Dependency Injection is working at Mule application startup. Objects are getting null, when a request received and Failing by throwing NullEx - spring

Question

<?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">
<context:component-scan base-package="com.example.hibernate" />
<bean id="myDataSource" class="org.apache.commons.dbcp.BasicDataSource">
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost:3306/emp" />
<property name="username" value="root" />
<property name="password" value="admin" />
</bean>
<bean id="sessionFactory"
class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean" autowire = "byname">
<property name="dataSource" ref="myDataSource" />
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect
</prop>
<prop key="hibernate.connection.pool_size">20</prop>
<prop key="hibernate.show_sql">true</prop>
<prop key="hibernate.hbm2ddl.auto">update</prop>
</props>
</property>
<property name="mappingResources">
<list>
<value>Departments.hbm.xml</value>
</list>
</property>
</bean>
<bean id ="employeeDAO" class = "com.example.hibernate.dao.EmployeeDAOImpl" autowire = "byname"/>
</beans>
And here is Mflow
<?xml version="1.0" encoding="UTF-8"?>
<mule xmlns:json="http://www.mulesoft.org/schema/mule/json"
xmlns:data-mapper="http://www.mulesoft.org/schema/mule/ee/data-mapper"
xmlns:http="http://www.mulesoft.org/schema/mule/http" xmlns:tracking="http://www.mulesoft.org/schema/mule/ee/tracking"
xmlns="http://www.mulesoft.org/schema/mule/core" xmlns:doc="http://www.mulesoft.org/schema/mule/documentation" xmlns:context="http://www.springframework.org/schema/context"
xmlns:spring="http://www.springframework.org/schema/beans" version="EE-3.4.1"
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-current.xsd
http://www.mulesoft.org/schema/mule/core http://www.mulesoft.org/schema/mule/core/current/mule.xsd
http://www.mulesoft.org/schema/mule/http http://www.mulesoft.org/schema/mule/http/current/mule-http.xsd
http://www.mulesoft.org/schema/mule/ee/tracking http://www.mulesoft.org/schema/mule/ee/tracking/current/mule-tracking-ee.xsd
http://www.mulesoft.org/schema/mule/ee/data-mapper http://www.mulesoft.org/schema/mule/ee/data-mapper/current/mule-data-mapper.xsd
http://www.mulesoft.org/schema/mule/json http://www.mulesoft.org/schema/mule/json/current/mule-json.xsd
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd
http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.2.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd">
<spring:beans>
<spring:import resource="DBConfigurations.xml" />
</spring:beans>
<data-mapper:config name="getEmployeeDetailsReq"
transformationGraphPath="getEmployeeDetailsReq.grf" doc:name="getEmployeeDetailsReq" />
<data-mapper:config name="getEmployeeDetailsResponse" transformationGraphPath="getEmployeeDetailsResponse.grf" doc:name="getEmployeeDetailsResponse"/>
<flow name="EmployeeDetailsFlow" doc:name="EmployeeDetailsFlow">
<http:inbound-endpoint exchange-pattern="request-response"
address="http://localhost:9090/getEmployeeDetails" doc:name="Receive" />
<object-to-string-transformer doc:name="Object to String" />
<data-mapper:transform config-ref="getEmployeeDetailsReq"
doc:name="getEmployeeDetailsReq" />
<component doc:name="GetTemplateInfo"
class="com.example.hibernate.dao.GetEmployeeDetails" />
<data-mapper:transform config-ref="getEmployeeDetailsResponse" returnClass="java.lang.String" doc:name="getEmployeeDetailsResponse"/>
<json:object-to-json-transformer
doc:name="Object to JSON" />
</flow>
</mule>
Here is my Java Component
package com.example.hibernate.dao;
import org.mule.api.MuleEventContext;
import org.mule.api.lifecycle.Callable;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import com.example.hibernate.Employee;
public class GetEmployeeDetails implements Callable{
#Autowired
#Qualifier("employeeDAO")
private EmployeeDAO dao;
#Override
public Object onCall(MuleEventContext eventContext) throws Exception {
Employee emp = (Employee)eventContext.getMessage().getPayload();
return dao.getEmployeeDetailsById(emp.getId());
}
}
I have tried to inject object using autowire and also by using spring setter injection.
In both the scenarios by adding Syso in constructor and setter method I have noticed, that the object is getting injected at the time of application start up. Sysos are getting printed in the console.
When I send a request, object is getting null and failing by throwing NullPointerException.
Even the same is not working in Service classes as well.
Can any one help me out?
Thanks in advance.

Answer 1

Do you mind trying the following?
Add this to DBConfiguration.xml:
<bean id="getEmployeeDetails"
class="com.example.hibernate.dao.GetEmployeeDetails" />
And change the flow to:
<component>
<spring-object bean="getEmployeeDetails"/>
</component>