在Android客户端中使用WCF数据服务

Question

I am a beginner in Android development. I am trying to retrieve data through WCF data service. The service is configured to return data in both atom and json format.

I am using odata4j library. My code is below...

public class Welcome extends Activity {

Button call;
ListView list;
ArrayList categories;
ArrayAdapter adapter;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_welcome);

    setTitle("WCF Example");
    call = (Button) findViewById (R.id.mybtn);
    list = (ListView) findViewById(R.id.mylistview);
    categories = new ArrayList();
    call.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View arg0) {

            new callService().execute();
        }
    });
}
public class callService extends AsyncTask<Void, Void, ArrayList<String>> {
    @Override
    protected ArrayList<String> doInBackground(Void... params) {

    ODataConsumer c =                    ODataJerseyConsumer.create("http://217.37.219.177:82/EbosDataService.svc");
        List<OEntity> listEntities = c.getEntities("driver_details").execute().toList();
        System.out.println("Size"+ listEntities.size());
        if (listEntities.size() > 0) {
            for (OEntity entity : listEntities) {
                categories.add(entity.getProperty("DriverID").getValue().toString()
                        + " - "
                        + entity.getProperty("DriverFirstName").getValue());
            }
        }
        return categories;
    }
    @Override
    protected void onPostExecute(ArrayList<String> result) {            
        super.onPostExecute(result);
        adapter = new ArrayAdapter<String>(Welcome.this,
                android.R.layout.simple_list_item_1, result);
        list.setAdapter(adapter);
    }
}
}

When I run, the application become unresponsive. Please see the log

http://217.37.219.177:85/errorlog.txt

However when I access http://services.odata.org/Northwind/Northwind.svc my code works. Please see the log

http://217.37.219.177:85/successlog.txt

I guess there is something wrong with my service. I cannot work out the issue as I am using the same service in different dot net client and it works fine.

Any help will be much appreciated.

Thanks.

Answer 1

I would suggest you debugging the app to solve NullPointerException.

by the way, you are using OData earlier version. if you use OData V4 on server side, then on the client side, you can use Apache Olingo OData for Java Client @ http://olingo.apache.org/doc/odata4/download.html Olingo OData Client for Android Download (md5, sha512, pgp)