Question

我将Spring与Hibernate一起使用，并始终为sessionFactory Object提供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();
}

}

我的DAOImpl课程：

@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: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" />

当测试调用insert方法时，我总是从currentSession得到一个NPE。

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


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

Answer 1

使用Spring时首先要理解的是，Spring依赖注入仅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。

在启用Spring的单元测试中，您可以使用@ContextConfiguration配置应用程序上下文，例如，如下所示（适用于Spring 3.1，在先前版本@ContextConfiguration中不直接使用@Configuration类，因此你必须创建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

使用sessionFactory.openSession（），而不是xxxDAOImpl类的currentSession（）函数中的sessionFactory.getCurrentSession（）。

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，因此您需要打开会话。

希望这会对你有所帮助。欢呼声。

Spring + Hibernate + DAO + SessionFactory + Inject

2 个答案: