Hibernate ServiceImplementation引发NullPointerException

Question

@Entity
@Table(name="apps_departaments")
public class Departament
{
    @Id
    @GeneratedValue
    private int id;

    @Column(name="dep_codi")
    private String CodDep;

    @Column(name="dep_nomc")
    private String nom;

    @Column(name="dep_nomm")
    private String nomCurt;
}

public interface DepartamentDAO
{
    public void afegirDepartament(Departament dep);
    public List<Departament> getDepartaments();
}

departamentdaoimpl.java

@Repository
public class DepartamentDAOImpl implements DepartamentDAO
{
    @Autowired
    private SessionFactory sessionFactory;

    public void afegirDepartament(Departament dep)
    {
        sessionFactory.getCurrentSession().save(dep);
    }

    public List<Departament> getDepartaments()
    {
        return (List<Departament>)(sessionFactory.getCurrentSession().createCriteria(Departament.class).list());
    }
}

departamentservice.java

public interface DepartamentService
{
    public void afegirDepartament(Departament dep);
    public List<Departament> getDepartaments();
}

DepartamentServiceImpl.java

@Service
@Transactional(propagation = Propagation.SUPPORTS, readOnly = true)
public class DepartamentServiceImp implements DepartamentService
{
    @Autowired
    private DepartamentDAO depDAO;

    @Transactional(propagation = Propagation.REQUIRED, readOnly = false)
    @Override
    public void afegirDepartament(Departament dep)
    {
        depDAO.afegirDepartament(dep);
    }

    @Override
    public List<Departament> getDepartaments() {
        return depDAO.getDepartaments();
    }
}

<?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:p="http://www.springframework.org/schema/p"
   xsi:schemaLocation="
       http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
       http://www.springframework.org/schema/context
       http://www.springframework.org/schema/context/spring-context-3.0.xsd">

    <context:component-scan base-package="net.grupgirona.intranet" />
    <context:annotation-config />
    <context:property-placeholder location="classpath*:jdbc.properties"/>
    <import resource="webmvc-config.xml" />
    <import resource="webflow-config.xml" />
    <import resource="data-access-config.xml" />
</beans>

<?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:tx="http://www.springframework.org/schema/tx"
   xmlns:p="http://www.springframework.org/schema/p"
   xsi:schemaLocation="
       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">

<tx:annotation-driven transaction-manager="transactionManager" />
<bean id="dataSource"
    class="org.springframework.jdbc.datasource.DriverManagerDataSource"
    p:driverClassName="${jdbc.driverClassName}"
    p:url="${jdbc.databaseurl}" p:username="${jdbc.username}"
    p:password="${jdbc.password}" />

<bean id="sessionFactory"
    class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">
    <property name="dataSource" ref="dataSource" />
    <property name="configurationClass">
        <value>org.hibernate.cfg.AnnotationConfiguration</value>
    </property>
    <property name="hibernateProperties">
        <props>
            <prop key="hibernate.dialect">${jdbc.dialect}</prop>
            <prop key="hibernate.show_sql">true</prop>
            <prop key="hibernate.hbm2ddl.auto">update</prop>
        </props>
    </property>
    <property name="packagesToScan" value="net.grupgirona.dades"/>
  </bean>

  <bean id="transactionManager"
    class="org.springframework.orm.hibernate3.HibernateTransactionManager">
    <property name="sessionFactory" ref="sessionFactory" />
  </bean>
</beans>

DepartamentServiceImp dades = new DepartamentServiceImp();

Answer 1

你不能用这行

DepartamentServiceImp dades = new DepartamentServiceImp();

因为在DepartamentServiceImp中有一个@Autowired注释状态变量。

Spring不鼓励使用new关键字。您需要的所有实例都必须实例化并从spring上下文中检索。