根据规范,从 Java 1.5 (5) 开始就提供支持。我相信 XInclude 支持依赖于命名空间感知,出于向后兼容性的原因,默认情况下它是关闭的。
public class XIncludeDemo {
private static final String XML = "<?xml version=\"1.0\"?>\n"
+ "<data xmlns=\"foo\" xmlns:xi=\"http://www.w3.org/2001/XInclude\">\n"
+ "<xi:include href=\"include.txt\" parse=\"text\"/>\n"
+ "</data>\n";
private static final String INCLUDE = "Hello, World!";
public static void main(String[] args) throws Exception {
// data
final InputStream xmlStream = new ByteArrayInputStream(XML
.getBytes("UTF-8"));
final InputStream includeStream = new ByteArrayInputStream(INCLUDE
.getBytes("UTF-8"));
// document parser
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
factory.setXIncludeAware(true);
factory.setNamespaceAware(true);
DocumentBuilder docBuilder = factory.newDocumentBuilder();
if (!docBuilder.isXIncludeAware()) {
throw new IllegalStateException();
}
docBuilder.setEntityResolver(new EntityResolver() {
@Override
public InputSource resolveEntity(String publicId, String systemId)
throws SAXException, IOException {
if (systemId.endsWith("include.txt")) {
return new InputSource(includeStream);
}
return null;
}
});
Document doc = docBuilder.parse(xmlStream);
// print result
Source source = new DOMSource(doc);
Result result = new StreamResult(System.out);
TransformerFactory transformerFactory = TransformerFactory
.newInstance();
Transformer transformer = transformerFactory.newTransformer();
transformer.transform(source, result);
}
}