Spring 3 with Drools 6 maven inconcistency

Question

I have a problem integrating Drools with Spring. I am trying to make a simple Hello World spring example, I reached a moment where my simple project refuses to compile. To work with Drools annotations like @KSession I need the drools-spring package, but it seems incompatible with Spring 3. As builder I use Maven. Here is how my .pom's looks like:

<dependencies>
        <!-- Drools -->
        <dependency>
            <groupId>org.drools</groupId>
            <artifactId>drools-compiler</artifactId>
            <version>6.0.0.Final</version>
        </dependency>
        <dependency>
            <groupId>org.drools</groupId>
            <artifactId>drools-core</artifactId>
            <version>6.0.0.Final</version>
        </dependency>
        <dependency>
            <groupId>org.drools</groupId>
            <artifactId>drools-decisiontables</artifactId>
            <version>6.0.0.Final</version>
        </dependency>
        <dependency>
        <groupId>org.kie</groupId>
            <artifactId>kie-api</artifactId>
            <version>6.0.0.Final</version>
        </dependency>
        <dependency>
            <groupId>org.kie</groupId>
            <artifactId>kie-internal</artifactId>
            <version>6.0.0.Final</version>
        </dependency>
        <dependency>
            <groupId>org.drools</groupId>
            <artifactId>drools-spring</artifactId>
            <version>6.0.0.Beta2</version>
        </dependency>

        <!-- Inject -->
        <dependency>
            <groupId>javax.inject</groupId>
            <artifactId>javax.inject</artifactId>
            <version>1</version>
        </dependency>

        <!-- Spring 3 dependencies -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>3.2.4.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
            <version>3.2.4.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>3.2.4.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-orm</artifactId>
            <version>3.2.4.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>3.2.4.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aop</artifactId>
            <version>3.2.4.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
            <version>3.2.4.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>3.2.4.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>3.2.4.RELEASE</version>
        </dependency>
</dependencies>

I use very simple case of controller class:

@Controller
@RequestMapping(value = "/")
public class BaseController extends AbstractController {

    private static final Logger log = Logger.getLogger(BaseController.class);

    @Autowired
    @KSession("ksession-rules")
    KieSession mySession;

    @RequestMapping(value = "/test")
    public @ResponseBody
    String test() {
        Fact myFact = new Fact();
        myFact.setFactNumber(20); //According to my rule when myFact.number>20 
                                  //then result will be set to "Hello World"

        mySession.insert(myFact);
        mySession.fireAllRules();

    return myFact.getResult();
    }
}

At this point I receive an error: "The hierarchy of the type BaseController is inconsistent".
I noticed that if I remove drools-spring from the dependency list the project compiles successfully. However without that package I cannot deploy my project, because the deployer demands the drools' class responsible for interpreting @KSession and that class is located in drools-spring package.

After some investigation it appears that my Drools session configuration seems to have nothing to do with the error above, so for the sake of succinctness I will not quote them. Instead of that I will mark that even if I don't make any modifications to the spring configuration and remove the KieSession from my example, making it a simple spring hello world example, I receive one and the same error out of my IDE (Eclipse): "The hierarchy of the type BaseController is inconsistent" and if I remove the drools-spring dependency the problem disappears.

It seems to me as dependency conflict.
Does anyone experienced similar problems with drools+spring?
Can someone suggest a solution to the problem?
Am I doing something wrong?

Thanks for the help!

Answer 1

After some research I found two things.

Drools' drools-spring package declares its own spring dependencies that are overriding my spring dependencies, which leads to spring malunctions. What I did is to manually remove the spring dependencies from drools-spring .pom file. Another mistake that I had in the upper example is that I didn't have kie-spring as dependency. Kie-spring is mandatory for one drools bean KModuleBeanFactoryPostProcessor, which is responsible to read my kmodule-kbase-ksession configuration from the spring configuration.

After resolving these two problems my project compiles now and I can see in the code that KModuleBeanFactoryPostProcessor defines that my configuration is being read and analized as I expected it to be.