Spring Social M3: Issue with Scoped-Proxy

[skram]

I'm developing a sample application that will post feeds to Facebook periodically using Spring's Task Scheduler. I downloaded the latest spring-social-showcase project and extracted the relevant parts for my needs. I also setup a login mechanism using Spring Security 3.1 RC1's in-memory user-service.

I prefer to work via XML configuration than a Java-based configuration. In order for my application to access the currently authenticated user, I have to follow the following:

<bean id="connectionRepository" factory-method="createConnectionRepository" factory-bean="usersConnectionRepository" scope="request">
    <constructor-arg value="#{request.userPrincipal.name}" />
</bean>

Source: http://static.springsource.org/spring-social/docs/1.0.x/reference/html/connecting.html

The sample spring-social-showcase project uses a Java-based configuration, which is good IF there was also an XML-based configuration demo. Since most Spring users are used to XML-based, I just think that it's best that we include both options in the project. That's my first recommendation.

However, my real issue is when using the Expression Language "#{request.userPrincipal.name}". I have to setup my bean to use a "scope="request" which is understandable. However when I run my application, I get the following error:

java.lang.IllegalStateException: No thread-bound request found: Are you referring to request attributes outside of an actual web request, or processing a request outside of the originally receiving thread? ...

I'm aware of adding the <aop:scoped-proxy> but I'm wondering why it's never used or mentioned in the documentation (See http://static.springsource.org/sprin...onnecting.html). If it's not used, then it means it's not needed? But my application will not run without it.

So I added <aop:scoped-proxy>.

I now have the following:

<bean id="connectionRepository" factory-method="createConnectionRepository" 
			factory-bean="usersConnectionRepository" scope="request">
	    <constructor-arg value="#{request.userPrincipal.name}" />
	    <aop:scoped-proxy />
	</bean>

I'm able to login and get authenticated via Spring Security. However this still fails when I try to login to Facebook. Here's the simplified stacktrace:

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'scopedTarget.connectionRepository'

org.springframework.aop.framework.AopConfigException: Could not generate CGLIB subclass of class [class org.springframework.social.connect.jdbc.JdbcConnectionRepository]: Common causes of this problem include using a final class or a non-visible class;

java.lang.IllegalArgumentException: Superclass has no null constructors but no arguments were given

I have CGLIB on my classpath. I use Maven. To resolve the issue, I had to modify the aop-proxy element with:

<aop:scoped-proxy proxy-target-class="false"/>

Then my application works as expected. I understand what proxy-target-class="false" does. It's clearly stated in the docs.

I'm using the latest jars for Spring Social, Spring Security, and Spring Core:

Here's a snippet of my Maven properties section:

 
<properties>
    <springCoreVersion>3.1.0.M1</springCoreVersion>
    <springSocialVersion>1.0.0.M3</springSocialVersion>
    <springSecurityVersion>3.1.0.RC1</springSecurityVersion>
  </properties>

I'm wondering why I need to go such process when the documentation (Spring Social) isn't even using such? I might be missing a simple solution here? Thanks a lot

[Keith Donald]

We've recently updated the "spring-social-extending-existing-api" project in spring-social-samples to show XML-based config as an alternative to the Java @Configuration shown in spring-social-showcase.

Scoped proxies will not be required as long as you inject a Provider<ConnectionRepository> instead of the ConnectionRepository itself, where the JSR 330 Provider will make a lookup for the request-scoped bean when provider.get() is called. This is generally what I'd recommend, and is shown in the samples. If you do use a scoped-proxy, which would allow direct injection of a ConnectionRepository instance, yes, it should be an interface-based JDK dynamic proxy for the ConnectionRepository interface, and not a CGLIB one against the target class implementation. (I honestly still prefer injecting Provider<ConnectionRepository> for clarity that this is a request-scope object that needs to be fetched).

We should definitely update the documentation to clarify things in this area. Would you mind submitting a JIRA for this?

Keith

[skram]

Keith, thanks for the info. I will certainly file a JIRA regarding this. I will do it later tonight because I have to post another important issue.

You're right. The spring-social-showcase project is indeed using @Inject. I use @Resource in my projects. I think the documentation needs to clarify the ramifications of using @Inject, @Autowired, or @Resource. I'll note that in the JIRA later.

[skram]

Keith, I have filed a JIRA at https://jira.springsource.org/browse/SOCIAL-147

I hope the title is descriptive and accurate enough: Documentation for ConnectionRepository injection should be clarified when using scoped proxies and Provider