java,xsd&marshalling:jre bug,我的错还是xsd问题？

Question

我在将JAXB模型树编组到xml文件时遇到了问题.

我使用xjc创建了这些模型类.我无法修改这些xml架构 - 它们是在外部定义的(类似于缺少答案的这个问题).

根据xjc(和其他xml工具),xml架构文件似乎是有效的.我在问是否

• 这是一个java/jre bug 或
• 我做错了什么 或者
• 如果架构文件有点错误

以及如何解决此问题.

我得到的例外是:

com.sun.istack.internal.SAXException2: "com.mypackage.A" is substituting "com.mypackage.BaseType", but "com.mypackage.A" is bound to an anonymous type.
    at com.sun.xml.internal.bind.v2.runtime.XMLSerializer.reportError(XMLSerializer.java:237)
    at com.sun.xml.internal.bind.v2.runtime.XMLSerializer.childAsXsiType(XMLSerializer.java:652)
    at com.sun.xml.internal.bind.v2.runtime.property.SingleElementNodeProperty.serializeBody(SingleElementNodeProperty.java:143)
    at com.sun.xml.internal.bind.v2.runtime.ClassBeanInfoImpl.serializeBody(ClassBeanInfoImpl.java:343)
    at com.sun.xml.internal.bind.v2.runtime.XMLSerializer.childAsXsiType(XMLSerializer.java:685)
    at com.sun.xml.internal.bind.v2.runtime.property.ArrayElementNodeProperty.serializeItem(ArrayElementNodeProperty.java:54)
    at com.sun.xml.internal.bind.v2.runtime.property.ArrayElementProperty.serializeListBody(ArrayElementProperty.java:157)
    at com.sun.xml.internal.bind.v2.runtime.property.ArrayERProperty.serializeBody(ArrayERProperty.java:144)
    at com.sun.xml.internal.bind.v2.runtime.ClassBeanInfoImpl.serializeBody(ClassBeanInfoImpl.java:343)
    at com.sun.xml.internal.bind.v2.runtime.ClassBeanInfoImpl.serializeBody(ClassBeanInfoImpl.java:335)
    at com.sun.xml.internal.bind.v2.runtime.XMLSerializer.childAsXsiType(XMLSerializer.java:685)
    at com.sun.xml.internal.bind.v2.runtime.property.SingleElementNodeProperty.serializeBody(SingleElementNodeProperty.java:143)
    at com.sun.xml.internal.bind.v2.runtime.ClassBeanInfoImpl.serializeBody(ClassBeanInfoImpl.java:343)
    at com.sun.xml.internal.bind.v2.runtime.ClassBeanInfoImpl.serializeBody(ClassBeanInfoImpl.java:335)
    at com.sun.xml.internal.bind.v2.runtime.XMLSerializer.childAsXsiType(XMLSerializer.java:685)
    at com.sun.xml.internal.bind.v2.runtime.property.SingleElementNodeProperty.serializeBody(SingleElementNodeProperty.java:143)
    at com.sun.xml.internal.bind.v2.runtime.ClassBeanInfoImpl.serializeBody(ClassBeanInfoImpl.java:343)
    at com.sun.xml.internal.bind.v2.runtime.XMLSerializer.childAsXsiType(XMLSerializer.java:685)
    at com.sun.xml.internal.bind.v2.runtime.property.SingleElementNodeProperty.serializeBody(SingleElementNodeProperty.java:143)
    at com.sun.xml.internal.bind.v2.runtime.ClassBeanInfoImpl.serializeBody(ClassBeanInfoImpl.java:343)
    at com.sun.xml.internal.bind.v2.runtime.XMLSerializer.childAsXsiType(XMLSerializer.java:685)
    at com.sun.xml.internal.bind.v2.runtime.property.SingleElementNodeProperty.serializeBody(SingleElementNodeProperty.java:143)
    at com.sun.xml.internal.bind.v2.runtime.ElementBeanInfoImpl$1.serializeBody(ElementBeanInfoImpl.java:146)
    at com.sun.xml.internal.bind.v2.runtime.ElementBeanInfoImpl$1.serializeBody(ElementBeanInfoImpl.java:116)
    at com.sun.xml.internal.bind.v2.runtime.ElementBeanInfoImpl.serializeBody(ElementBeanInfoImpl.java:318)
    at com.sun.xml.internal.bind.v2.runtime.ElementBeanInfoImpl.serializeRoot(ElementBeanInfoImpl.java:325)
    at com.sun.xml.internal.bind.v2.runtime.ElementBeanInfoImpl.serializeRoot(ElementBeanInfoImpl.java:61)
    at com.sun.xml.internal.bind.v2.runtime.property.ArrayReferenceNodeProperty.serializeListBody(ArrayReferenceNodeProperty.java:103)
    at com.sun.xml.internal.bind.v2.runtime.property.ArrayERProperty.serializeBody(ArrayERProperty.java:144)
    at com.sun.xml.internal.bind.v2.runtime.ClassBeanInfoImpl.serializeBody(ClassBeanInfoImpl.java:343)
    at com.sun.xml.internal.bind.v2.runtime.XMLSerializer.childAsXsiType(XMLSerializer.java:685)
    at com.sun.xml.internal.bind.v2.runtime.property.SingleElementNodeProperty.serializeBody(SingleElementNodeProperty.java:143)
    at com.sun.xml.internal.bind.v2.runtime.ClassBeanInfoImpl.serializeBody(ClassBeanInfoImpl.java:343)
    at com.sun.xml.internal.bind.v2.runtime.XMLSerializer.childAsXsiType(XMLSerializer.java:685)
    at com.sun.xml.internal.bind.v2.runtime.property.ArrayElementNodeProperty.serializeItem(ArrayElementNodeProperty.java:54)
    at com.sun.xml.internal.bind.v2.runtime.property.ArrayElementProperty.serializeListBody(ArrayElementProperty.java:157)
    at com.sun.xml.internal.bind.v2.runtime.property.ArrayERProperty.serializeBody(ArrayERProperty.java:144)
    at com.sun.xml.internal.bind.v2.runtime.ClassBeanInfoImpl.serializeBody(ClassBeanInfoImpl.java:343)
    at com.sun.xml.internal.bind.v2.runtime.XMLSerializer.childAsXsiType(XMLSerializer.java:685)
    at com.sun.xml.internal.bind.v2.runtime.ElementBeanInfoImpl$1.serializeBody(ElementBeanInfoImpl.java:141)
    at com.sun.xml.internal.bind.v2.runtime.ElementBeanInfoImpl$1.serializeBody(ElementBeanInfoImpl.java:116)
    at com.sun.xml.internal.bind.v2.runtime.ElementBeanInfoImpl.serializeBody(ElementBeanInfoImpl.java:318)
    at com.sun.xml.internal.bind.v2.runtime.ElementBeanInfoImpl.serializeRoot(ElementBeanInfoImpl.java:325)
    at com.sun.xml.internal.bind.v2.runtime.ElementBeanInfoImpl.serializeRoot(ElementBeanInfoImpl.java:61)
    at com.sun.xml.internal.bind.v2.runtime.XMLSerializer.childAsRoot(XMLSerializer.java:483)
    at com.sun.xml.internal.bind.v2.runtime.MarshallerImpl.write(MarshallerImpl.java:308)
    at com.sun.xml.internal.bind.v2.runtime.MarshallerImpl.marshal(MarshallerImpl.java:236)
    at javax.xml.bind.helpers.AbstractMarshallerImpl.marshal(AbstractMarshallerImpl.java:95)

(java 7 update 45)

Answer 1

TL; DR

java,xsd&marshalling:jre bug,我的错还是xsd问题？

这是你的错 :).继续阅读原因.

Java模型

下面是一个基于您的问题中暗示的Java模型,可用于生成您所看到的相同异常.

根

下面是一个具有一个属性的根对象.该属性的类型有两个子类.其中一个子类(B)对应于命名类型,另一个(A)对应于匿名类型.

package com.mypackage;

import javax.xml.bind.annotation.XmlRootElement;
@XmlRootElement
public class Root {

    private BaseType baseType;

    public BaseType getBaseType() {
        return baseType;
    }

    public void setBaseType(BaseType baseType) {
        this.baseType = baseType;
    }

}

BASETYPE

这是超级课程.它有两个子类:A和B.

package com.mypackage;

import javax.xml.bind.annotation.XmlSeeAlso;

@XmlSeeAlso({A.class, B.class})
public class BaseType {

}

一个

本A类对应于一个匿名的复杂类型.匿名类型用@XmlType(name="")注释表示.

package com.mypackage;

import javax.xml.bind.annotation.XmlType;

@XmlType(name="")
public class A extends BaseType {

}

乙

本B类对应于指定的复杂类型b.默认值与具有相同@XmlType(name="b").

package com.mypackage;

public class B extends BaseType {

}

演示代码 - 重现错误

演示

当类baseType上的Root属性是其中一个子类时,xsi:type将添加该属性以限定该元素(类似于Java中的强制转换).该实例需要对应于命名的复杂类型.在这种情况下A没有.

package com.mypackage;

import javax.xml.bind.*;

public class Demo {

    public static void main(String[] args) throws Exception {
        JAXBContext jc = JAXBContext.newInstance(Root.class);

        Root root = new Root();
        BaseType baseType = new A(); // Invalid Value
        root.setBaseType(baseType);

        Marshaller marshaller = jc.createMarshaller();
        marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
        marshaller.marshal(root, System.out);
    }

}

例外

这导致以下异常.正如所述,异常A不是有效的替代,BaseType因为它对应于匿名复杂类型,因为它对应于匿名类型,因此它没有该xsi:type属性的必要值.

Exception in thread "main" javax.xml.bind.MarshalException
 - with linked exception:
[com.sun.istack.internal.SAXException2: Instance of "com.mypackage.A" is substituting "com.mypackage.BaseType", but "com.mypackage.A" is bound to an anonymous type.]
    at com.sun.xml.internal.bind.v2.runtime.MarshallerImpl.write(MarshallerImpl.java:311)
    at com.sun.xml.internal.bind.v2.runtime.MarshallerImpl.marshal(MarshallerImpl.java:236)
    at javax.xml.bind.helpers.AbstractMarshallerImpl.marshal(AbstractMarshallerImpl.java:95)
    at com.mypackage.Demo.main(Demo.java:16)
Caused by: com.sun.istack.internal.SAXException2: Instance of "com.mypackage.A" is substituting "com.mypackage.BaseType", but "com.mypackage.A" is bound to an anonymous type.
    at com.sun.xml.internal.bind.v2.runtime.XMLSerializer.reportError(XMLSerializer.java:237)
    at com.sun.xml.internal.bind.v2.runtime.XMLSerializer.childAsXsiType(XMLSerializer.java:652)
    at com.sun.xml.internal.bind.v2.runtime.property.SingleElementNodeProperty.serializeBody(SingleElementNodeProperty.java:143)
    at com.sun.xml.internal.bind.v2.runtime.ClassBeanInfoImpl.serializeBody(ClassBeanInfoImpl.java:343)
    at com.sun.xml.internal.bind.v2.runtime.XMLSerializer.childAsSoleContent(XMLSerializer.java:582)
    at com.sun.xml.internal.bind.v2.runtime.ClassBeanInfoImpl.serializeRoot(ClassBeanInfoImpl.java:325)
    at com.sun.xml.internal.bind.v2.runtime.XMLSerializer.childAsRoot(XMLSerializer.java:483)
    at com.sun.xml.internal.bind.v2.runtime.MarshallerImpl.write(MarshallerImpl.java:308)
    ... 3 more

演示代码 - 有效

演示

如果不是A您指定了B与命名复杂类型对应的其他子类.

package com.mypackage;

import javax.xml.bind.*;

public class Demo {

    public static void main(String[] args) throws Exception {
        JAXBContext jc = JAXBContext.newInstance(Root.class);

        Root root = new Root();
        BaseType baseType = new B(); // Valid Value
        root.setBaseType(baseType);

        Marshaller marshaller = jc.createMarshaller();
        marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
        marshaller.marshal(root, System.out);
    }

}

产量

然后,您将看到所有内容都按预期工作,并且在对baseType属性进行编组时包含类型名称.

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<root>
    <baseType xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="b"/>
</root>