Синглтон и @Autowired возвращает NULL

У меня есть менеджер репозиториев, который управляет моими репозиториями. У меня есть @Autowired для создания экземпляров моих свойств, но они всегда равны нулю. Bean правильно настроены в моем xml. По какой причине?

public class RepositoryManager {

        private static RepositoryManager instance;

        private RepositoryManager()
        {
        }

       public static RepositoryManager Instance()
       {
            if(instance == null)
                 instance  = new RepositoryManager();

            return instance;
        }

        @Autowired
        private IUserRepository userRepository;

        @Autowired
        private IRoleRepository roleRepository;

        @Autowired
        private IAssetRepository assetRepository;

        public IUserRepository getUserRepository() {
            return userRepository;
        }

        public void setUserRepository(IUserRepository userRepository) {
            this.userRepository = userRepository;
        }

        public IRoleRepository getRoleReposttory() {
            return roleRepository;
        }

        public void setRoleReposttory(IRoleRepository roleRepository) {
            this.roleRepository = roleRepository;
        }

        public IAssetRepository getAssetRepository() {
            return assetRepository;
        }

        public void setAssetRepository(IAssetRepository assetRepository) {
            this.assetRepository = assetRepository;
        }
    }

dao.xml

    <!-- Scans within the base package of the application for @Components to configure as beans -->
    <context:component-scan base-package="com.cisco.badges.data.*" />

    <context:property-placeholder location="classpath:jdbc.properties"/>

    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
        <property name="driverClassName" value="${jdbc.driverClassName}"/>
        <property name="url" value="${jdbc.url}"/>
        <property name="username" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>
      </bean>

    <bean id="sessionFactory" class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">
        <property name="dataSource" ref="dataSource" />
        <property name="configurationClass" value="org.hibernate.cfg.AnnotationConfiguration"/>
        <property name="annotatedClasses">
          <list>
              <value>com.cisco.badges.data.domain.User</value>
              <value>com.cisco.badges.data.domain.Role</value>
              <value>com.cisco.badges.data.domain.Asset</value>
              <value>com.cisco.badges.data.domain.UserRole</value>
              <value>com.cisco.badges.data.domain.UserRole$UserRolePK</value>
              <value>com.cisco.badges.data.domain.UserAsset</value>
              <value>com.cisco.badges.data.domain.UserAsset$UserAssetPK</value>
          </list>
        </property>
        <property name="configLocation">
            <value>classpath:hibernate.cfg.xml</value>
        </property>
        <property name="hibernateProperties">
            <props>
                 <prop key="hibernate.show_sql">true</prop>
                <prop key="hibernate.format_sql">true</prop>
            </props>
        </property>
    </bean>

     <tx:annotation-driven/>

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

</beans>

userrepository.java

    @Repository("userRepository")
public class UserRepository extends
        BaseRepository<User, Long> implements
        IUserRepository {

    @Autowired
    public UserRepository(SessionFactory sessionFactory) {
        super(sessionFactory);
    }