注解的EntityManager em，em老是报空值

Question

这是Spring 配置文件 <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalEntityManagerFactoryBean">
<property name="persistenceUnitName" value="SSJJPA"></property>
</bean>
<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
<property name="entityManagerFactory" ref="entityManagerFactory" />
</bean>

<tx:annotation-driven transaction-manager="transactionManager"/>

persistence.xml配置文件<persistence-unit name="SSJJPA"  transaction-type="RESOURCE_LOCAL">
    <provider>org.hibernate.ejb.HibernatePersistence</provider>
    <class>com.bean.Person</class> 
<properties>
  <property name="hibernate.dialect" value="org.hibernate.dialect.SQLServerDialect"/>
      <property name="hibernate.connection.driver_class" value="com.microsoft.sqlserver.jdbc.SQLServerDriver"/>
      <property name="hibernate.connection.url" value="jdbc:sqlserver://localhost:2010;databaseName=test"/>
      <property name="hibernate.connection.username" value="sa"/>
      <property name="hibernate.connection.password" value="aptech"/>
      <property name="hibernate.hbm2ddl.auto" value="update"/>
      <property name="hibernate.show_sql" value="true"></property> 
</properties>
  </persistence-unit>
</persistence>
 方法@Transactional
public class PersonServiceBean implements PersonService {

@PersistenceContext EntityManager em;
public void save(Person person){
System.out.println(em);
em.persist(person);
}



}
不知到为什么em 老是空值，哪位高手 帮小弟解决下 

Answer 1

@Service
@Transactional
public class MyBankServiceImpl implements MyBankService {@Autowired
private MyBankDao myBankDao;

Answer 2

还是不行 ，一直报这下面的错误
log4j:WARN No appenders could be found for logger (org.springframework.context.support.ClassPathXmlApplicationContext).
log4j:WARN Please initialize the log4j system properly.
null
Exception in thread "main" java.lang.NullPointerException
at com.service.bean.impl.PersonServiceBean.save(PersonServiceBean.java:25)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:310)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:182)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:149)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:106)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204)
at $Proxy11.save(Unknown Source)
at test.test.main(test.java:20)

Answer 3

 加上配置 告诉服务器 哪个包下的类要被自动注入
 <context:component-scan base-package="com.zwj.*.service" />