Parsing a JSON Response from a .Net webservice

Question

Just to get this out in the open I am new to JAVA, KSOAP, and JSON. So I'll try to explain this the best I can.

A while ago I created a webservice to be consumed by Blackberry Apps that we're built using the plug in for Visual Studio. Now the project I am working on, I want to consume the same webservice for Android devices. For the most part I have the base code for the Android app done and working. Here's my problem:

I can successfully call the webservice and get a response. I know from creating the webservice that it sends a JSON response. My problem is trying to parse through the JSON response. I have found a few examples that I have been suiting to my needs however I am hung up on one thing.

In the JSON each element is preceeded by "anyType" which is forcing my code to return no results (Ultimately I am binding the data to an ArrayList) Here's what I get if I "getProperty(0).toString()...

anyType{Artist=anyType{TrackName=Champagne Supernova;};

Here is the code I am using to parse the JSON Object....

SoapObject gr = (SoapObject)envelope.getResponse();
        String ro = gr.getProperty(0).toString();
              //Added just to see structure of response
        Artist_Result.add(gr.toString());

        if (ro.startsWith("{"))
        {
            JSONObject JSONObj = new JSONObject(ro);
            Iterator<String> itr = JSONObj.keys();
            while (itr.hasNext())
            {
                String key = (String)itr.next();
                String value = JSONObj.getString(key);
                //bundleResult.putString(key, value);
                Artist_Result.add(value);
            }

        }
        else if (ro.startsWith("["))
        {
            JSONArr = new JSONArray(ro);
            for (int i = 0; i < JSONArr.length(); i++)
            {
                JSONObj = (JSONObject)JSONArr.get(i);
                //bundleResult.putString(String.valueOf(i), JSONObj.toString());
                Artist_Result.add(JSONObj.toString());
            }
        }

WebService Code:

 [WebMethod]
[return: System.Xml.Serialization.XmlArrayItemAttribute(typeof(Artist))]
public Artist[] GetArtist(string ArtistQuery)
{
   // All the SQL Stuff Here

    SqlDataReader sReader;
    sReader = cmd.ExecuteReader();

    List<Artist> Artists = new List<Artist>();
    while (sReader.Read())
    {
        Artist result = new Artist();
        result.TrackName = sReader.GetString(0);

        Artists.Add(result);
    }
    sReader.Close();
    sqlConn.Close();

    return Artists.ToArray();
}

public class Artist
{
    public string TrackName;
}

Sample of XML Output from a browser:

<?xml version="1.0" encoding="utf-8" ?> 
- <ArrayOfArtist xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns="http://bb.mcrcog.com/"&gt;
    - <Artist>
          <TrackName>Champagne Supernova</TrackName> 
      </Artist>
    - <Artist>
         <TrackName>Don't Look Back In Anger</TrackName> 
      </Artist>
    - <Artist>
          <TrackName>D'you Know What I Mean</TrackName> 
      </Artist>
    - <Artist>
          <TrackName>Go Let It Out</TrackName> 
      </Artist>

I have a feeling I will need to implement a Class, and Getters/Setters on the Android side. I'm just not sure how to go about doing that. Any help would be greatly appreciated!

Answer 1

Looks like you're using the org.json package. I suggest you use the net.sf.json package at http://json-lib.sourceforge.net/ It contains a lot more functionality and you can create a JSONObject or JSONArray from a string (or other objects like Map) with no effort with JSONObject.fromObject(obj) (similar for JSONArrays).

Answer 2

After playing around I finally got a solution. Although I'm not exactly happy with it, this does display the results in a desireable format in my app. Just want to figure out how to get the child properties direct without manipulating the strings...

try
    {
        HttpTransportSE at = new HttpTransportSE(URL);
        at.setXmlVersionTag("<?xml version=\"1.0\" encoding=\"UTF-8\"?>");
        at.call(SOAP_ACTION, envelope);

        SoapObject gr = (SoapObject)envelope.getResponse();
        for(int i = 0; i < gr.getPropertyCount(); i++ )
        {
            String start = gr.getProperty(i).toString();
            int left = 18;
            int iosc = start.indexOf(";");
            String end = start.substring(left, iosc);
            Artist_Result.add(end);
        }
    }