[Java]Parsing XML Data with DOM

Java解析xml或rss的方法有好幾種
這邊紀錄一下透過javax.xml和org.w3c.dom將xml轉換成DOM tree

範例用xml：

<?xml version="1.0" encoding="UTF-8"?>
<channel>
	<title>佛祖球球</title>
	<link>http://google.com</link>
	<description>佛祖球球焦點新聞</description>
	<generator>Codeigniter</generator>
   	<item>
		<title><![CDATA[佛祖球球出名了]]></title>
		<link>http://google.com/article/517.html</link>
		<creator>行政部</creator>
		<pubDate>Tue, 03 Jul 2012 00:00:01 +0800</pubDate>
		<description><![CDATA[內文內文]]></description>
		<category></category>
	</item>
</channel>

Java：

import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.DocumentBuilder;
import org.w3c.dom.Document;
import org.w3c.dom.NodeList;
import org.w3c.dom.Node;
import org.w3c.dom.Element;

public class ParseXML {
	public static void main(String argv[]) {
		try {
			//定義XML DOM parser解析器
			DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
			//建立DOM document
			DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
			//引入xml
			Document doc = dBuilder.parse("http://test.com/test/test.xml");
			//針對xml文檔的元素做normalize
			doc.getDocumentElement().normalize();

			//XML根節點
			System.out.println("Root Element :" + doc.getDocumentElement().getNodeName());

			//取得所有item元素
			NodeList nList = doc.getElementsByTagName("item");
			for (int temp = 0; temp < nList.getLength(); temp++) {
				//取得該item裡的元素
				Node nNode = nList.item(temp);
				if (nNode.getNodeType() == Node.ELEMENT_NODE) {
					Element eElement = (Element) nNode;
					System.out.println("Title : " + getTagValue("title", eElement));
					System.out.println("Link : " + getTagValue("link", eElement));
					System.out.println("Creator : " + getTagValue("creator", eElement));
				}
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
	//取得元素的值(過濾掉cdata-section等標記)
	private static String getTagValue(String sTag, Element eElement) {
		NodeList nlList = eElement.getElementsByTagName(sTag).item(0).getChildNodes();
		Node nValue = (Node) nlList.item(0);
		return nValue.getNodeValue();
	}

}