XJC错误提示“变色龙模式”

Question

我在对我的模式运行XJC时遇到问题。我已经从模式中删除了几乎所有的定义，只留下最少的定义来重现问题。当我对这个最小模式运行XJC时：

 1 <?xml version="1.0" encoding="utf-8"?>
 2 <xs:schema id="Catalog" xmlns:xs="http://www.w3.org/2001/XMLSchema" >
 3
 4   <xs:element name="Attribute">
 5     <xs:complexType>
 6       <xs:simpleContent>
 7         <xs:extension base="xs:string">
 8           <xs:attribute name="type" type="xs:string" />
 9         </xs:extension>
10       </xs:simpleContent>
11     </xs:complexType>
12   </xs:element>
13  
14   <xs:element name="SampleSet" substitutionGroup="Attribute"/>
15 </xs:schema>

我得到以下XJC错误：

C:\Users\mbmas_000\workspace\JMish>del src\jmish\jaxb\*.java

C:\Users\mbmas_000\workspace\JMish>xjc -d src -p jmish.jaxb JMish.xsd
parsing a schema...
compiling a schema...
[ERROR] A class/interface with the same name "jmish.jaxb.Attribute" is already in use. Use a class customization to resolve this conflict.
  line 5 of file:/C:/Users/mbmas_000/workspace/JMish/JMish.xsd

[ERROR] (Relevant to above error) another "Attribute" is generated from here.
  line 5 of file:/C:/Users/mbmas_000/workspace/JMish/JMish.xsd

[ERROR] (Relevant to above error) This confusing error happened most likely because the schema uses a technique called "chameleon schema", which causes a single definition to be loaded multiple times into different namespaces. See http://forums.java.net/jive/thread.jspa?threadID=18631 for more about this.
  line 5 of file:/C:/Users/mbmas_000/workspace/JMish/JMish.xsd

[ERROR] Two declarations cause a collision in the ObjectFactory class.
  line 5 of file:/C:/Users/mbmas_000/workspace/JMish/JMish.xsd

[ERROR] (Related to above error) This is the other declaration.
  line 5 of file:/C:/Users/mbmas_000/workspace/JMish/JMish.xsd

Failed to produce code.

C:\Users\mbmas_000\workspace\JMish>pause
Press any key to continue . . .

然而……如果我将SampleSet的名称更改为其他名称，如xSampleSet，XJC将不会出现任何错误。我使用的是JDK 1.7.0_45的XJC版本2.2.4-2。

我做错了什么吗？SampleSet是某种保留的元素名吗？

Answer 1

不，这不是变色龙模式问题。

我认为这是因为元素Attribute和它的匿名内部复杂类型都有自己的类。这两个名称都是Attribute。

尝试将复杂类型自定义为使用其他名称：

<jaxb:bindings schemaLocation="..." node="/xs:schema">
  <jaxb:bindings node="xs:element[@name='Attribute']/xs:complexType">
    <jaxb:class name="AttributeType"/>
  </jaxb:bindings>
</jaxb:bindings>

(粗略草图，未经测试。)

或者使用nameXmlTransform。

我不认为这是一个bug。