无法在Maven环境中从JAXB生成类

Question

我在Maven环境中使用xjc插件，并尝试从Schema生成类，我能够从命令行使用xjc做到这一点（创建类），但是无法使用maven target generate-sources来做到这一点。
得到以下异常

[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)

谁能帮我找到这里缺少的内容。

Answer 1

如JAXB网站上所述，使用以下Maven插件：

        <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/

看来，您使用的是其他插件（堆栈跟踪上的org.codehaus.mojo.jaxb2.XjcMojo，Google将其引导至http://mojo.codehaus.org/jaxb2-maven-plugin/ ）。

Answer 2

由于它可以在命令行中运行，但不能在Maven中运行，因此具有冲突的类必须出现在类路径上。 有什么机会吗？

有关如何解决名称冲突的示例，请参见：

• 如何为docbook创建JAXB绑定

Answer 3

可能您有两个具有相同名称的子元素，因此生成的类名称是否相同？

在这种情况下，您可以使用模式注释自定义产生的类名称：

首先将以下名称空间添加到您的xsd中：

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

第二个为相关元素添加注释：

<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>