spring配置，获取实例对象，报错no beans name

spring配置文件中

<bean id="amAssetsGenerateHasystemBillForJsServiceImpl"
class="com.pccw.business.assetdatasyn.webservice.eam.js.eam_epa.service.impl.AmAssetsGenerateHasystemBillForJsServiceImpl">

</bean>

通过SpringBeanFactory.getBean("amAssetsGenerateHasystemBillForJsServiceImpl"); 得到实例

但是最好不写成全局变量，因为容器加载的先后顺序问题，容易报错 no beans name 

写在方法里面 

第二种，配置文件中配置了 

<bean id="amAssetsGenerateHasystemBillForJsServiceImpl"
class="com.pccw.business.assetdatasyn.webservice.eam.js.eam_epa.service.impl.AmAssetsGenerateHasystemBillForJsServiceImpl">
<property name="amEpaAssetsLogService">
<ref bean="amEpaAssetsLogService" />
</property>

</bean>

这样在类AmAssetsGenerateHasystemBillForJsServiceImpl中获取amEpaAssetsLogService的实例对象，通过get set 方法 ，全局的变量