java基础 读取XML文件数据

读取language.xml

<pre name="code" class="java"><span style="font-size:18px;"><?xml version="1.0" encoding="UTF-8"?>
<Languages cat="it">
	<lan id="1">
		<name>Java</name>
		<ide>Eclipse</ide>
	</lan>
	<lan id="2">
		<name>Swift</name>
		<ide>Xcode</ide>
	</lan>
	<lan id="3">
		<name>C#</name>
		<ide>Visual Studio</ide>
	</lan>
</Languages></span>

测试代码如下：

<strong><span style="font-size:18px;">package com.demo;

import java.io.File;
import java.io.IOException;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

public class readxml {

	public static void main(String[] args) 
	{
		try {
			DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
			DocumentBuilder builder = factory.newDocumentBuilder();
			Document document = builder.parse(new File("languages.xml"));
			
			//获得根节点
			Element root =  document.getDocumentElement();
			System.out.println("cat = " + root.getAttribute("cat"));
			NodeList list = root.getElementsByTagName("lan");
			for (int i = 0; i < list.getLength(); i++) {
				Element lan = (Element) list.item(i);
				System.out.println("---------------------");
				System.out.println("id = " + lan.getAttribute("id"));
				
				//这样的方法getElementsByTagName（）返回的是nodelist还需要取第一个值item（0），这种做法不好
//				Element name = (Element) lan.getElementsByTagName("name").item(0);
//				System.out.println("name = " + name.getTextContent());
//				Element ide = (Element) lan.getElementsByTagName("ide").item(0);
//				System.out.println("ide = " + ide.getTextContent());
				
				//由每一个父节点获取到相应所有子节点，再循环取值
				NodeList clist = lan.getChildNodes();
				for (int j = 0; j < clist.getLength(); j++) {
					Node node = clist.item(j);
					//在读取xml文件时<>与<>中间的空白部分也会被识别出来，因此通过一判断是否为元素而排出空白部分
					//不理解的话可以试着把判断删掉。就会把空白部分以text=  的形式打印出来
					if (node instanceof Element) {
						System.out.println(node.getNodeName() + " = " + node.getTextContent());
					}
				}
			}
			
		} catch (ParserConfigurationException e) {
			e.printStackTrace();
		} catch (SAXException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}
			
	}

}</span></strong>

运行结果如下
cat = it
---------------------
id = 1
name = Java
ide = Eclipse
---------------------
id = 2
name = Swift
ide = Xcode
---------------------
id = 3
name = C#
ide = Visual Studio