如何通过命名空间获取具有相同标记名称的所有元素？

Question

我需要获取所有url元素的<media:content/>属性列表：

这是我的XML：

<rss version='2.0' xmlns:media='http://search.yahoo.com/mrss/'>
    <channel>
        <item>
            <media:group>
                <media:content url='https://valor'/>
            </media:group>
        </item>
        <item>
            <media:group>
                <media:content url='https://valor'/>
            </media:group>
        </item>    
    </channel>
</rss>

我试过了，但contents.getLength()返回0个元素

DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder = factory.newDocumentBuilder();

Document doc = builder.parse(inputStream);
NodeList contents = doc.getElementsByTagNameNS("http://search.yahoo.com/mrss/", "content");

此外，我尝试使用XPath ...但同样，contents.getLength()返回0个元素

XPathFactory factory2 = XPathFactory.newInstance();
XPath xpath = factory2.newXPath();
// XPathExpression expr = xpath.compile("//content"); 
XPathExpression expr = xpath.compile("//*[name()='content']");
NodeList contents = (NodeList) expr.evaluate(doc, XPathConstants.NODESET);

建议？

Answer 1

首先需要设置factory.setNamespaceAware(true)。然后getElementsByTagNameNS应该有效。