Question

in my app when i click a button, i want to show an xml file which is been stored in a database of an url, how to do this, pls give me an example.

Answer 1

Have a server side script get the data on the server and return it as XML. Then download the page and load it into your application.

Using this code you can get an xml file from an online database and parse it as a xml Document in Android.

Document xmlDocument = fromString(downloadPage("http://example.com/data.php");

This is a short script that should download a webpage and return it as a string

public String downloadPage(String targetUrl)
{
    BufferedReader in = null;
    try
    {
        // Create a URL for the desired page
        URL url = new URL(targetUrl);

        // Read all the text returned by the server
        in = new BufferedReader(new InputStreamReader(url.openStream()));
        String str;
        String output = "";
        while ((str = in.readLine()) != null)
        {
            // str is one line of text; readLine() strips the newline
            // character(s)
            output += "\n";
            output += str;
        }
        return output.substring(1);
    }
    catch (MalformedURLException e)
    {}
    catch (IOException e)
    {}
    finally
    {
        try
        {
            if (in != null) in.close();
        }
        catch (IOException e)
        {

        }
    }
    return null;
}

This is a simple DOM parser to parse a string into a Document object.

public static Document fromString(String xml)
{
    if (xml == null)
        throw new NullPointerException("The xml string passed in is null");

    // from http://www.rgagnon.com/javadetails/java-0573.html
    try
    {
        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
        DocumentBuilder db = dbf.newDocumentBuilder();
        InputSource is = new InputSource();
        is.setCharacterStream(new StringReader(xml));

        Document doc = db.parse(is);

        return doc;
    }
    catch (SAXException e)
    {
        return null;
    }
    catch(Exception e)
    {
        CustomExceptionHandler han = new CustomExceptionHandler();
        han.uncaughtException(Thread.currentThread(), e);
        return null;
    }
}