Spring 3.0: Unable to locate Spring NamespaceHandler for XML schema namespace

Question

My setup is fairly simple: I have a web front-end, back-end is spring-wired.

I am using AOP to add a layer of security on my rpc services.

It's all good, except for the fact that the web app aborts on launch:

  [java] SEVERE: Context initialization failed
     [java] org.springframework.beans.factory.parsing.BeanDefinitionParsingException: Configuration problem: Unable to locate Spring NamespaceHandler for XML schema namespace [http://www.springframework.org/schema/aop]
     [java] Offending resource: ServletContext resource [/WEB-INF/gwthandler-servlet.xml]

Here is the snippet from my xml config file:

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd">
    <aop:config>
        <aop:aspect id="security" ref="securityAspect" >
            <aop:pointcut id="securedServices" expression="@annotation(com.fb.boog.common.aspects.Secured)"/>
            <aop:before method="checkSecurity" pointcut-ref="securedServices"/>
        </aop:aspect>
    </aop:config>

I read over the internets that it may be my classloading the core of the problem. Doubtful, since here is my WEB-INF/lib directory:

./WEB-INF/lib
./WEB-INF/lib/aopalliance-alpha1.jar
./WEB-INF/lib/aspectj-1.6.6.jar
./WEB-INF/lib/commons-collections.jar
./WEB-INF/lib/commons-logging.jar
./WEB-INF/lib/ehcache-core-1.7.0.jar
./WEB-INF/lib/ejb3-persistence.jar
./WEB-INF/lib/hibernate
./WEB-INF/lib/hibernate/antlr.jar
./WEB-INF/lib/hibernate/asm.jar
./WEB-INF/lib/hibernate/bsh-2.0b1.jar
./WEB-INF/lib/hibernate/cglib.jar
./WEB-INF/lib/hibernate/dom4j.jar
./WEB-INF/lib/hibernate/freemarker.jar
./WEB-INF/lib/hibernate/hibernate-annotations.jar
./WEB-INF/lib/hibernate/hibernate-shards.jar
./WEB-INF/lib/hibernate/hibernate-tools.jar
./WEB-INF/lib/hibernate/hibernate.jar
./WEB-INF/lib/hibernate/jtidy-r8-20060801.jar
./WEB-INF/lib/jabsorb
./WEB-INF/lib/jabsorb/jabsorb-1.3.1.jar
./WEB-INF/lib/jta.jar
./WEB-INF/lib/jyaml-1.3.jar
./WEB-INF/lib/postgresql-8.4-701.jdbc4.jar
./WEB-INF/lib/sjsxp.jar
./WEB-INF/lib/spring
./WEB-INF/lib/spring/org.springframework.aop-3.0.0.RELEASE.jar
./WEB-INF/lib/spring/org.springframework.asm-3.0.0.RELEASE.jar
./WEB-INF/lib/spring/org.springframework.aspects-3.0.0.RELEASE.jar
./WEB-INF/lib/spring/org.springframework.beans-3.0.0.RELEASE.jar
./WEB-INF/lib/spring/org.springframework.context-3.0.0.RELEASE.jar
./WEB-INF/lib/spring/org.springframework.context.support-3.0.0.RELEASE.jar
./WEB-INF/lib/spring/org.springframework.core-3.0.0.RELEASE.jar
./WEB-INF/lib/spring/org.springframework.expression-3.0.0.RELEASE.jar
./WEB-INF/lib/spring/org.springframework.instrument-3.0.0.RELEASE.jar
./WEB-INF/lib/spring/org.springframework.instrument.tomcat-3.0.0.RELEASE.jar
./WEB-INF/lib/spring/org.springframework.jdbc-3.0.0.RELEASE.jar
./WEB-INF/lib/spring/org.springframework.jms-3.0.0.RELEASE.jar
./WEB-INF/lib/spring/org.springframework.orm-3.0.0.RELEASE.jar
./WEB-INF/lib/spring/org.springframework.oxm-3.0.0.RELEASE.jar
./WEB-INF/lib/spring/org.springframework.test-3.0.0.RELEASE.jar
./WEB-INF/lib/spring/org.springframework.transaction-3.0.0.RELEASE.jar
./WEB-INF/lib/spring/org.springframework.web-3.0.0.RELEASE.jar
./WEB-INF/lib/spring/org.springframework.web.portlet-3.0.0.RELEASE.jar
./WEB-INF/lib/spring/org.springframework.web.servlet-3.0.0.RELEASE.jar
./WEB-INF/lib/spring/org.springframework.web.struts-3.0.0.RELEASE.jar
./WEB-INF/lib/testng-5.11-jdk15.jar
./WEB-INF/web.xml

Answer 1

Encountered this error while using maven-shade-plugin, the solution was including:

META-INF/spring.schemas

and

META-INF/spring.handlers

transformers in the maven-shade-plugin when building...

    <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-shade-plugin</artifactId>
        <executions>
            <execution>
                <phase>package</phase>
                <goals>
                    <goal>shade</goal>
                </goals>
                <configuration>
                    <transformers>
                        <transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
                            <resource>META-INF/spring.handlers</resource>
                        </transformer>
                        <transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
                            <resource>META-INF/spring.schemas</resource>
                        </transformer>
                    </transformers>
                </configuration>
            </execution>
        </executions>
    </plugin>

(Credits: Idea to avoid that spring.handlers/spring.schemas get overwritten when merging multiple spring dependencies in a single jar)

Answer 2

http://maven.apache.org/plugins/maven-shade-plugin/examples/resource-transformers.html

I ran into a similar problem using the maven-shade-plugin. I found the solution to my problems in their example page above.

Answer 3

What IDE (if any) are you using? Does this happen when you're working within an IDE, or only on deployment? If it's deployment, it might be because whatever mechanism of deployment you use -- maven-assembly making a single JAR with dependencies is a known culprit -- is collapsing all your JARs into a single directory and the Spring schema and handler files are overwriting each other.

Answer 4

Did you try putting all your jars directly in the WEB-INF/lib dir instead of sub-dirs of that?

No WEB-INF/lib/spring/org.springframework.aop-3.0.0.RELEASE.jar, just WEB-INF/lib/org.springframework.aop-3.0.0.RELEASE.jar

Same with the rest of the jars.

Answer 5

I ran into a similar error, but refering to Spring Webflow in a newly created Roo project. The solution for me turned out to be (Project) / right-click / Maven / Enable Maven Dependencies (followed by some restarts and republishes to Tomcat).

It appeared that STS or m2Eclipse was failing to push all the spring webflow jars into the web app lib directory. I'm not sure why. But enabling maven dependency handling and then rebuilding seemed to fix the problem; the webflow jars finally get published and thus it can find the schema namespace references.

I investigated this by exploring the tomcat directory that the web app was published to, clicking into WEB-INF/lib/ while it was running and noticing that it was missing webflow jar files.