Problem passing null parameters

[teknokrat]

The following definition works

	<bean id="jmxConnector" class="javax.management.remote.JMXConnectorFactory" factory-method="newJMXConnector">
		<constructor-arg><ref bean="jmxUrl"/></constructor-arg>
		<constructor-arg><bean class="java.util.HashMap"/></constructor-arg>
	</bean>

But

	<bean id="jmxConnector" class="javax.management.remote.JMXConnectorFactory" factory-method="newJMXConnector">
		<constructor-arg><ref bean="jmxUrl"/></constructor-arg>
		<constructor-arg><null/></constructor-arg>
	</bean>

fails with

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'jmxConnectorServer' defined in file [/usr/local/workspace/LinkBuilder/web/WEB-INF/applicationContext.xml]: Instantiation of bean failed; nested exception is org.springframework.beans.factory.BeanDefinitionStoreException: Cannot find matching factory method 'newJMXConnectorServer' on class class javax.management.remote.JMXConnectorServerFactory
org.springframework.beans.factory.BeanDefinitionStoreException: Cannot find matching factory method 'newJMXConnectorServer' on class class javax.management.remote.JMXConnectorServerFactory
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:399)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:246)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:205)
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:204)

I have the latest spring 1.1.1 installed.

I presume this is a bug, or am I doing something wrong?

thanks

[ojolly]

Sometimes there is an ambiguity with arguments of a constructor which can't be solved by Spring. Do no assume that it tries with the very same order you specified in the configuration. It tries to change the order of the given arguments to match a constructor.
Anyway, in your case, introducing a null value makes it ambigute and you can force the order using the attribute index of each constructor-arg, like

 <constructor-arg index="0"><ref bean="jmxUrl"/></constructor-arg>
 <constructor-arg index="1"><bean class="java.util.HashMap"/></constructor-arg>

HTH

Olivier

[teknokrat]

That did the trick

thank you