Question

org.xml.sax.SAXParseException: cvc-complex-type.2.4.c: The matching wildcard is strict, but no declaration can be found for element 'drools:grid-node'. 

I’m getting this error when I add a grid-node and ksession to my spring xml. I did some searching and looks like it a classpath issue. What dependency am I missing here ?

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:camel="http://camel.apache.org/schema/spring"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:jaxrs="http://cxf.apache.org/jaxrs"
    xmlns:drools="http://drools.org/schema/drools-spring"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans.xsd
       http://camel.apache.org/schema/spring
       http://camel.apache.org/schema/spring/camel-spring.xsd
       http://www.springframework.org/schema/context 
       http://www.springframework.org/schema/context/spring-context-3.0.xsd
       http://www.springframework.org/schema/mvc
       http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd
       http://cxf.apache.org/jaxrs http://cxf.apache.org/schemas
       http://cxf.apache.org/jaxrs http://cxf.apache.org/schemas/jaxrs.xsd
       http://drools.org/schema/drools-spring org/drools/container/spring
       http://drools.org/schema/drools-spring org/drools/container/spring/drools-spring-1.2.0.xsd">


    <drools:grid-node id="node1"/>
    <drools:ksession id="ksession1" type="stateful" kbase="kbase1" node="node1" />

My pom.xml has the following for Drools.

               <dependency>
        <groupId>org.drools</groupId>
        <artifactId>drools-camel</artifactId>
        <version>${drools.version}</version>
        <exclusions>
            <!-- This ensures that we use the latest version of Spring jars and not 
                the one that comes with drools.version. -->
            <exclusion>
                <groupId>org.springframework</groupId>
                <artifactId>spring</artifactId>
            </exclusion>

            <exclusion>
                <groupId>org.apache.camel</groupId>
                <artifactId>camel-core</artifactId>
            </exclusion>

            <exclusion>
              <groupId>org.apache.camel</groupId>
              <artifactId>camel-spring</artifactId>
            </exclusion>



            <exclusion>
                <artifactId>camel-xstream</artifactId>
                <groupId>org.apache.camel</groupId>
            </exclusion>
        </exclusions>
    </dependency>
    <dependency>
        <groupId>org.drools</groupId>
        <artifactId>knowledge-api</artifactId>
        <version>${drools.version}</version>
    </dependency>

    <dependency>
        <groupId>org.drools</groupId>
        <artifactId>drools-core</artifactId>
        <version>${drools.version}</version>
    </dependency>


    <dependency>
        <groupId>org.drools</groupId>
        <artifactId>drools-compiler</artifactId>
        <version>${drools.version}</version>
    </dependency>


    <dependency>
        <groupId>org.drools</groupId>
        <artifactId>drools-spring</artifactId>
        <version>${drools.version}</version>
    </dependency>

Answer 1

This error is being issued because the Drools XSD can’t be located. In this comment in the Drools user list, it is stated that the XSD’s aren’t publicly available, and the xsi:schemaLocation attribute in the XML is mapping that XSD to http://drools.org/schema/drools-spring org/drools/container/spring/drools-spring-1.2.0.xsd, which doesn’t resolve to the proper XSD.

Spring should be automatically handling the XSD resolution given the xmlns:drools="http://drools.org/schema/drools-spring" attribute. One of the Drools JARs should be including a META-INF/spring.handlers file defining the XSD mapping for the drools namespace. Something along the lines of :

http://drools.org/schema/drools-spring=some.classpath.visible.package.xsdfile.xsd

Which should be automatically handling the XSD file included in the Drools JARs.

Try removing the last two lines of your xsi:schemaLocation attribute in order to let Spring automatically resolve the XSD.

Some related links:

• Spring schemaLocation fails when there is no internet connection. Specially David Resnick’s answer.
• Spring reference’s Appendix D.5 Registering the handler and the schema.

Of course, you could also extract that XSD from the JAR file, place it in an accessible directory from your classpath and use a classpath relative URL in xsi:schemaLocation.

By the way, it’s probably a copy&paste error, but your <beans> element is missing its closing tag.

EDIT : It seems that Drools wasn’t providing the spring.handlers properly (at least as of December 2010, see Drools + Spring without internet ). You might need to dig through the JARs to get the XSD and reference it directly in xsi:schemaLocation.