Springのbeanとクラスの関係

spring bean       
class A{} 
class B{} 
class C{} 

class Service{ 
private A a; 
private B b; 
private C c; 
//setter&getter 
} 
     bean： 
<beans> 
<bean id="a" class="package.A"> 
</bean> 
<bean id="b" class="package.B"> 
</bean> 
<bean id="c" class="package.C"> 
</bean> 
<bean id="service" class="package.Service"> 
   <property name="a" ref="a"/> 
   <property name="b" ref="b"/> 
   <property name="c" ref="c"/> 
</bean> 
</beans> 
    A,B,C，Service        
     
Service service=getService()  
A a=getService().getA()