xml_dom resolve

 DOM parsing (a)
using dom parsed xml document will all loaded into memory, and then converts all of the content node xml document (the object) on the tree.

Advantages:
random parse
can modify the file
you can create xml file
drawbacks:
for small files parsing, high memory requirements

1.1.1 xml respective output key information (using analytical dom)

package xml2;

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.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

public class domTest {
	public static void main(String[] args) throws Exception {
		// 创建工厂
		DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
		DocumentBuilder builder = factory.newDocumentBuilder();
		Document document = builder.parse("src/xml2/desk.xml");
		//
		List = document.getElementsByTagName a NodeList ( "Disk"); 
		for (int I = 0; I <list.getLength (); I ++) { 
			the Node Node = list.item (I); // two disk, by an index can be get any of Disk 
			// Print properties section node node node name, and value, at the same time, there may be multiple attributes, so it is still a collection returned. 
			System.out.println ( 
					.. Node.getAttributes () Item (0) .getNodeName () + ":" + node.getAttributes () Item (0) .getNodeValue ()); 
			a NodeList Node.getChildNodes List2 = (); 
			// because the disk label have child nodes spaces, it has no child nodes, so I do not have to consider this, then, will be a first null pointer exception 
			// solving the problem, then direct node was once sentenced segment type value is 1 (element node) 
			for (int J = 0; J <list2.getLength (); J ++) { 
				IF (list2.item (J) .getNodeType () ==. 1) { 
					System.out.println (list2.item (J). getNodeName () + ":" + list2.item (j) .getTextContent ());

		// Node attributes = node.getAttributes().item(0);
//		System.out.println(attributes);
//		System.out.println(attributes.getNodeName());
//		System.out.println(attributes.getNodeType());
//		System.out.println(attributes.getNodeValue());

	}
}

<?xml version="1.0" encoding="UTF-8"?>
<disks>
	<disk name='c盘'>
		<size>10G</size>
		<directory>100</directory>
		<file>200</file>
	</disk>

	<disk name='d盘'>
		<size>20G</size>
		<directory>200</directory>
		<file>3000</file>
	</disk>
</disks>