Xerces-J を使用して XML スキーマを動的に生成しようとすると、次のエラーが発生します。
DocumentBuilderFactory dbfac = DocumentBuilderFactory.newInstance();
dbfac.setNamespaceAware(true);
DocumentBuilder docBuilder = dbfac.newDocumentBuilder();
Document doc = docBuilder.newDocument();
Element schema = doc.createElement("xs:schema");
schema.setAttribute("xmlns:xs", "http://www.w3.org/2001/XMLSchema");
doc.appendChild(schema);
Element e = doc.createElement("xs:element");
e.setAttribute("name", "test");
e.setAttribute("type", "xs:string");
schema.appendChild(e);
TransformerFactory transfac = TransformerFactory.newInstance();
Transformer trans = transfac.newTransformer();
trans.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "no");
trans.setOutputProperty(OutputKeys.INDENT, "yes");
//create string from xml tree
StringWriter sw = new StringWriter();
StreamResult result = new StreamResult(sw);
DOMSource source = new DOMSource(doc);
trans.transform(source, result);
String xmlString = sw.toString();
System.out.println(xmlString);
SchemaFactory schemaFactory = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
Schema schema1 = schemaFactory.newSchema(source);
Output is
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:element name="test" type="xs:string"/>
</xs:schema>
org.xml.sax.SAXParseException: s4s-elt-schema-ns: 要素 'xs:schema' の名前空間は、スキーマ名前空間 'http://www.w3.org/2001/XMLSchema' からのものでなければなりません。