Java IDREF属性只能有本地ID值吗？

我有这样的元素

<xsd:element name="Car" type="carType"/>

<xsd:complexType name="carType">
    <xsd:complexContent>
        <xsd:extension base="basicType">
            <xsd:attribute name="motor" type="xsd:IDREF" use="required"/>
        </xsd:extension>
    </xsd:complexContent>
</xsd:complexType>

Intellij Idea说

无效的id引用

，当我运行程序时，我得到一个异常

There is no ID/IDREF binding for IDREF 

---

可能是我做错了什么？或者可能是

xsd:IDREF

等于

ref local

，因此我不能将其用于导入？

我是对的，

xsd:IDREF

等于ref local

关于

xsd:IDREF

你可以看到为什么它在这里相等-

<xsd:element name="ref">
        <xsd:annotation>
            <xsd:documentation><![CDATA[
    Defines a reference to another bean in this factory or an external
    factory (parent or included factory).
            ]]></xsd:documentation>
        </xsd:annotation>
        <xsd:complexType>
            <xsd:complexContent>
                <xsd:restriction base="xsd:anyType">
                    <xsd:attribute name="bean" type="xsd:string">
                        <xsd:annotation>
                            <xsd:documentation><![CDATA[
    The name of the referenced bean.
                            ]]></xsd:documentation>
                        </xsd:annotation>
                    </xsd:attribute>
                    **<xsd:attribute name="local" type="xsd:IDREF">**
                        <xsd:annotation>
                            <xsd:documentation><![CDATA[
    The name of the referenced bean. The value must be a bean ID and thus can 
    be checked by the XML parser. This is therefore the preferred technique 
    for referencing beans within the same bean factory XML file.
                            ]]></xsd:documentation>
                        </xsd:annotation>
                    </xsd:attribute>
                    <xsd:attribute name="parent" type="xsd:string">
                        <xsd:annotation>
                            <xsd:documentation><![CDATA[
    The name of the referenced bean in a parent factory.
                        ]]></xsd:documentation>
                        </xsd:annotation>
                    </xsd:attribute>
                </xsd:restriction>
            </xsd:complexContent>
        </xsd:complexType>
    </xsd:element>

****

它是对元素bean element

ref

的描述。正如我们所知，我们只能对当前XML文档中的元素使用

There is no ID/IDREF binding for IDREF 

<xsd:element name="ref">
        <xsd:annotation>
            <xsd:documentation><![CDATA[
    Defines a reference to another bean in this factory or an external
    factory (parent or included factory).
            ]]></xsd:documentation>
        </xsd:annotation>
        <xsd:complexType>
            <xsd:complexContent>
                <xsd:restriction base="xsd:anyType">
                    <xsd:attribute name="bean" type="xsd:string">
                        <xsd:annotation>
                            <xsd:documentation><![CDATA[
    The name of the referenced bean.
                            ]]></xsd:documentation>
                        </xsd:annotation>
                    </xsd:attribute>
                    **<xsd:attribute name="local" type="xsd:IDREF">**
                        <xsd:annotation>
                            <xsd:documentation><![CDATA[
    The name of the referenced bean. The value must be a bean ID and thus can 
    be checked by the XML parser. This is therefore the preferred technique 
    for referencing beans within the same bean factory XML file.
                            ]]></xsd:documentation>
                        </xsd:annotation>
                    </xsd:attribute>
                    <xsd:attribute name="parent" type="xsd:string">
                        <xsd:annotation>
                            <xsd:documentation><![CDATA[
    The name of the referenced bean in a parent factory.
                        ]]></xsd:documentation>
                        </xsd:annotation>
                    </xsd:attribute>
                </xsd:restriction>
            </xsd:complexContent>
        </xsd:complexType>
    </xsd:element>