Spring+Hibernate configuration, null SessionFactory

Question

I've been searching extensively for hours, seeing different scenarios with different approaches for a specific/common problem, but having no luck to solve a very simple Null SessionFactory. Here are my classes, I made it as short as possible so while I'm trying to cut down the codes I'm hoping to locate the problem. Still no luck.

The Service Class

public class Service {

  @Autowired
  SessionFactory sessionFactory;

  @Transactional
  public void doSomething() {

     Student stud = new Student();

     stud.setName("Student");
     stud.setAge(23);
     stud.setSchool("School");

     System.out.println(sessionFactory);

     sessionFactory.getCurrentSession().save(stud);
   }
}

My Entity Class (POJO)

@Entity
@Table(name = "STUDENT")
public class Student extends Person {

  @Column(name = "school")
  private String school;

  public Student() {
  }

  public Student(String school) {
     this.school = school;
  }

  public String getSchool() {
    return school;
  }

  public void setSchool(String school) {
    this.school = school;
  }
}

The configuration file (applicationContext.xml)

<?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:aop="http://www.springframework.org/schema/aop"
xmlns:tx="http://www.springframework.org/schema/tx"      xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/aop 
    http://www.springframework.org/schema/aop/spring-aop-4.0.xsd
    http://www.springframework.org/schema/tx 
    http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
    http://www.springframework.org/schema/beans 
    http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
    http://www.springframework.org/schema/context  
    http://www.springframework.org/schema/context/spring-context-4.0.xsd">

<tx:annotation-driven/>

<context:property-placeholder
    location="classpath:properties/database.properties"
    ignore-unresolvable="false" />

<context:component-scan base-package="edu.service"/>

<bean id="dataSource"
    class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    <property name="driverClassName" value="${jdbc.driverClassName}" />
    <property name="url" value="${jdbc.url}" />
    <property name="username" value="${jdbc.username}"/>
    <property name="password" value="${jdbc.password}"/>
</bean>

<bean id="sessionFactory"
    class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
    <property name="dataSource" ref="dataSource"/>
    <property name="hibernateProperties">
        <props>
            <prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop>
            <prop key="hibernate.show_sql">false</prop>
        </props>
    </property>
    <property name="packagesToScan">
        <list>
            <value>edu.domain</value>
        </list>
    </property>
</bean>

<bean id="transactionManager"
    class="org.springframework.orm.hibernate4.HibernateTransactionManager">
    <property name="sessionFactory" ref="sessionFactory" />
</bean>

And the main class

public class MainApp {
   public static void main(String[] args) {
      ApplicationContext context = new ClassPathXmlApplicationContext(
            "/config/applicationContext.xml");

      Service service = new Service();
      service.doSomething();

      ((ClassPathXmlApplicationContext) context).registerShutdownHook();
      ((ClassPathXmlApplicationContext) context).close();
  } 
}

I really dont get why do I have a null SessionFactory, I tried to made it as short as possible, removed some part of the applications(DAOs,Services,Annotations), still no luck. Any help please. Thank you in Advance

Answer 1

The problem lies in new Service() so the object you've created is not managed by Spring. You never called setSessionFactory() and so SessionFactory is of course null, hence an NPE when you try to reference it.

You probably want to be getting an Service managed by the Spring container which means you need to inject it somehow. So try injecting the bean Service and then call service.doSomething();

Answer 2

Try this:

First annotate or configure the service in xml. Then get it from the context like below:

public static void main(String[] args) {
    ApplicationContext context = new ClassPathXmlApplicationContext(
            "/config/applicationContext.xml");

    Service service = (Service) context.getBean("service");
    service.doSomething();

    ((ClassPathXmlApplicationContext) context).registerShutdownHook();
    ((ClassPathXmlApplicationContext) context).close();
}

Let me know if this helps.