Java如何使用xpath表达式查询xml节点文本
使用Java进行XPath查询XML节点文本可以借助于Java内置的XML解析器和XPath表达式。以下是一个XML样例和Java代码示例：
XML样例：
<root>
<book>
<title>Java编程</title>
<author>John Doe</author>
<year>2019</year>
</book>
<book>
<title>Python入门</title>
<author>Jane Smith</author>
<year>2018</year>
</book>
</root>
Java样例代码：
import javax.xml.parsers.DocumentBuilderFactory;
import org.w3c.dom.Document;
import org.w3c.dom.NodeList;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpression;
import javax.xml.xpath.XPathExpressionException;
import javax.xml.xpath.XPathFactory;
public class XPathExample {
public static void main(String[] args) {
try {
// 创建XML文档解析器
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
Document doc = factory.newDocumentBuilder().parse("path_to_xml_file"); // 将xml文件路径替换为实际的路径
// 创建XPath对象
XPath xpath = XPathFactory.newInstance().newXPath();
// 创建XPath表达式
XPathExpression expression = xpath.compile("//book/title/text()");
// 执行XPath表达式并获取结果
NodeList nodeList = (NodeList) expression.evaluate(doc, XPathConstants.NODESET);
// 遍历结果并输出节点文本
for (int i = 0; i < nodeList.getLength(); i++) {
System.out.println(nodeList.item(i).getNodeValue());
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
这个示例中使用了Java的内置XML解析器和XPath支持。可以通过引入以下maven依赖以使用这些类：
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
<version>3.12.0</version>
</dependency>
