Unable to generate classes from JAXB in Maven environment

Question

I'm using the xjc plugin in Maven environment and trying to generate classes from the Schema I'm able to do this (Create classes) using xjc from command line, but unable to do the same using maven target generate-sources.
Getting the following exception

[ERROR] null[5,30]
org.xml.sax.SAXParseException: A class/interface with the same name "<className>" is already in use. Use a class customization
to resolve this conflict.
        at com.sun.tools.xjc.util.CodeModelClassFactory.createClass(CodeModelClassFactory.java:100)
        at com.sun.tools.xjc.util.CodeModelClassFactory.createClass(CodeModelClassFactory.java:61)
        at com.sun.tools.xjc.generator.bean.ImplStructureStrategy$1.createClasses(ImplStructureStrategy.java:42)
        at com.sun.tools.xjc.generator.bean.BeanGenerator.generateClassDef(BeanGenerator.java:371)
        at com.sun.tools.xjc.generator.bean.BeanGenerator.getClazz(BeanGenerator.java:403)
        at com.sun.tools.xjc.generator.bean.BeanGenerator$1.onBean(BeanGenerator.java:291)
        at com.sun.tools.xjc.generator.bean.BeanGenerator$1.onBean(BeanGenerator.java:299)
        at com.sun.tools.xjc.model.CClassInfo.accept(CClassInfo.java:352)
        at com.sun.tools.xjc.generator.bean.BeanGenerator.getContainer(BeanGenerator.java:281)
        at com.sun.tools.xjc.generator.bean.BeanGenerator.getUsedPackages(BeanGenerator.java:337)
        at com.sun.tools.xjc.generator.bean.BeanGenerator.<init>(BeanGenerator.java:169)
        at com.sun.tools.xjc.generator.bean.BeanGenerator.generate(BeanGenerator.java:151)
        at com.sun.tools.xjc.model.Model.generateCode(Model.java:230)
        at com.sun.tools.xjc.Driver.run(Driver.java:317)
        at org.codehaus.mojo.jaxb2.XjcMojo.execute(XjcMojo.java:301)
        at org.apache.maven.plugin.DefaultPluginManager.executeMojo(DefaultPluginManager.java:490)
        at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoals(DefaultLifecycleExecutor.java:694)
        at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoalWithLifecycle(DefaultLifecycleExecutor.java:556)
        at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoal(DefaultLifecycleExecutor.java:535)
        at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoalAndHandleFailures(DefaultLifecycleExecutor.java:387)
        at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeTaskSegments(DefaultLifecycleExecutor.java:348)
        at org.apache.maven.lifecycle.DefaultLifecycleExecutor.execute(DefaultLifecycleExecutor.java:180)
        at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:328)
        at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:138)
        at org.apache.maven.cli.MavenCli.main(MavenCli.java:362)
        at org.apache.maven.cli.compat.CompatibleMain.main(CompatibleMain.java:60)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at org.codehaus.classworlds.Launcher.launchEnhanced(Launcher.java:315)
        at org.codehaus.classworlds.Launcher.launch(Launcher.java:255)
        at org.codehaus.classworlds.Launcher.mainWithExitCode(Launcher.java:430)
        at org.codehaus.classworlds.Launcher.main(Launcher.java:375)

Can anyone help me find whats missing here.

Answer 1

As stated on the JAXB site, use the following Maven plugin:

        <plugin>
.           <groupId>org.jvnet.jaxb2.maven2</groupId>
            <artifactId>maven-jaxb2-plugin</artifactId>
            <executions>
                <execution>
                    <goals>
                        <goal>generate</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>

http://java.net/projects/maven-jaxb2-plugin/pages/Home

http://jaxb.java.net/

It seems, you're using a different plugin (org.codehaus.mojo.jaxb2.XjcMojo on your stack trace for which Google leads me to http://mojo.codehaus.org/jaxb2-maven-plugin/ ).

Answer 2

Since it works command line but not in Maven the class with the conflict must appear somewhere on your classpath. Any chance that is happening?

For an example on how to resolve name conflicts see:

• How do I create JAXB bindings for docbook

Answer 3

May be you have two sub-elements with the same name, so the generated class name is the same?

If this is the case, you can customized the produced class name using the schema annotations:

First add the following namespaces to your xsd:

<xs:schema xmlns:jaxb="http://java.sun.com/xml/ns/jaxb" jaxb:version="2.0">

Second add annotation for the relevant element:

<xs:complexType name="ComplexType">
    <xs:annotation><xs:appinfo>
       <jaxb:class name="MyClass"> 
           <jaxb:javadoc>This is my class.</jaxb:javadoc>
       </jaxb:class>
    </xs:appinfo></xs:annotation>
</xs:complexType>