<bean id="kenny"
    class="com.springinaction.springidol.Instrumentalist"
    init-method="tuneInstrument"
    destroy-method="cleanInstrument">
  <property name="song" value="Jingle Bells" />
  <property name="instrument" ref="saxophone" />
</bean>

 Consider the following abstract parent <bean> declaration:
<bean id="basePerformer" abstract="true">
  <property name="song" value="Somewhere Over the Rainbow" />
</bean>
This basePerformer bean declares the common song property that our two per-
formers  will  share.  But  notice  that  it  doesn’t  have  a  class  attribute  set.  That’s
okay,  because  each  child  bean  will  determine  its  own  type  with  its  own  class
attribute. The new declarations of taylor and stevie are as follows:
<bean id="taylor"
      class="com.springinaction.springidol.Vocalist"
      parent="basePerformer" />
<bean id="stevie"
      class="com.springinaction.springidol.Instrumentalist"
      parent="basePerformer">
  <property name="instrument" ref="guitar" />
</bean>

dispense
thermometer
before/after 后面动词是doing的形式
rummage