如何以编程方式更新XSD并将元素添加到XSD中

Question

我需要用程序更新java中的现有XSD，如下所示：

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns="com/company/common" xmlns:xs="http://www.w3.org/2001/XMLSchema"
    targetNamespace="com/company/common/" elementFormDefault="qualified">
    <xs:include schemaLocation="DerivedAttributes.xsd" />
    <xs:element name="MyXSD" type="MyXSD" />
    <xs:complexType name="Containter1">
        <xs:sequence>
            <xs:element name="element1" type="element1" minOccurs="0"
                maxOccurs="unbounded" />
            <xs:element name="element2" type="element2" minOccurs="0"
                maxOccurs="unbounded" />
        </xs:sequence>
    </xs:complexType>
    <xs:complexType name="Containter2">
        <xs:sequence>
            <xs:element name="element3" type="Type1" minOccurs="0" />
            <xs:element name="element2" type="Type2" minOccurs="0" />
        </xs:sequence>
    </xs:complexType>
</xs:schema>

如何以编程方式将具有（name="element3"type="element 3"minOccurs="0"maxOccurs="unbounded"）的元素添加到容器1中？

我研究过DOM、Xerces、JAXB。。。但是，并没有真正明确的"正确"方法来遍历XSD并附加元素。Xerces看起来很有前景，但几乎没有相关文档。

谢谢！

Answer 1

以下是如何使用DOM:

    // parse file and convert it to a DOM
    Document doc = DocumentBuilderFactory
            .newInstance()
            .newDocumentBuilder()
            .parse(new InputSource("test.xml"));
    // use xpath to find node to add to
    XPath xPath = XPathFactory.newInstance().newXPath();
    NodeList nodes = (NodeList) xPath.evaluate("/schema/complexType[@name="Containter1"]",
            doc.getDocumentElement(), XPathConstants.NODESET);
    // create element to add
    org.w3c.dom.Element newElement = doc.createElement("xs:element");
    newElement.setAttribute("type", "element3");
    // set other attributes as appropriate
    nodes.item(0).appendChild(newElement);

    // output
    TransformerFactory
        .newInstance()
        .newTransformer()
        .transform(new DOMSource(doc.getDocumentElement()), new StreamResult(System.out));

关于JavaXML的文档相当丰富，可以找到许多教程和代码示例。请参阅Reading XML Data into a DOM，Java：how to located a element via xpath string on org.w3c.DOM.dococument，Java DOM-Inserting an element，after each for create and adding a new element，and What is the shortest way to pretty print a org.w3c.DOM.docDocument to stdout？以获取有关所用概念的更详细信息。