请教一下关于建立spring的bean的问题

[tdbrywwwcg]

我建立了一个bean
<bean id="testTarget" class="demo.service.dao.TestServiceSpring">
<property name="testDao"><ref local="testDAO"/></property>
</bean>
编译时报错，说testDao是个无效的属性
Invalid property 'testDao' of bean class [demo.service.dao.TestServiceSpring]: Property 'testDao' is not writable
这是由什么原因引起的？

[tdbrywwwcg]

testDAO这个bean已经配好了，应该不是这个问题。
<bean id="testService" class="org.springframework.transaction.interceptor.TransactionProxyFactoryBean">
<property name="transactionManager"><ref local="myTransactionManager"/></property>
<property name="target"><ref local="testTarget"/></property>
<property name="transactionAttributes">
<props>
<prop key="create*">PROPAGATION_REQUIRED,-TestException</prop>
</props>
</property>
</bean>

<!-- OrderTarget primary business object implementation -->
<bean id="testTarget" class="demo.service.dao.TestServiceSpring">
<property name="testDAO"><ref local="testDAO"/></property>
</bean>

<!-- DAO object: Hibernate implementation -->
<bean id="testDAO" class="demo.dao.hibernate.TestDao">
<property name="sessionFactory"><ref local="mySessionFactory"/></property>
</bean>

[tdbrywwwcg]

报错：
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'testService' defined in resource [/WEB-INF/spring.bean.xml] of ServletContext: Can't resolve reference to bean 'testTarget' while setting property 'target'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'testTarget' defined in resource [/WEB-INF/spring.bean.xml] of ServletContext: Error setting property values; nested exception is org.springframework.beans.NotWritablePropertyException: Invalid property 'testDAO' of bean class [demo.service.dao.TestServiceSpring]: Property 'testDAO' is not writable

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'testTarget' defined in resource [/WEB-INF/spring.bean.xml] of ServletContext: Error setting property values; nested exception is org.springframework.beans.NotWritablePropertyException: Invalid property 'testDAO' of bean class [demo.service.dao.TestServiceSpring]: Property 'testDAO' is not writable

org.springframework.beans.NotWritablePropertyException: Invalid property 'testDAO' of bean class [demo.service.dao.TestServiceSpring]: Property 'testDAO' is not writable

[tdbrywwwcg]

搞定了，原来是一个名字和它有一点小误差。

[wangyonghe]

<ref local="testDAO">是在本XML配置文件中寻找一个id为testDAO的bean你必须要配置