Java XML-具有相同名称的嵌套元素

Question

How can I reach to elements which have same name and recursive inclusion using Java XML? This has worked in python ElementTree, but for some reason I need to get this running in Java.

I have tried:

String filepath = ("file.xml");
DocumentBuilderFactory docFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder docBuilder = docFactory.newDocumentBuilder();
Document doc = docBuilder.parse(filepath);

NodeList nl = doc.getElementsByTagName("*/*/foo");

Example

<foo>
  <foo>
     <foo>
     </foo>
  </foo>
</foo>

Answer 1

You seem to be under the impression that getElementsByTagName takes an XPath expression. It doesn't. As documented:

Returns a NodeList of all the Elements in document order with a given tag name and are contained in the document.

If you need to use XPath, you should look at the javax.xml.xpath package. Sample code:

Object set = xpath.evaluate("*/*/foo", doc, XPathConstants.NODESET);

NodeList list = (NodeList) set;
int count = list.getLength();
for (int i = 0; i < count; i++) {
    Node node = list.item(i);
    // Handle the node
}