ref a bean produced by a factory bean from constructor-arg

[manifoldronin]

(I'm running the spring.jar and spring-sandbox.jar updated from the Spring RCP CVS as of tonight)
In my standalone application test setup, I have this in order to load some DBUnit data set:

  <bean id="data-set-input-stream" class="org.springframework.beans.factory.config.MethodInvokingFactoryBean">
    <property name="staticMethod"><value>java.lang.ClassLoader.getSystemResourceAsStream</value></property>
    <property name="arguments">
      <list>
        <value>/default-dataset.xml</value>
      </list>
    </property>
  </bean>

  <bean id="direct-input-stream" class="java.io.FileInputStream">
    <constructor-arg><value>E&#58;\default-dataset.xml</value></constructor-arg>
  </bean>

  <bean id="data-set" class="org.dbunit.dataset.xml.FlatXmlDataSet">
    <constructor-arg type="java.io.InputStream"><ref bean="data-set-input-stream"/></constructor-arg>
    <constructor-arg type="boolean"><value>false</value></constructor-arg>
  </bean>

Upon loading this app context, I got a bean instantiation error because no matching constructors were found -

04 Nov 2004 22:14:56,953 DEBUG [main] org.springframework.beans.factory.support.DefaultListableBeanFactory  - Ignoring constructor [public org.dbunit.dataset.xml.FlatXmlDataSet(java.io.File,boolean) throws java.io.IOException,org.dbunit.dataset.DataSetException] of bean 'data-set': could not satisfy dependencies. Detail: Error creating bean with name 'data-set' defined in class path resource [global-context.xml]: Unsatisfied dependency expressed through constructor argument with index 0 of type [java.io.File]: Did you specify the correct bean references as generic constructor arguments?
04 Nov 2004 22:14:56,953 DEBUG [main] org.springframework.beans.factory.support.DefaultListableBeanFactory  - Ignoring constructor [public org.dbunit.dataset.xml.FlatXmlDataSet(java.net.URL,boolean) throws java.io.IOException,org.dbunit.dataset.DataSetException] of bean 'data-set': could not satisfy dependencies. Detail: Error creating bean with name 'data-set' defined in class path resource [global-context.xml]: Unsatisfied dependency expressed through constructor argument with index 0 of type [java.net.URL]: Did you specify the correct bean references as generic constructor arguments?
04 Nov 2004 22:14:56,953 DEBUG [main] org.springframework.beans.factory.support.DefaultListableBeanFactory  - Ignoring constructor [public org.dbunit.dataset.xml.FlatXmlDataSet(java.io.Reader,boolean) throws java.io.IOException,org.dbunit.dataset.DataSetException] of bean 'data-set': could not satisfy dependencies. Detail: Error creating bean with name 'data-set' defined in class path resource [global-context.xml]: Unsatisfied dependency expressed through constructor argument with index 0 of type [java.io.Reader]: Did you specify the correct bean references as generic constructor arguments?
04 Nov 2004 22:14:56,953 DEBUG [main] org.springframework.beans.factory.support.DefaultListableBeanFactory  - Ignoring constructor [public org.dbunit.dataset.xml.FlatXmlDataSet(java.io.Reader,java.io.Reader) throws java.io.IOException,org.dbunit.dataset.DataSetException] of bean 'data-set': could not satisfy dependencies. Detail: Error creating bean with name 'data-set' defined in class path resource [global-context.xml]: Unsatisfied dependency expressed through constructor argument with index 0 of type [java.io.Reader]: Did you specify the correct bean references as generic constructor arguments?
04 Nov 2004 22:14:56,953 DEBUG [main] org.springframework.beans.factory.support.DefaultListableBeanFactory  - Ignoring constructor [public org.dbunit.dataset.xml.FlatXmlDataSet(java.io.Reader,org.dbunit.dataset.IDataSet) throws java.io.IOException,org.dbunit.dataset.DataSetException] of bean 'data-set': could not satisfy dependencies. Detail: Error creating bean with name 'data-set' defined in class path resource [global-context.xml]: Unsatisfied dependency expressed through constructor argument with index 0 of type [java.io.Reader]: Did you specify the correct bean references as generic constructor arguments?
04 Nov 2004 22:14:56,953 DEBUG [main] org.springframework.beans.factory.support.DefaultListableBeanFactory  - Ignoring constructor [public org.dbunit.dataset.xml.FlatXmlDataSet(java.io.InputStream,boolean) throws java.io.IOException,org.dbunit.dataset.DataSetException] of bean 'data-set': could not satisfy dependencies. Detail: Failed to convert property value of type [org.springframework.util.MethodInvoker$VoidType] to required type [java.io.InputStream]
04 Nov 2004 22:14:56,953 DEBUG [main] org.springframework.beans.factory.support.DefaultListableBeanFactory  - Ignoring constructor [public org.dbunit.dataset.xml.FlatXmlDataSet(java.io.InputStream,java.io.InputStream) throws java.io.IOException,org.dbunit.dataset.DataSetException] of bean 'data-set': could not satisfy dependencies. Detail: Failed to convert property value of type [org.springframework.util.MethodInvoker$VoidType] to required type [java.io.InputStream]
04 Nov 2004 22:14:56,953 DEBUG [main] org.springframework.beans.factory.support.DefaultListableBeanFactory  - Ignoring constructor [public org.dbunit.dataset.xml.FlatXmlDataSet(java.io.InputStream,org.dbunit.dataset.IDataSet) throws java.io.IOException,org.dbunit.dataset.DataSetException] of bean 'data-set': could not satisfy dependencies. Detail: Failed to convert property value of type [org.springframework.util.MethodInvoker$VoidType] to required type [java.io.InputStream]
04 Nov 2004 22:14:56,953 DEBUG [main] org.springframework.beans.factory.support.DefaultListableBeanFactory  - Ignoring constructor [public org.dbunit.dataset.xml.FlatXmlDataSet(org.xml.sax.InputSource) throws java.io.IOException,org.dbunit.dataset.DataSetException] of bean 'data-set': could not satisfy dependencies. Detail: Error creating bean with name 'data-set' defined in class path resource [global-context.xml]: 2 constructor arguments specified but no matching constructor found in bean 'data-set' (hint: specify index arguments for simple parameters to avoid type ambiguities)
04 Nov 2004 22:14:56,953 DEBUG [main] org.springframework.beans.factory.support.DefaultListableBeanFactory  - Ignoring constructor [public org.dbunit.dataset.xml.FlatXmlDataSet(java.io.File) throws java.io.IOException,org.dbunit.dataset.DataSetException] of bean 'data-set': could not satisfy dependencies. Detail: Error creating bean with name 'data-set' defined in class path resource [global-context.xml]: 2 constructor arguments specified but no matching constructor found in bean 'data-set' (hint: specify index arguments for simple parameters to avoid type ambiguities)
04 Nov 2004 22:14:56,953 DEBUG [main] org.springframework.beans.factory.support.DefaultListableBeanFactory  - Ignoring constructor [public org.dbunit.dataset.xml.FlatXmlDataSet(java.net.URL) throws java.io.IOException,org.dbunit.dataset.DataSetException] of bean 'data-set': could not satisfy dependencies. Detail: Error creating bean with name 'data-set' defined in class path resource [global-context.xml]: 2 constructor arguments specified but no matching constructor found in bean 'data-set' (hint: specify index arguments for simple parameters to avoid type ambiguities)
04 Nov 2004 22:14:56,953 DEBUG [main] org.springframework.beans.factory.support.DefaultListableBeanFactory  - Ignoring constructor [public org.dbunit.dataset.xml.FlatXmlDataSet(java.io.Reader) throws java.io.IOException,org.dbunit.dataset.DataSetException] of bean 'data-set': could not satisfy dependencies. Detail: Error creating bean with name 'data-set' defined in class path resource [global-context.xml]: 2 constructor arguments specified but no matching constructor found in bean 'data-set' (hint: specify index arguments for simple parameters to avoid type ambiguities)
04 Nov 2004 22:14:56,953 DEBUG [main] org.springframework.beans.factory.support.DefaultListableBeanFactory  - Ignoring constructor [public org.dbunit.dataset.xml.FlatXmlDataSet(java.io.InputStream) throws java.io.IOException,org.dbunit.dataset.DataSetException] of bean 'data-set': could not satisfy dependencies. Detail: Error creating bean with name 'data-set' defined in class path resource [global-context.xml]: 2 constructor arguments specified but no matching constructor found in bean 'data-set' (hint: specify index arguments for simple parameters to avoid type ambiguities)

However if I change the first constructor-arg reference to "direct-input-stream", the bean is instantiated successfully.

I wonder what I'm missing here?
Thanks.

[irbouho]

You are getting this exception because java.lang.ClassLoader.getSystemResourceAsStream("/default-dataset.xml") returns null.
Spring has build-in support for resources which actually allows to use the following configuration:

<bean id="data-set" class="org.dbunit.dataset.xml.FlatXmlDataSet"> 
  <constructor-arg type="java.io.InputStream">
    <value>classpath&#58;default-dataset.xml</value>
  </constructor-arg> 
  <constructor-arg type="boolean">
    <value>false</value>
  </constructor-arg> 
</bean>

HTH

[jc]

<constructor-arg><value>E&#58;\default-dataset.xml</value></constructor-arg>

Shouldn't that be

E:\\default-dataset.xm 
or E:/default-dataset.xmll

?

[manifoldronin]

You are getting this exception because java.lang.ClassLoader.getSystemResourceAsStream("/default-dataset.xml") returns null.
Spring has build-in support for resources which actually allows to use the following configuration:

<bean id="data-set" class="org.dbunit.dataset.xml.FlatXmlDataSet"> 
  <constructor-arg type="java.io.InputStream">
    <value>classpath&#58;default-dataset.xml</value>
  </constructor-arg> 
  <constructor-arg type="boolean">
    <value>false</value>
  </constructor-arg> 
</bean>

That'd be very nice. I'll give it a try as soon as I get the chance. Thanks!

This leads to another question though - even the ref'ed bean is null, shouldn't it still be able to find the right constructor in this case, since I did give the arg types specifically? I mean, in general, what if null is a legitimate value for a constructor?

BTW, may I suggest a bit more logging be added to the mismatching constructor message? Currently it only prints out the expected type but not the type of the actual object.