rest webservice - DAO layer and webservice integration, sessionfactory null exception - web-services

Question

We develop a project in mvc with Java. we want to add a rest web service to our project, but when we want to access DAO layer we get sessionFactory is null exception.
How can we inject DAO over web service ?
You can see the code below
Web.java - web service code
package tr.com.server.webservice;
import java.util.ArrayList;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.transaction.annotation.Transactional;
import tr.com.server.model.Admin;
import tr.com.server.persistance.admin.AdminDAO;
#Path("/rota")
public class Web{
#Autowired
#GET
#Produces(MediaType.TEXT_PLAIN)
#Path("/add")
#Transactional
public String adminadd() throws Exception{
Admin m = new Admin();
m.setAdminname("John");
m.setAdminpass("123456");
AdminDAO a = new AdminDAO();
a.add(m);
return "added";
}
}
AdminDAO.java - DAO class
package tr.com.server.persistance.admin;
import java.util.List;
import org.hibernate.Criteria;
import org.hibernate.SessionFactory;
import org.hibernate.criterion.Order;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;
import org.springframework.transaction.annotation.Transactional;
import tr.com.server.model.Admin;
#Repository
public class AdminDAO implements IAdminDAO {
#Autowired
private SessionFactory sessionFactory;
public SessionFactory getSessionFactory() {
return sessionFactory;
}
#Autowired
public void setSessionFactory(SessionFactory sessionFactory) {
this.sessionFactory = sessionFactory;
}
#Autowired
#Transactional
#Override
public Admin add(Admin entity) throws Exception {
try {
getSessionFactory().getCurrentSession().save(entity);
getSessionFactory().getCurrentSession().flush();
getSessionFactory().getCurrentSession().refresh(entity);
return entity;
} catch (RuntimeException e) {
throw new Exception(e);
}
}
}
iAdminDAO.java - AdminDAO interface
package tr.com.server.persistance.admin;
import java.util.List;
import org.springframework.transaction.annotation.Transactional;
import tr.com.server.model.Admin;
#Transactional
public interface IAdminDAO {
Admin add(Admin entity) throws Exception;
}
/WEB-INF/xml/admin.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:context="http://www.springframework.org/schema/context"
xmlns:tx="http://www.springframework.org/schema/tx" xmlns:aop="http://www.springframework.org/schema/aop"
xsi:schemaLocation="http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd">
<bean id="iAdminBusinessManager" class="tr.com.server.business.admin.AdminBusinessManager">
<property name="iAdminDAO" ref="iAdminDAO"></property>
</bean>
<bean id="iAdminDAO" class="tr.com.server.persistance.admin.AdminDAO">
<property name="sessionFactory" ref="sessionFactory"></property>
</bean>
</beans>
web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
id="WebApp_ID" version="2.5">
<display-name>Index</display-name>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
</welcome-file-list>
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>WEB-INF/application-config.xml</param-value>
</context-param>
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<listener>
<listener-class>org.springframework.security.web.session.HttpSessionEventPublisher</listener-class>
</listener>
<servlet>
<servlet-name>springapp</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>springapp</servlet-name>
<url-pattern>*.htm</url-pattern>
</servlet-mapping>
<filter>
<filter-name>hibernateFilter</filter-name>
<filter-class>org.springframework.orm.hibernate3.support.OpenSessionInViewFilter</filter-class>
<init-param>
<param-name>singleSession</param-name>
<param-value>false</param-value>
</init-param>
<init-param>
<param-name>sessionFactoryBeanName</param-name>
<param-value>sessionFactory</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>hibernateFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<session-config>
<session-timeout>45</session-timeout>
</session-config>
<servlet>
<servlet-name>Jersey REST Service</servlet-name>
<servlet-class>com.sun.jersey.spi.container.servlet.ServletContainer</servlet-class>
<init-param>
<param-name>com.sun.jersey.config.property.packages</param-name>
<param-value>tr.com.server.webservice</param-value>
</init-param>
<init-param>
<param-name>com.sun.jersey.api.json.POJOMappingFeature</param-name>
<param-value>true</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>Jersey REST Service</servlet-name>
<url-pattern>/rest/*</url-pattern>
</servlet-mapping>
</web-app>
hibernate-config.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:context="http://www.springframework.org/schema/context"
xmlns:tx="http://www.springframework.org/schema/tx" xmlns:aop="http://www.springframework.org/schema/aop"
xsi:schemaLocation="http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd">
<!-- HIBERNATE CONFIGURATION START POINT -->
<bean id="sessionFactory"
class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean" >
<property name="packagesToScan" value="tr.com.server.model" />
<property name="hibernateProperties">
<props>
<prop key="hibernate.connection.pool_size">10</prop>
<prop key="hibernate.show_sql">true</prop>
<prop key="hibernate.connection.release_mode">auto</prop>
<prop key="hibernate.connection.characterEncoding">utf-8</prop>
<!--HSQL -->
<prop key="hibernate.connection.datasource">db2pool</prop>
<prop key="hibernate.transaction.factory_class">org.hibernate.transaction.JTATransactionFactory
</prop>
<prop key="hibernate.dialect">org.hibernate.dialect.DB2Dialect</prop>
</props>
</property>
</bean>
<!-- HIBERNATE CONFIGURATION END POINT -->
</beans>
springapp-servlet.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"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">
</beans>
application-config.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:context="http://www.springframework.org/schema/context"
xmlns:tx="http://www.springframework.org/schema/tx" xmlns:aop="http://www.springframework.org/schema/aop"
xsi:schemaLocation="http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd">
<import resource="hibernate-config.xml" />
<context:annotation-config />
<tx:annotation-driven transaction-manager="transactionManager" />
<aop:aspectj-autoproxy proxy-target-class="true" />
<context:component-scan base-package="tr.com.server.webservice" />
<import resource="xml/admin.xml" />
<bean id="transactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager">
<property name="sessionFactory" ref="sessionFactory" />
</bean>
</beans>

Answer 1

Two things I noticed in posted code:
AdminDAO a = new AdminDAO(); is not instantiation via spring factories. So the dependant spring beans (including session factories) will not be wired. get the AdminDAO beans from spring context look up or auto wiring.
#Transactional annotation will not be propagated via interface implementation or subclassing. Annotate each DAO class with #Transactional as well.