htmlparser解析网页基本代码

import javax.swing.JOptionPane;

import org.htmlparser.Node;
import org.htmlparser.NodeFilter;
import org.htmlparser.Parser;
import org.htmlparser.filters.NodeClassFilter;
import org.htmlparser.filters.OrFilter;
import org.htmlparser.lexer.Page;
import org.htmlparser.tags.ImageTag;
import org.htmlparser.tags.LinkTag;
import org.htmlparser.util.NodeList;
import org.htmlparser.util.ParserException;
import org.htmlparser.util.SimpleNodeIterator;

public class HPDemo { 
	    // 循环访问所有节点，输出包含关键字的值节点
		public static void extractKeyWordText(String url, String keyword) {
			try {
	            //生成一个解析器对象，用网页的 url 作为参数
				Parser parser = new Parser(url);
				//设置网页的编码,这里只是请求了一个 gb2312 编码网页
				parser.setEncoding("UTF-8");
				//迭代所有节点, null 表示不使用 NodeFilter
				NodeList list = parser.parse(null);
	            //从初始的节点列表跌倒所有的节点
				processNodeList(list, keyword);
			} catch (ParserException e) {
				e.printStackTrace();
			}
		}

		private static void processNodeList(NodeList list, String keyword) {
			//迭代开始
			SimpleNodeIterator iterator = list.elements();
			while (iterator.hasMoreNodes()) {
				Node node = iterator.nextNode();
				//得到该节点的子节点列表
				NodeList childList = node.getChildren();
				//孩子节点为空，说明是值节点
				if (null == childList)
				{
					//得到值节点的值
					String result = node.toPlainTextString();
					//若包含关键字，则简单打印出来文本
					if (result.indexOf(keyword) != -1){
						System.out.println(result);
					}
				} //end if
				//孩子节点不为空，继续迭代该孩子节点
				else 
				{
					processNodeList(childList, keyword);
				}//end else
			}//end wile
		}
		
		// 获取一个网页上所有的链接和图片链接
		public static void extracLinks(String url) {
			try {
				Parser parser = new Parser(url);
				parser.setEncoding("gb2312");
	//过滤 <frame> 标签的 filter，用来提取 frame 标签里的 src 属性所、表示的链接
				NodeFilter frameFilter = new NodeFilter() {
					public boolean accept(Node node) {
						if (node.getText().startsWith("frame src=")) {
							return true;
						} else {return false;}
					}
				};
			
	     //OrFilter 来设置过滤 <a> 标签，<img> 标签和 <frame> 标签，三个标签是 or 的关系
		 OrFilter rorFilter = new OrFilter(new NodeClassFilter(LinkTag.class), new NodeClassFilter(ImageTag.class));
		 OrFilter linkFilter = new OrFilter(rorFilter, frameFilter);
		//得到所有经过过滤的标签
		NodeList list = parser.extractAllNodesThatMatch(linkFilter);
		for (int i = 0; i < list.size(); i++) {
			Node tag = list.elementAt(i);
			if (tag instanceof LinkTag)//<a> 标签 
			{
				LinkTag link = (LinkTag) tag;
				String linkUrl = link.getLink();//url
				String text = link.getLinkText();//链接文字
				System.out.println(linkUrl + "**********" + text);
			}
			else if (tag instanceof ImageTag)//<img> 标签
			{
				ImageTag image = (ImageTag) list.elementAt(i);
				System.out.print(image.getImageURL() + "********");//图片地址
				System.out.println(image.getText());//图片文字
			}
			else//<frame> 标签
			{
				//提取 frame 里 src 属性的链接如 <frame src="test.html"/>
				String frame = tag.getText();
				int start = frame.indexOf("src=");
				frame = frame.substring(start);
				int end = frame.indexOf(" ");
				if (end == -1)
					end = frame.indexOf(">");
				frame = frame.substring(5, end - 1);
				System.out.println(frame);
			}
		}
	} catch (ParserException e) {e.printStackTrace();}
	}
		
		public static void main(String args[]) {
			
			String gUrl = null;
			String gKey = null;
			if (0 >= args.length)
	        {
	        String  strurl = (String)JOptionPane.showInputDialog (
	                null,
	                "Enter the URL to capture:",
	                "Web Site",
	                JOptionPane.PLAIN_MESSAGE,
	                null,
	                null,
	                "http://guangzhou.qfang.com/sale/6749835");
	            if (null != strurl)
	            	gUrl=strurl;
	            else
	                System.exit (1);
	        }else gUrl=args[0];
			
	        if (1 >= args.length)
	        {
	        String  strKey = (String)JOptionPane.showInputDialog (
	                null,
	                "Enter the keywords to capture:",
	                "Key words",
	                JOptionPane.PLAIN_MESSAGE,
	                null,
	                null,
	                "总价");
	            if (null != strKey)
	            	gKey=strKey;
	            else
	                System.exit (1);
	        }else gKey=args[1];
	            
			//extractKeyWordText(gUrl,gKey);
			extracLinks(gUrl);
			
			System.exit (0);
		}
}