如何将XML输入流解析为字符串或对象（Android Studio）

Question

Iam new with android and Java. (I can program in C#) and iam trying to retrieve some XML file from the internet and parse it into objects. Iam struggling with it for hours right now. I think it isn't very complicated but i cant find the right way to do it.

Iam started with this but there is a lot of stuff in it i don't need so i tried to write some clean code with only the things i need. I read a lot of articles on the internet but i cant get them working....

I created an default project in android studio with one Activity. I created an subclass in this activity caled XmlManager. This subclass extends the AsyncTask. This are the methods in it:

private class XmlManager extends AsyncTask<String,String,String> {
@Override
protected String doInBackground(String... inputUrl)
{
    Log.i("XML Status", "ASync proces started");
    getStream(inputUrl[0]);
    Log.i("XML Status", "ASync proces finished");
    return null;
}

@Override
protected void onPostExecute(String result)
{
    //Here i want to return the list with objects...
    // OR an string with the XML so i can parse it somewhere else,
    // I dont know what is the best practice
}

private void getStream(String urlString) {

    URL url =null;
    HttpURLConnection urlConnection = null;
    InputStream is = null;

    try {
        url = new URL(urlString);
        Log.i("Status", "Connection opened");
        urlConnection  = (HttpURLConnection) url.openConnection();
        urlConnection.setRequestMethod("GET");
        urlConnection.connect();

        is = urlConnection.getInputStream();
        Log.i("Status", "Streamreader filled");
    }
    catch (Exception e) {
        Log.e("Error",e.getMessage().toString());
    }
    finally {
        if (urlConnection != null) {
            urlConnection.disconnect();
            Log.i("Status","Connection disconnected");
        }
    }
}

Can someone help me please? or have an link to an WORKING and EASY example(i cant find :'( )

I read something about a Simple XML library for parsing XML to objects, is this the way to do it? try to retrieve XML as string or something and then parse it with any library?

Thanks in advance!

Answer 1

you can parse xml to java object by JAXB.

1) you can change xml to xsd by xmlspy.

2) using eclipse plugins( http://sourceforge.net/projects/jaxb-builder/ ) to generate java class .

3) use jaxb to parse xml to java object. the example code like this:

 JAXBContext context = JAXBContext.newInstance(XXXX.class);
 Unmarshaller unmarshaller = context.createUnmarshaller();
 XXXX obj = unmarshaller.unmarshal(is);

XXXX is the second step generate java class.

Answer 2

try to use SitesXmlPullParser from SrackSites here is the link: https://github.com/FoamyGuy/StackSites/blob/master/src/com/makemyandroidapp/example/stacksites/SitesXmlPullParser.java

the idea is to get the tags to every object so that you can choose whatever you want to use and put the items in a list

Answer 3

I have found what i missed. I needed and bufferedReader and an Stringbuilder for making an string from the XML from the website. No i can parse the string into and object with the SimpleXML library. The getStream method what i now use is:

   private void getStream(String urlString) {
        URL url = null;
        HttpURLConnection urlConnection = null;
        InputStream is = null;

        try {
            url = new URL(urlString);

            urlConnection = (HttpURLConnection) url.openConnection();
            urlConnection.setRequestMethod("GET");
            urlConnection.connect();
            Log.i("Status", "Connection opened");

            BufferedReader r = new BufferedReader(new InputStreamReader(urlConnection.getInputStream()));
            StringBuilder total = new StringBuilder();
            String line;
            while ((line = r.readLine()) != null) {
                total.append(line);
            }
            Log.i("Status", "XML loaded into string");

        } catch (Exception e) {
            Log.e("Error", e.getMessage().toString());
        } finally {
            if (urlConnection != null) {
                urlConnection.disconnect();
                Log.i("Status", "Connection disconnected");
            }
        }
    }

The string "total" contains the XML code. Thanks for the help anyway.