在 Java 中使用 XPath 解析 XML
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Parsing XML with XPath in Java
提问by Mg.
I have a XML with a structure similar to this:
我有一个结构与此类似的 XML：
<category>
<subCategoryList>
<category>
</category>
<category>
<!--and so on -->
</category>
</subCategoryList>
</category>
I have a Category class that has a subcategorylist (List<Category>). I'm trying to parse this XML file with XPath, but I can't get the child categories of a category.
我有一个包含subcategory列表 ( List<Category>)的 Category 类。我正在尝试使用 XPath 解析此 XML 文件，但无法获取某个类别的子类别。
How can I do this with XPath? Is there a better way to do this?
我怎样才能用 XPath 做到这一点？有一个更好的方法吗？
采纳答案by ripper234
This linkhas everything you need. In shorts:
这个链接有你需要的一切。简而言之：
public static void main(String[] args)
throws ParserConfigurationException, SAXException,
IOException, XPathExpressionException {
DocumentBuilderFactory domFactory =
DocumentBuilderFactory.newInstance();
domFactory.setNamespaceAware(true);
DocumentBuilder builder = domFactory.newDocumentBuilder();
Document doc = builder.parse("persons.xml");
XPath xpath = XPathFactory.newInstance().newXPath();
// XPath Query for showing all nodes value
XPathExpression expr = xpath.compile("//person/*/text()");
Object result = expr.evaluate(doc, XPathConstants.NODESET);
NodeList nodes = (NodeList) result;
for (int i = 0; i < nodes.getLength(); i++) {
System.out.println(nodes.item(i).getNodeValue());
}
}
回答by sblundy
I believe the XPath expression for this would be "//category/subCategoryList/category". If you just want the children of the root categorynode (assuming it is the document root node), try "/category/subCategoryList/category".
我相信这个 XPath 表达式将是“ //category/subCategoryList/category”。如果您只想要根节点的子category节点（假设它是文档根节点），请尝试“ /category/subCategoryList/category”。
回答by kgiannakakis
This will work for you:
这对你有用：
NodeList nodes = (NodeList) xpath.evaluate("//category//subCategoryList/category",
inputSource, XPathConstants.NODESET);
Then you can parse the children of category as you wish.
然后，您可以根据需要解析类别的子项。
