Spring + Hibernate + DAO + SessionFactory +注入

Question

我在Hibernate中使用Spring，并且始终获得sessionFactory对象的NPE。

我的配置文件：

@Configuration 
public class HibernateConfiguration { 

@Bean 
public AnnotationSessionFactoryBean sessionFactory() { 
    Properties props = new Properties(); 
    props.put("hibernate.dialect", MySQL5InnoDBDialect.class.getName()); 
    props.put("hibernate.format_sql", "true"); 
    props.put("hibernate.connection.driver_class", "com.mysql.jdbc.Driver"); 
    props.put("hibernate.connection.password", "xxx"); 
    props.put("hibernate.connection.url", "jdbc:mysql://localhost/Market"); 
    props.put("hibernate.connection.username", "philipp"); 

    AnnotationSessionFactoryBean bean = new AnnotationSessionFactoryBean(); 
    bean.setAnnotatedClasses(new Class[] { xxx.class, xxx.class, xxx.class }); 
    bean.setHibernateProperties(props); 
    bean.setSchemaUpdate(true); 
    return bean; 
} 





@Bean 
public HibernateTransactionManager transactionManager() { 
    return new HibernateTransactionManager(sessionFactory().getObject()); 
} 

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

}

我DAOImpl类：

@Repository("xxx") 
public class xxxDAOImpl implements xxxDAO { 

private SessionFactory sessionFactory; 

@Autowired 
public void setSessionFactory(SessionFactory sessionFactory) { 
    this.sessionFactory = sessionFactory; 
} 

private Session currentSession() { 
    return sessionFactory.getCurrentSession(); 
} 
... 

测试用例：

@ContextConfiguration 
@RunWith(SpringJUnit4ClassRunner.class) 
public class TestxxxDAOImpl { 

@Test 
@Transactional 
public void testInsertxxx() throws Exception { 

    xxxDAO xxxDAO = new xxxDAOImpl(); 
    xyz xyz = new xyz(); 
    xxxDAO.insert(xyz); 
    assertNotNull(xyz.getId()); 
    } 

}

APP-context.xml中

<?xml version="1.0" encoding="UTF-8"?> 
<beans xmlns="http://www.springframework.org/schema/beans" 
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  xmlns:context="http://www.springframework.org/schema/context" 
xmlns:tx="http://www.springframework.org/schema/tx" xmlns:jdbc="http://www.springframework.org/schema/jdbc" 
xsi:schemaLocation=" 
    http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.0.xsd 
    http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd 
    http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd 
    http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd"> 


<tx:annotation-driven transaction-manager="transactionManager" /> 
<context:component-scan base-package="xxx.config" /> 
<context:component-scan base-package="xxx.dao" /> 
<context:annotation-config></context:annotation-config> 

测试context.xml的

<?xml version="1.0" encoding="UTF-8"?> 
<beans xmlns="http://www.springframework.org/schema/beans" 
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:jdbc="http://www.springframework.org/schema/jdbc" 
xsi:schemaLocation="http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.0.xsd 
    http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd"> 

<import resource="classpath:/META-INF/spring/app-context.xml" /> 

我得到的总是当测试调用insert方法的currentSession的NPE。

public void insert(xxx xxx) { 
    currentSession().save(xxx); 
} 


private Session currentSession() { 
    return sessionFactory.getCurrentSession(); 
} 

Answer 1

使用Spring时首先要了解的是Spring依赖注入只适用于从应用程序上下文获取的bean，而不适用于使用new创建的bean。 （例如，在Spring 3.1中工作，在以前的版本中，@ContextConfiguration不直接采用@Configuration类，因此您必须创建XML配置文件）：

@Configuration 
public class HibernateConfiguration { 
    // Add your DAO to application context 
    @Bean 
    public xxxDAO xxxDAO() { 
     return new xxxDAOImpl(); 
    } 
    ... 
} 

// Configure application context using the given @Configuration class 
@ContextConfiguration(classes = HibernateConfiguration.class) 
@RunWith(SpringJUnit4ClassRunner.class) 
public class TestxxxDAOImpl { 
    // Obtain DAO from the application context  
    @Autowired xxxDao xxxDao; 
    ... 
} 

Answer 2

相反（）sessionFactory.getCurrentSession（）在currentSession xxxDAOImpl类的功能的，使用sessionFactory.openSession（）。

由于在您的第一次通话中会话工厂中不会有任何当前会话，所以您需要打开会话。

希望这可以帮助你。干杯。