mybean1.等级：

public class MyBean1{
      private MyBean2 bean2;
      public MyBean1(MyBean2 bean2){
         this.bean2=bean2;
      }
  }

xml格式：

<!-- Definition for bean1 -->
   <bean id = "bean1" class = "com.MyBean1">
      <constructor-arg ref = "bean2"/>
   </bean>

   <!-- Definition for bean2 -->
   <bean id = "bean2" class = "com.MyBean2"></bean>