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