NullPointerException from DAO by using crudRepositoy - spring

Question

i got java.lang.NullPointerException by using CrudRepository
my project looks like this:
strut2 action
service
repository
domain
class Action {
#Autowired MyService service;
public String execute(){
service.getList();
return "ok";
}
}
interface Service {
List getList();
}
#org.springframework.stereotype.Service
class ServiceImpl implements Service {
#Autowired MyRepository repo;
List getList(){
return (List)repo.findAll();
}
}
package com.mycompany.repositories;
interface MyRepository extends CrudRepository<MyPojo, String>{}
here is the config:
<?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:context="http://www.springframework.org/schema/context"
xmlns:jpa="http://www.springframework.org/schema/data/jpa"
xsi:schemaLocation=" http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.1.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-3.1.xsd
http://www.springframework.org/schema/data/jpa
http://www.springframework.org/schema/data/jpa/spring-jpa.xsd">
<jpa:repositories base-package="com.mycompany.repositories" />
<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager" >
<property name="entityManagerFactory" ref="entityManagerFactory" />
<property name="jpaDialect">
<bean class="org.springframework.orm.jpa.vendor.HibernateJpaDialect" />
</property>
</bean>
<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
<property name="dataSource" ref="dataSource" />
<property name="persistenceUnitName" value="unit-name" />
<property name="jpaVendorAdapter">
<bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
<property name="showSql" value="true" />
<property name="generateDdl" value="true" />
<property name="database" value="POSTGRESQL"/>
</bean>
</property>
</bean>
<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="username" value="root" />
<property name="password" value="root" />
<property name="driverClassName" value="org.postgresql.Driver" />
<property name="url" value="jdbc:postgresql://127.0.0.1:5432/mydb" />
</bean>
<bean class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor"></bean>
<tx:annotation-driven transaction-manager="transactionManager" />
</beans>
I'm new here, and everytime i call the Action class, the service is injected, but MyRepository is alway null.
could someone help me with please, if you need more infos, pls let me know, thx!
EDIT 1
StackTrace:
2012-06-26 15:33:32,041 INFO - com.myproject.action.project.preparation.ApplicationAction - listing application...
java.lang.NullPointerException
at com.myproject.service.impl.ApmProjectPreparationServiceImpl.getAllApplications(ProjectPreparationServiceImpl.java:41)
at com.myproject.action.project.preparation.ApplicationAction.listAction(ApplicationAction.java:67)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:453)
at com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:292)
I also tried to debug it by myself. i found on the class ServiceImpl that the #Autowired MyRepository repo is null.

Answer 1

Seems i found the answer, thank #MartenDeinum from Spring Forum.
here are the tricks:
i am using struts2 for the GUI, so i need struts2 spring plugin to rewrite the struts2 object factory, so that the spring can find struts action.
i added this config for #Service
<context:component-scan base-package="com.myproject" />
basically i also need
<jpa:repositories base-package="com.myproject.repository" />
to find CrudRepository.
hope this can help others.