在Java中获取具有名称空间的XML节点

Question

我有下一个XML：

<?xml version="1.0" encoding="ISO-8859-1" standalone="no"?>
<Invoice xmlns="urn:oasis:names:specification:ubl:schema:xsd:Invoice-2" 
         xmlns:cac="urn:oasis:names:specification:ubl:schema:xsd:CommonAggregateComponents-2"
         xmlns:cbc="urn:oasis:names:specification:ubl:schema:xsd:CommonBasicComponents-2"
         xmlns:ccts="urn:un:unece:uncefact:documentation:2"
         xmlns:ds="http://www.w3.org/2000/09/xmldsig#"
         xmlns:ext="urn:oasis:names:specification:ubl:schema:xsd:CommonExtensionComponents-2"
         xmlns:qdt="urn:oasis:names:specification:ubl:schema:xsd:QualifiedDatatypes-2"
         xmlns:sac="urn:sunat:names:specification:ubl:peru:schema:xsd:SunatAggregateComponents-1"
         xmlns:udt="urn:un:unece:uncefact:data:specification:UnqualifiedDataTypesSchemaModule:2"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <ext:UBLExtensions>
        <ext:UBLExtension>
            <ext:ExtensionContent>
                <!-- SOME CODE HERE -->
            </ext:ExtensionContent>
        </ext:UBLExtension>
        <ext:UBLExtension>
            <ext:ExtensionContent>
                <!-- I WANT TO GET THIS NODE -->
            </ext:ExtensionContent>
        </ext:UBLExtension>
    </ext:UBLExtensions>

如何获得此节点？我试过了

Document doc = dbf.newDocumentBuilder().parse(new FileInputStream(PATH_TO_MY_XML));
NodeList nodes = doc.getDocumentElement().getElementsByTagNameNS("*", "UBLExtension");

但它返回一个空数组。我该怎么做？

Answer 1

您需要确保XML解析器支持名称空间。

您还应该确保关闭FileInputStream，最好使用try-with-resources。

DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
dbf.setNamespaceAware(true);

Document doc;
try (InputStream xmlStream = new FileInputStream(PATH_TO_MY_XML)) {
    doc = dbf.newDocumentBuilder().parse(xmlStream);
}
NodeList nodes = doc.getDocumentElement().getElementsByTagNameNS("*", "UBLExtension");