Maven and Spring = Unable to create application context: Unable to locate Spring NamespaceHandler

Question

As per this question and this question, I'm getting the following error:

Unable to create application context: org.springframework.beans.factory.parsing.BeanDefinitionParsingException: Configuration problem: Unable to locate Spring NamespaceHandler for XML schema namespace [http://www.springframework.org/schema/context]
Offending resource: class path resource [floodstream-mastercontrol.conf.xml]

    at org.springframework.beans.factory.parsing.FailFastProblemReporter.error(FailFastProblemReporter.java:68)
    at org.springframework.beans.factory.parsing.ReaderContext.error(ReaderContext.java:85)
    at org.springframework.beans.factory.parsing.ReaderContext.error(ReaderContext.java:80)
    at org.springframework.beans.factory.xml.BeanDefinitionParserDelegate.error(BeanDefinitionParserDelegate.java:284)
    at org.springframework.beans.factory.xml.BeanDefinitionParserDelegate.parseCustomElement(BeanDefinitionParserDelegate.java:1332)
    at org.springframework.beans.factory.xml.BeanDefinitionParserDelegate.parseCustomElement(BeanDefinitionParserDelegate.java:1325)
    at org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentReader.parseBeanDefinitions(DefaultBeanDefinitionDocumentReader.java:136)
    at org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentReader.registerBeanDefinitions(DefaultBeanDefinitionDocumentReader.java:93)
    at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.registerBeanDefinitions(XmlBeanDefinitionReader.java:493)
    at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadBeanDefinitions(XmlBeanDefinitionReader.java:390)
    at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:334)
    at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:302)
    at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:143)
    at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:178)
    at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:149)
    at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:212)
    at org.springframework.context.support.AbstractXmlApplicationContext.loadBeanDefinitions(AbstractXmlApplicationContext.java:126)
    at org.springframework.context.support.AbstractXmlApplicationContext.loadBeanDefinitions(AbstractXmlApplicationContext.java:92)
    at org.springframework.context.support.AbstractRefreshableApplicationContext.refreshBeanFactory(AbstractRefreshableApplicationContext.java:130)
    at org.springframework.context.support.AbstractApplicationContext.obtainFreshBeanFactory(AbstractApplicationContext.java:465)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:395)
    at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:139)
    at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:83)
    at com.floodstream.wowza.mastercontrol.ServerListener.onServerCreate(ServerListener.java:30)
    at com.wowza.wms.server.Server.notifyServerCreate(Unknown Source)
    at com.wowza.wms.server.Server.start(Unknown Source)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:616)
    at com.wowza.wms.bootstrap.Bootstrap.startServer(Unknown Source)
    at com.wowza.wms.bootstrap.Bootstrap.main(Unknown Source)

Evidently, this is because of some bug in Maven, so here's my relevant POM:

<project>
    <!-- dependencies omitted for brevity -->

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>2.3.2</version>
                <configuration>
                    <source>1.5</source>
                    <target>1.5</target>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-dependency-plugin</artifactId>
                <version>2.3</version>
                <executions>
                    <execution>
                        <phase>package</phase>
                        <goals>
                            <goal>copy-dependencies</goal>
                        </goals>
                        <configuration>
                            <includeScope>runtime</includeScope>
                            <outputDirectory>${project.build.directory}/dependencies</outputDirectory>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-assembly-plugin</artifactId>
                <version>2.2.1</version>
                <executions>
                    <execution>
                        <goals>
                            <goal>single</goal>
                        </goals>
                        <phase>package</phase>
                        <configuration>
                            <descriptorRefs>
                                <descriptorRef>jar-with-dependencies</descriptorRef>
                            </descriptorRefs>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
</project>

Here is my application context:

<?xml version="1.0"?>
<beans xmlns="http://www.springframework.org/schema/beans"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xmlns:context="http://www.springframework.org/schema/context"
        xsi:schemaLocation="http://www.springframework.org/schema/beans
            http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
            http://www.springframework.org/schema/context
            http://www.springframework.org/schema/context/spring-context-3.0.xsd">

    <context:load-time-weaver/>
    <context:spring-configured/>

    <!-- beans omitted for brevity -->
</beans>

So, the goal is to combine things down into one JAR, but I think that might be the problem. Can someone explain what the problem is and how I can solve it? The other referenced questions had a different setup and goal, so I can't exactly follow their lead.

Answer 1

It's not a bug in maven, really. It's the result of a simplistic approach to building an uber-jar. Spring namespace handlers are registered in a file at META-INF/spring.handlers. Several of the spring modules have their own namespaces, and therefore you'll find this file in many different spring jars. If you don't merge these files together when building your uber-jar, you'll end up with one of them overwriting all the others, which obviously means you'll be missing some handlers. Any mechanism that lets you specify a spring.handlers file with all the required handlers in it will work. Building your own and ensuring it gets used in the final artifact would be one way.

Answer 2

I ran into the same issue. But thankfully my team mate had figured out how to create the uber jar to preserve the meta-inf files. Here is the pom fragment that helped me.

<configuration>
   <shadedArtifactAttached>true</shadedArtifactAttached>
   <shadedClassifierName>jar-with-dependencies</shadedClassifierName>
   <finalName>SpringWS-uber</finalName>
   <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>
        <transformer implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
            <resource>META-INF/spring.tooling</resource>
        </transformer>
    </transformers>
</configuration>