java使用xpath解析xml示例分享

XPath即为XML路径语言（XML Path Language），它是一种用来确定XML文档中某部分位置的语言。XPath基于XML的树状结构，提供在数据结构树中找寻节点的能力。起初 XPath 的提出的初衷是将其作为一个通用的、介于XPointer与XSL间的语法模型。但是 XPath 很快的被开发者采用来当作小型查询语言。

XPathTest.java
复制代码 代码如下:
package com.hongyuan.test;

import java.io.File;
import java.io.IOException;

import javax.xml.parsers.documentBuilder;
import javax.xml.parsers.documentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.xpath.XPath;
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;
import org.xml.sax.SAXException;

public class XPathTest {

 public static void main(String[] args) throws ParserConfigurationException,
   SAXException, IOException, XPathexpressionException {

  // 解析文件，生成document对象
  documentBuilder builder = documentBuilderFactory.newInstance()
    .newdocumentBuilder();
  document document = builder.parse(new File("bookstore.xml"));

  // 生成XPath对象
  XPath xpath = XPathFactory.newInstance().newXPath();

  // 获取节点值
  String webTitle = (String) xpath.evaluate(
    "/bookstore/book[@category='WEB']/title/text()", document,
    XPathConstants.STRING);
  System.out.println(webTitle);

  System.out.println("===========================================================");

  // 获取节点属性值
  String webTitleLang = (String) xpath.evaluate(
    "/bookstore/book[@category='WEB']/title/@lang", document,
    XPathConstants.STRING);
  System.out.println(webTitleLang);

  System.out.println("===========================================================");

  // 获取节点对象
  Node bookWeb = (Node) xpath.evaluate(
    "/bookstore/book[@category='WEB']", document,
    XPathConstants.NODE);
  System.out.println(bookWeb.getNodeName());

  System.out.println("===========================================================");

  // 获取节点集合
  NodeList books = (NodeList) xpath.evaluate("/bookstore/book", document,
    XPathConstants.NODESET);
  for (int i = 0; i < books.getLength(); i++) {
   Node book = books.item(i);
   System.out.println(xpath.evaluate("@category", book,
     XPathConstants.STRING));
  }

  System.out.println("===========================================================");
 }

}

bookstore.xml
复制代码 代码如下:


 
  
   Giada De Laurentiis
   2005
   30.00
 
 
  
   J K. Rowling
   2005
   29.99
 
 
  
   Erik T. Ray
   2003
   39.95
 



运行效果