();
    }

    public Spitter save(Spitter spitter) {
        Serializable id = currentSession().save(spitter);  //<co id="co_UseCurrentSession"/>
        return new Spitter((Long) id, 
                spitter.getUsername(), 
                spitter.getPassword(), 
                spitter.getFullName(), 
                spitter.getEmail(), 
                spitter.isUpdateByEmail());
    }

    public Spitter findOne(long id) {
        return (Spitter) currentSession().get(Spitter.class, id); 
    }

    public Spitter findByUsername(String username) {        
        return (Spitter) currentSession() 
                .createCriteria(Spitter.class) 
                .add(Restrictions.eq("username", username))
                .list().get(0);
    }

    public List<Spitter> findAll() {
        return (List<Spitter>) currentSession() 
                .createCriteria(Spitter.class).list(); 
    }
    
}

二、Spring使用jpa

• 配置容器管理类型的JPA

//声明LocalContainerEntity-ManagerFactoryBean
@Bean
  public LocalContainerEntityManagerFactoryBean emf(DataSource dataSource, JpaVendorAdapter jpaVendorAdapter) {
    LocalContainerEntityManagerFactoryBean emf = new LocalContainerEntityManagerFactoryBean();
    emf.setDataSource(dataSource);
    emf.setPersistenceUnitName("spittr");
    emf.setJpaVendorAdapter(jpaVendorAdapter);
    emf.setPackagesToScan("spittr.domain");
    return emf;
  }
//配置JpaVendorAdapter 
 @Bean
  public JpaVendorAdapter jpaVendorAdapter() {
    HibernateJpaVendorAdapter adapter = new HibernateJpaVendorAdapter();
    adapter.setDatabase(Database.H2);
    adapter.setShowSql(true);
    adapter.setGenerateDdl(false);
    adapter.setDatabasePlatform("org.hibernate.dialect.H2Dialect");
    return adapter;
  }

• 编写Repository

@Repository
public class JpaSpitterRepository implements SpitterRepository {

    @PersistenceContext
    private EntityManager entityManager;

    public long count() {
        return findAll().size();
    }

    public Spitter save(Spitter spitter) {
        entityManager.persist(spitter);
        return spitter;
    }

    public Spitter findOne(long id) {
        return entityManager.find(Spitter.class, id);
    }

    public Spitter findByUsername(String username) {        
        return (Spitter) entityManager.createQuery("select s from Spitter s where s.username=?").setParameter(1, username).getSingleResult();
    }

    public List<Spitter> findAll() {
        return (List<Spitter>) entityManager.createQuery("select s from Spitter s").getResultList();
    }
    
}

三、编写最终版Spring Data JPA Repository

public interface SpitterSweeper {

    int eliteSweep();

}

public interface SpitterRepository extends JpaRepository<Spitter, Long>, SpitterSweeper {
      
    Spitter findByUsername(String username);
    
    List<Spitter> findByUsernameOrFullNameLike(String username, String fullName);

}

public class SpitterRepositoryImpl implements SpitterSweeper {

    @PersistenceContext
    private EntityManager em;
    
    public int eliteSweep() {
      String update = 
          "UPDATE Spitter spitter " +
            "SET spitter.status = 'Elite' " +
            "WHERE spitter.status = 'Newbie' " +
            "AND spitter.id IN (" +
            "SELECT s FROM Spitter s WHERE (" +
            "  SELECT COUNT(spittles) FROM s.spittles spittles) > 10000" +
            ")";
        return em.createQuery(update).executeUpdate();
      }
      public List<Spitter> eliteSweep2() {
        System.out.println("SpitterRepositoryImpl.eliteSweep2()");
        String sec = "select s from Spitter s ";
        List<Spitter> list = em.createQuery(sec).getResultList();
        return list;
    }   
}
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes=JpaConfig.class)
public class SpitterRepositoryTest {
        //测试代码
        @Test
        @Transactional
        public void testA() {
          List<Spitter> list = spitterRepository.eliteSweep2();
          for(Spitter spitter : list)
             System.out.println("username:"+spitter.getUsername());
    }
}