JVAV xpath 辅助工具

import java.io.File;
import java.io.InputStream;
 
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpressionException;
import javax.xml.xpath.XPathFactory;
 
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
 
/**
 *

 * xpath辅助类
 * @version 1.0
 */
public class XMLUtil
{
    javax.xml.xpath.XPath oXpath;
    /**
     * 构造xml文档对应的document对象
     * @param file
     * @return
     * @throws Exception
     */
    public Document parseFile(File file) throws Exception
    {
        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
        dbf.setValidating(false);
        DocumentBuilder db = dbf.newDocumentBuilder();
        org.w3c.dom.Document doc = db.parse(file);
 
        // 创建XPath对象
        XPathFactory factory = XPathFactory.newInstance();
        oXpath = factory.newXPath();
        return doc;
    }
    /**
     * 构造输入流对应的document对象
     * @param in
     * @return
     * @throws Exception
     */
    public Document parseStream(InputStream in) throws Exception
    {
        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
        dbf.setValidating(false);
        DocumentBuilder db = dbf.newDocumentBuilder();
        org.w3c.dom.Document doc = db.parse(in);
 
        // 创建XPath对象
        XPathFactory factory = XPathFactory.newInstance();
        oXpath = factory.newXPath();
        return doc;
    }
    /**
     * 获取结点值
     * @param node
     * @return
     */
    public String getNodeValue(Node node)
    {
        String dataValue = node.getTextContent();
        return dataValue;
    }
    /**
     * 获取结点List
     * @param node
     * @param xpath
     * @return
     * @throws XPathExpressionException
     */
    public NodeList getNodeList(org.w3c.dom.Node node, String xpath) throws XPathExpressionException
    {
        NodeList nodeList = (NodeList) oXpath.evaluate(xpath, node, XPathConstants.NODESET);
 
        return nodeList;
    }
    /**
     * 获取单个结点
     * @param node
     * @param xpath
     * @return
     * @throws XPathExpressionException
     */
    public Node getNode(org.w3c.dom.Node node, String xpath) throws XPathExpressionException
    {
        Node nodeRet = (Node) oXpath.evaluate(xpath, node, XPathConstants.NODE);
 
        return nodeRet;
    }
}

如果涉及W3C和dom4j Document对象 之间的转换，可参考：https://blog.csdn.net/lijun169/article/details/82585218