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java使用xpath解析xml示例分享

更新時(shí)間：2014年03月23日 09:18:37 作者：

XPath基于XML的樹(shù)狀結(jié)構(gòu)，提供在數(shù)據(jù)結(jié)構(gòu)樹(shù)中找尋節(jié)點(diǎn)的能力，下面是一小示例,需要的朋友可以參考下

XPath即為XML路徑語(yǔ)言（XML Path Language），它是一種用來(lái)確定XML文檔中某部分位置的語(yǔ)言。XPath基于XML的樹(shù)狀結(jié)構(gòu)，提供在數(shù)據(jù)結(jié)構(gòu)樹(shù)中找尋節(jié)點(diǎn)的能力。起初 XPath 的提出的初衷是將其作為一個(gè)通用的、介于XPointer與XSL間的語(yǔ)法模型。但是 XPath 很快的被開(kāi)發(fā)者采用來(lái)當(dāng)作小型查詢(xún)語(yǔ)言。

XPathTest.java

復(fù)制代碼代碼如下:

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對(duì)象
  DocumentBuilder builder = DocumentBuilderFactory.newInstance()
    .newDocumentBuilder();
  Document document = builder.parse(new File("bookstore.xml"));

// 生成XPath對(duì)象
XPath xpath = XPathFactory.newInstance().newXPath();

  // 獲取節(jié)點(diǎn)值
  String webTitle = (String) xpath.evaluate(
    "/bookstore/book[@category='WEB']/title/text()", document,
    XPathConstants.STRING);
  System.out.println(webTitle);

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

  // 獲取節(jié)點(diǎn)屬性值
  String webTitleLang = (String) xpath.evaluate(
    "/bookstore/book[@category='WEB']/title/@lang", document,
    XPathConstants.STRING);
  System.out.println(webTitleLang);

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

  // 獲取節(jié)點(diǎn)對(duì)象
  Node bookWeb = (Node) xpath.evaluate(
    "/bookstore/book[@category='WEB']", document,
    XPathConstants.NODE);
  System.out.println(bookWeb.getNodeName());

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

  // 獲取節(jié)點(diǎn)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

復(fù)制代碼代碼如下:

<?xml version="1.0" encoding="utf-8" ?>
<bookstore>
 <book category="COOKING">
   <title lang="en">Everyday Italian</title> 
   <author>Giada De Laurentiis</author> 
   <year>2005</year> 
   <price>30.00</price> 
 </book>
 <book category="CHILDREN">
   <title lang="en">Harry Potter</title> 
   <author>J K. Rowling</author> 
   <year>2005</year> 
   <price>29.99</price> 
 </book>
 <book category="WEB">
   <title lang="en">Learning XML</title> 
   <author>Erik T. Ray</author> 
   <year>2003</year> 
   <price>39.95</price> 
 </book>
</bookstore>