Question

我正在尝试使用这段代码来解析放在外部服务器上的XML文件。问题是输出只列出表中的第一个结果。有什么建议为什么会这样？代码非常混乱，我为此道歉。我正在使用此代码作为学校实验来测试通过servlet进行解析，这基本上只是我在网上找到的预制servlet，我正在尝试适应我的项目。

如果有人能够解决我的问题，或想出一个更好的解决方案来解决问题，我将非常感激！

import java.io.*;
import org.w3c.dom.*;
import javax.servlet.*;
import javax.servlet.annotation.WebServlet;
import javax.xml.parsers.*;
import javax.servlet.http.*;

@WebServlet(urlPatterns = {"/Veivesen"})

public class Veivesen extends HttpServlet{ 


    public boolean isTextNode(Node n){
        return n.getNodeName().equals("#text");
    }


    public void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException {
        response.setContentType("text/html");
        PrintWriter out = response.getWriter();

        try{
            DocumentBuilderFactory docFactory =  DocumentBuilderFactory.newInstance();
            DocumentBuilder docBuilder = docFactory.newDocumentBuilder();
            Document doc = docBuilder.parse("http://www.p4.no/rss/trafikk.aspx?area=20");
            out.println("<table border=2><tr><th>Title</th><th>Link</th></tr>");
            Element  element = doc.getDocumentElement(); 
            NodeList newsNodes = element.getChildNodes();
            for (int i=0; i<newsNodes.getLength(); i++){
                Node news = newsNodes.item(i);
                out.println(news);
                if (isTextNode(news))
                    continue;
                NodeList NameDOBCity = news.getChildNodes(); 
                out.println("<tr>");
                for (int j=0; j<NameDOBCity.getLength(); j++ ){
                    Node node = NameDOBCity.item(j);
                    if ( isTextNode(node)) 
                        continue;
                    out.println("<td>"+(node.getFirstChild().getNodeValue())+"</td>");
                    System.out.println(node.getFirstChild());
                } 
                out.println("</tr>");
            }
            out.println("</table>");
        } catch(Exception e) {
            System.out.println(e);
        }
    }
}

Answer 1

如果你要做的是阅读RSS频道中的项目，你需要找到合适的xml元素，试试doGet方法的这个修改版本：

public void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException {

    response.setContentType("text/html");
    PrintWriter out = response.getWriter();

    try {
        DocumentBuilderFactory docFactory =  DocumentBuilderFactory.newInstance();
        DocumentBuilder docBuilder = docFactory.newDocumentBuilder();
        Document doc = docBuilder.parse("http://www.p4.no/rss/trafikk.aspx?area=20");
        out.println("<html><body><table border=2><tr><th>Title</th><th>Link</th></tr>");
        Element element = doc.getDocumentElement();
        NodeList channelNodes = element.getElementsByTagName("channel");
        NodeList newsNodes = ((Element)channelNodes.item(0)).getElementsByTagName("item");

        for (int i=0; i<newsNodes.getLength(); i++){
            Node news = newsNodes.item(i);
            //out.println(news);
            if (isTextNode(news))
                continue;
            NodeList NameDOBCity = news.getChildNodes();
            out.println("<tr>");
            for (int j=0; j<NameDOBCity.getLength(); j++ ){
                Node node = NameDOBCity.item(j);
                if ( isTextNode(node))
                    continue;
                out.println("<td>"+(node.getFirstChild().getNodeValue())+"</td>");
                System.out.println(node.getFirstChild());
            }
            out.println("</tr>");
        }
        out.println("</table></body></html>");
    } catch(Exception e) {
        System.out.println(e);
    }

}

只从Java servlet解析器获取一个元素输出

1 个答案: