entitymanager is null on DAO class - spring

Question

I am trying to implement Spring MVC 3 +EclipseLink JPA 2
When I call saveUser for example it returns that
NullPointerException, EntityManager is
null
:
public class UserDAO {
#PersistenceContext
private EntityManager em;
public void setEntityManager(EntityManager em) {
this.em = em;
}
#Transactional
public User saveUser(User user){
return em.merge(user);
}
My config is:
<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
<property name="entityManagerFactory" ref="entityManagerFactory" />
<property name="dataSource" ref="dataSource"></property>
</bean>
<bean id="entityManagerFactory"
class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
<property name="dataSource" ref="dataSource" />
<property name="persistenceUnitName" value="application" />
<property name="jpaVendorAdapter">
<bean
class="org.springframework.orm.jpa.vendor.EclipseLinkJpaVendorAdapter">
<property name="showSql" value="true" />
<property name="databasePlatform" value="org.eclipse.persistence.platform.database.MySQLPlatform" />
<property name="generateDdl" value="false" />
</bean>
</property>
<property name="loadTimeWeaver">
<bean
class="org.springframework.instrument.classloading.SimpleLoadTimeWeaver" />
</property>
</bean>
<bean id="dataSource"
class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="username" value=".." />
<property name="password" value=".." />
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url"
value="jdbc:mysql://..." />
</bean>
Also have
<context:component-scan base-package="com.elasticbeanstalk.mypackage" />
<context:annotation-config />
It does initialize JPA during Tomcat startup. Why am I see NPE? Could I miss something?

Answer 1

If you instantiate the UserDAO manually, nothing will be injected by Spring. If the DAO is in a package which is under your base-package of <context:component-scan ../> then you can simply autowire it into your Controller. If not, either modify the base-package or also you can define the DAO in the appcontext manually, then you can autowire as well.