来自HTTP的XML解析文件

Question

I have an XML file located at a location such as

http://example.com/test.xml

I'm trying to parse the XML file to use it in my program with xPath like this but it is not working.

Document doc = builder.parse(new File(url));

How can I get the XML file?

Answer 1

Try using URLConnection.getInputStream() for getting the handle of XML file.

See the below code, in that I am trying to open an xml file and printing all the description fields:

import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;

import org.w3c.dom.Document;
import org.w3c.dom.NodeList;

public class HTTPXMLTest
{
    public static void main(String[] args) 
    {
        try {
            new HTTPXMLTest().start();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private void start() throws Exception
    {
        URL url = new URL("http://localhost:8080/AutoLogin/resource/web.xml");
        URLConnection connection = url.openConnection();

        Document doc = parseXML(connection.getInputStream());
        NodeList descNodes = doc.getElementsByTagName("description");

        for(int i=0; i<descNodes.getLength();i++)
        {
            System.out.println(descNodes.item(i).getTextContent());
        }
    }

    private Document parseXML(InputStream stream)
    throws Exception
    {
        DocumentBuilderFactory objDocumentBuilderFactory = null;
        DocumentBuilder objDocumentBuilder = null;
        Document doc = null;
        try
        {
            objDocumentBuilderFactory = DocumentBuilderFactory.newInstance();
            objDocumentBuilder = objDocumentBuilderFactory.newDocumentBuilder();

            doc = objDocumentBuilder.parse(stream);
        }
        catch(Exception ex)
        {
            throw ex;
        }       

        return doc;
    }
}

Answer 2

Here is the simple example for getting data form this string " http://www.gettingagile.com/feed/rss2/ "

public class MainClassXml {

    public static void main(String args[]) throws URISyntaxException,
            ClientProtocolException, IOException, MalformedURLException {

        String url = "http://www.gettingagile.com/feed/rss2/";
        System.out.println("Url is careated****");
        URL url2 = new URL(url);
        HttpGet httpGet = new HttpGet(url);
        HttpClient httpClient = new DefaultHttpClient();

        HttpResponse httpResponse = httpClient.execute(httpGet);
        HttpEntity entity = httpResponse.getEntity();
        System.out.println("Entity is*****" + entity);
        try {
            String xmlParseString = EntityUtils.toString(entity);
            System.out.println("This Stirng to be Pasrse***" + xmlParseString);

            HttpURLConnection connection = (HttpURLConnection) url2
                    .openConnection();
            InputStream inputStream = connection.getInputStream();

            DocumentBuilderFactory builderFactory = DocumentBuilderFactory
                    .newInstance();
            DocumentBuilder documentBuilder = builderFactory
                    .newDocumentBuilder();
            Document document = documentBuilder.parse(inputStream);
            document.getDocumentElement().normalize();

            System.out.println("Attributes are***" + document.getAttributes());

            NodeList nodeList = document.getElementsByTagName("rss");
            System.out.println("This is firstnode" + nodeList);
            for (int getChild = 0; getChild < nodeList.getLength(); getChild++) {

                Node Listnode = nodeList.item(getChild);
                System.out.println("Into the for loop"
                        + Listnode.getAttributes().getLength());
                Element firstnoderss = (Element) Listnode;
                System.out.println("ListNodes" + Listnode.getAttributes());
                System.out.println("This is node list length"
                        + nodeList.getLength());

                Node Subnode = nodeList.item(getChild);
                System.out.println("This is list node" + Subnode);
                System.out.println("rss attributes***************");
            }

        } catch (Exception exception) {

            System.out.println("Exception is" + exception);

        }
    }

Answer 3

摆脱new File() ：

Document doc = builder.parse(url);

Answer 4

A little more detail, based on laz answer:

String urlString = "http://example.com/test.xml";
URL url = new URL(urlString);
Document doc = builder.parse(url);

Answer 5

It's much easier with a XMLPullParser ... you don't have to deal with this event stuff and can quickly pick up some keywords ... I'm using it too ... only a couple of code lines :)

http://developer.android.com/reference/org/xmlpull/v1/XmlPullParser.html

Regarding HTTP and files have a look here Download a file with DefaultHTTPClient and preemptive authentication

Answer 6

File fileXml = new File(url);

DocumentBuilder parser = DocumentBuilderFactory.newInstance().newDocumentBuilder();
Document document = parser.parse(fileXml);

it should go