关于spring中的bean定义，parent属性是什么意思？该怎么处理

关于spring中的bean定义，parent属性是什么意思？
1.
<bean   id= "txProxyTemplate "   abstract= "true "
class= "org.springframework.transaction.interceptor.TransactionProxyFactoryBean ">
<property   name= "transactionAttributes ">
<props>
<prop   key= "create* "> PROPAGATION_REQUIRED </prop>
<prop   key= "delete* "> PROPAGATION_REQUIRED </prop>
<prop   key= "add* "> PROPAGATION_REQUIRED </prop>
<prop   key= "save* "> PROPAGATION_REQUIRED </prop>
<prop   key= "update* "> PROPAGATION_REQUIRED </prop>
<prop   key= "* "> PROPAGATION_REQUIRED,readOnly </prop>
</props>
</property>
</bean>


2.
<bean   id= "carnetMgr "   parent= "txProxyTemplate ">
<1property   name= "target ">
<bean   class= "ecustoms.carnet.app.biz.CarnetMgr ">
<property   name= "extensionHistoryDAO "   ref= "extensionHistoryDAO "/>
<property   name= "stockTransactionDAO "   ref= "stockTransactionDAO "/>
<property   name= "carnetDAO "   ref= "carnetDAO "/>
                        </bean>
</property>
</bean>
搞不明白！！！
高人指点一下！！

[解决办法]
表示继承的父类
如果有很多继承同一个父类的BEAN
那么在配置文件中实例那些BEAN时候可以省略掉父类已经注入的属性
[解决办法]
字bean定义继承父bean定义，它可以覆盖父bean的一些值，或者它需要的值。
[解决办法]
你 可以这么理解
[解决办法]
比如这些
<prop key= "create* "> PROPAGATION_REQUIRED </prop>
<prop key= "delete* "> PROPAGATION_REQUIRED </prop>
<prop key= "add* "> PROPAGATION_REQUIRED </prop>
<prop key= "save* "> PROPAGATION_REQUIRED </prop>
<prop key= "update* "> PROPAGATION_REQUIRED </prop>
<prop key= "* "> PROPAGATION_REQUIRED,readOnly </prop>
你在 实例子类时就已经继承了父类这些特性，无须在子bean定义中注入了。