[CXF-1982] Sub-resource locator fails on subtyping

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.1.3, 2.2
• Fix Version/s: 2.1.4, 2.2
• Component/s: JAX-RS

Environment

Tomcat 5.5.x

• Assignee: Sergey Beryozkin
• Reporter: Andrzej Michalec
• Created: 15/Jan/09 03:04
• Updated: 09/Feb/09 22:20
• Resolved: 29/Jan/09 14:19

Description

Attempt to use subresource locator with subtyping lead to following problem:

2009-01-15 03:31:28 org.apache.cxf.jaxrs.JAXRSServiceFactoryBean checkMethodDispatcher
WARNING: No resource methods found for resource class org.apache.cxf.jaxrs.model.ClassResourceInfo
2009-01-15 03:31:28 org.springframework.beans.factory.support.DefaultSingletonBeanRegistry destroySingletons
INFO: Destroying singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@1891d5d: defining beans [cxf,org.apache.cxf.bus.spring.BusApplicationListener,org.apache.cxf.bus.spring.BusWiringBeanFactoryPostProcessor,org.apache.cxf.bus.spring.Jsr250BeanPostProcessor,org.apache.cxf.bus.spring.BusExtensionPostProcessor,org.apache.cxf.resource.ResourceManager,org.apache.cxf.configuration.Configurer,org.apache.cxf.binding.BindingFactoryManager,org.apache.cxf.transport.DestinationFactoryManager,org.apache.cxf.transport.ConduitInitiatorManager,org.apache.cxf.wsdl.WSDLManager,org.apache.cxf.phase.PhaseManager,org.apache.cxf.workqueue.WorkQueueManager,org.apache.cxf.buslifecycle.BusLifeCycleManager,org.apache.cxf.endpoint.ServerRegistry,org.apache.cxf.endpoint.ServerLifeCycleManager,org.apache.cxf.endpoint.ClientLifeCycleManager,org.apache.cxf.transports.http.QueryHandlerRegistry,org.apache.cxf.endpoint.EndpointResolverRegistry,org.apache.cxf.headers.HeaderManager,org.apache.cxf.catalog.OASISCatalogManager,org.apache.cxf.endpoint.ServiceContractResolverRegistry,org.apache.cxf.transport.servlet.ServletTransportFactory,org.apache.cxf.jaxrs.JAXRSBindingFactory,jaxRsServer]; root of factory hierarchy
2009-01-15 03:31:28 org.springframework.web.context.ContextLoader initWebApplicationContext
SEVERE: Context initialization failed
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'jaxRsServer': Error setting property values; nested exception is org.springframework.beans.PropertyBatchUpdateException; nested PropertyAccessExceptions (1) are:
PropertyAccessException 1: org.springframework.beans.MethodInvocationException: Property 'serviceBeans' threw exception; nested exception is java.lang.NullPointerException
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1278)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1010)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:472)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory$1.run(AbstractAutowireCapableBeanFactory.java:409)
at java.security.AccessController.doPrivileged(Native Method)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:380)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:264)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:221)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:261)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:185)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:164)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:429)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:729)
...

To reproduces on CXF 2.2 use following code snippet (it also fails in CXF 2.1.3-stable using @ProduceMime):

@Produces("text/xml")
public class RootService {

@GET
@Path("/")
public String getThis()

{ return "<root>Root service</root>"; }

//@GET disabled to delegate to sub-resource
//when SubService is returned it works fine
//when java.lang.Object is returned it FAILS with Spring autowiring... weird
@Path("/sub")
public SubService getSub()

{ return new SubService(); }

}
-------------
@Produces("text/xml")
@XmlRootElement
public class SubService {

private String value = "sub value";

@GET
public Object getThis()

{ return this; }

@GET
@Path("/value")
public String getValue()

{ return value; }

}

I believe JAX-RS specification clearly points out that
"[...]implementation MUST dynamically determine the class of object returned rather than relying on the static sub-resource locator return type since the returned instance may be a subclass of the declared type with potentially different annotations[...]"

As reference see Jboss example returning java.lang.Object from locator: http://www.jboss.org/file-access/default/members/resteasy/freezone/docs/1.0-beta-7/userguide/html/JAX-RS_Resource_Locators_and_Sub_Resources.html

If there are some assumed limitation please provide workarounds for dynamic subresources.

(Side note: effective behavior is very similar to CXF-1762 suffering from method dispatching problems; maybe solution is similar).