Java HTML/XML - 如何检索/提取XML元素属性值

import java.io.FileInputStream;
import java.io.InputStream;

import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpression;
import javax.xml.xpath.XPathFactory;

import org.xml.sax.InputSource;

public class Main {

  public static void main(String[] args) throws Exception {
    InputStream inputStream = new FileInputStream("data.xml");
    InputSource inputSource = new InputSource(inputStream);
    XPath xpath = XPathFactory.newInstance().newXPath();
    XPathExpression expr = xpath.compile("/PaymentElement/Payment/@seqID");
    Object result = expr.evaluate(inputSource, XPathConstants.STRING);
    System.out.println(result);
  }

}