Java DOM : Number of first child nodes

Question

我有这样的 XML

<Cars>
    <Car name="abc" title="car length" length="20" type="type1" />
    <Car name="abc" title="car length" length="20" type="type2">
        <Car name="abc" title="car length" length="20" type="type1" />
        <Car name="abc" title="car length" length="20" type="type1" />
        <Car name="abc" title="car length" length="20" type="type1" />
    </Car> 
</Cars>

<小时/>

Element carNode = ...;
NodeList carList = carNode.getElementsByTagName("Car");
carList.getLength();

carList.getLength(); 给出所有后代节点的长度。所以在这种情况下它给出 5。 由于 Cars 有 2 个第一个子节点，我怎样才能得到这个长度，即 2？

Answer 1

这只能通过自己的代码或 XPath 进行。

XPath xpath = XPathFactory.newInstance().newXPath();
XPathExpression expr = xpath.compile("/Cars/Car");
NodeList nodes = (NodeList)  expr.evaluate(doc, XPathConstants.NODESET);