NullPointerException in SessionFactory

Question

使用java @Bean注释配置Hibernate

@Configuration
@ComponentScan(basePackages = {"com.worldofshopping.BackendShop"})
@ComponentScan(basePackages = {"com.worldofshopping"})
@EnableTransactionManagement
public class HibernateConfig {
    BasicDataSource dataSource;
    // Change the below final variable value based on database you choose

    private final static String DATABASE_URL = "jdbc:h2:~/rahul";
    private final static String DATABASE_DRIVER = "org.h2.Driver";
    private final static String DATABASE_DIALECTS = "org.hibernate.dialect.H2Dialect";
    private final static String DATABASE_USERNAME = "sa";
    private final static String DATABASE_PASSWORD = "sa";

    // Database will be available
    @Bean("dataSource")
    public DataSource getSource() {
        dataSource = new BasicDataSource();
        // Providing database connection Information
        dataSource.setDriverClassName(DATABASE_DRIVER);
        dataSource.setUrl(DATABASE_URL);
        dataSource.setUsername(DATABASE_USERNAME);
        dataSource.setPassword(DATABASE_PASSWORD);

        return dataSource;
    }

    // Database will be available
    @Autowired
    @Bean
    public SessionFactory getSessionFactory(DataSource datasource) {
        LocalSessionFactoryBuilder builder = new LocalSessionFactoryBuilder(dataSource);
        builder.addProperties(getHibernateProperties());
        builder.scanPackages("com.worldofshopping.BackendShopndShop.dto");
        return builder.buildSessionFactory();
    }

    // For Hibernate property return
    private Properties getHibernateProperties() {
        Properties properties = new Properties();
        properties.put("hibernate.dialect", DATABASE_DIALECTS);
        properties.put("hibernate.show_sql", "true");
        properties.put("hibernate.format_sql", "true");
        properties.put("hibernate.hbm2ddl.auto", "update");

        return properties;
    }

    // HibernateTransactionManager
    @Autowired
    @Bean
    public HibernateTransactionManager getTransactionManagement(SessionFactory sessionFactory) {
        HibernateTransactionManager transactionManager = new HibernateTransactionManager(sessionFactory);
        return transactionManager;
    }
}


@Repository("userDao")
@Transactional
public class Userdaoimpl implements Userdao {

    @Autowired(required = true)
    private SessionFactory sessionFactory;

    @Override
    public User getUserByUsername(String email) {
        String command = "from User where email=:parameter";
        Query<User> query = sessionFactory.getCurrentSession().createQuery(command, User.class);
        query.setParameter("parameter", email);
        try {
            return query.getSingleResult();
        } catch (Exception ex) {
            ex.printStackTrace();
            return null;
        }
    }

    @Override
    public boolean add(User user) {
        try {
            Cart cart = new Cart();
            cart.setUser(user);
            user.setCart(cart);
            sessionFactory.getCurrentSession().save(user);
            return true;
        } catch (Exception msg) {
            msg.printStackTrace();
            System.out.println(msg);
            return false;
        }
    }

    @Override
    public boolean update(User user) {
        try {
            sessionFactory.getCurrentSession().update(user);
            return true;
        } catch (Exception msg) {
            msg.printStackTrace();
            System.out.println("Something error occured during Update " + msg);
            return false;
        }
    }

    @Override
    public boolean delete(String email) {
        User user = getUserByUsername(email);
        user.setEnabled(false);
        try {
            sessionFactory.getCurrentSession().update(user);
            return true;
        } catch (Exception msg) {
            msg.printStackTrace();
            System.out.println("Something error occured during delete");
            return false;
        }
    }

    @Override
    public User getUserById(Long user_id) {

        try {
            return sessionFactory.getCurrentSession().get(User.class, Long.valueOf(user_id));

        } catch (Exception msg) {
            msg.printStackTrace();
            System.out.println("Something error occured during Update");
            return null;
        }
    }

}

主方法：

public class App {

    public static void main(String[] args) {
        User user = new User();
        user.setAddress("New Delhi");
        user.setContact("9988776655");
        user.setEmail("komal@gmail.com");
        user.setEnabled(true);
        user.setName("Komal");
        user.setPassword("komal");
        user.setRole("CUSTOMER");
        Userdao userdao = new Userdaoimpl();
        userdao.add(user);
    }
}

异常堆栈跟踪：

com.worldofshopping.BackendShop.daoimpl.Userdaoimpl.add的java.lang.NullPointerException java.lang.NullPointerException (Userdaoimpl.java:37)在com.worldofshopping.BackendShop.App.main(App.java:25)

任何人请帮助我已经开始使用@Repository("userDao") @Transactional进行事务处理。

我也试着在junit上运行，但仍然有相同的错误！！

Answer 1

您只在您的主要方法中构造了User和Userdaoimpl！扪心自问，SessionFactory和其他@Bean将如何初始化？

尝试通过spring上下文或作为spring引导应用程序运行应用程序。然后获取userdao Bean来调用add方法。