Getting NullPointerException in SessionFactory

Question

Hibernate configure using java @Bean annotation

@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;
        }
    }

}

Main method:

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);
    }
}

Exception stack trace:

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

Anyone please help I m already start transaction using @Repository("userDao") @Transactional

I'm also try to run on junit but still get same error!!

score 1 · Answer 1 · answered Jul 19 '17 at 06:08

You have contructed User and Userdaoimpl only in your main method! Question yourself that how the SessionFactory and other @Beans would be initilized?

Try to run the application through spring context or as a spring boot application. Then get userdao Bean to invoke add method.

awagenhoffer · Answer 2 · 2017-07-19T08:13:28.543

You should register your context like that, if you would like to try your app in a JUnit test:

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(loader = AnnotationConfigContextLoader.class,
        classes = { HibernateConfig.class})
public class TestCaseApp {

    @Autowired
    @Qualifier("userDao")
    Userdao userdao;

    @Test
    public void testSessionFactory(){
         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.add(user);
    }
}

You can't use "new" keyword (Userdao userdao = new Userdaoimpl()) on a Spring object. You can register Spring context with spring-boot or if you have a web application, then via the web.xml.

If you would like to use your dao in the main method.

ApplicationContext ctx = new AnnotationConfigApplicationContext(HibernateConfig.class);
Userdao userdao = ctx.getBean("userDao",Userdao.class);

Getting NullPointerException in SessionFactory

2 Answers2