Network Programming in .NET

This may not be the best way to call a Microsoft .NET ASMX webservice via Java for Android, but it seems to work OK for my needs. All you need to do, is call it asynchronously, and handle the data returned.

Here’s my class that I’m using to call the ASMX webservice;

package uk.org.regcheck.regcheck;

import android.os.AsyncTask;

import android.util.Log;

import org.json.JSONObject;
import org.w3c.dom.Document;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;

import java.io.BufferedInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.StringReader;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;

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



public class RegCheckAPI extends AsyncTask<String, String, String> {

    DataDownloadListener dataDownloadListener;
    public static interface DataDownloadListener {
        void dataDownloadedSuccessfully(String data);
        void dataDownloadFailed();
    }


    public void CheckUK(String RegistrationNumber,String username)
    {
        try {
            this.execute("https://www.regcheck.org.uk/api/reg.asmx/Check?" +
                    "&RegistrationNumber=" + URLEncoder.encode(RegistrationNumber, "utf-8") +
                    "&username=" + URLEncoder.encode(username, "utf-8"));
            Log.i(RegistrationNumber, username);
        }
        catch(UnsupportedEncodingException ex){
            Log.i("error",ex.getMessage());
        }
    }

    @Override
    protected String doInBackground(String... uri) {
        String responseString = "";
        try {
            URL url = new URL(uri[0]);
            HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
            InputStream in = new BufferedInputStream(urlConnection.getInputStream());
            responseString = new String(readFully(in), "utf-8");
        }
        catch(IOException ex)
        {
            responseString = ex.toString();
        }
        return responseString;
    }

    private byte[] readFully(InputStream inputStream)
            throws IOException {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        byte[] buffer = new byte[1024];
        int length = 0;
        while ((length = inputStream.read(buffer)) != -1) {
            baos.write(buffer, 0, length);
        }
        return baos.toByteArray();
    }

    @Override
    protected void onPostExecute(String result) {
        if(result != null)
        {
            try {
                DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
                DocumentBuilder builder = factory.newDocumentBuilder();
                Document doc = builder.parse(new InputSource(new StringReader(result)));
                NodeList nJson = doc.getElementsByTagName("vehicleJson");
                String strJson = nJson.item(0).getTextContent();
                JSONObject jObject = new JSONObject(strJson);
                String strDescription = jObject.getString("Description");
                dataDownloadListener.dataDownloadedSuccessfully(strDescription);
            }
            catch(Exception ex)
            {
                dataDownloadListener.dataDownloadFailed();
            }
        }
        else
            dataDownloadListener.dataDownloadFailed();

    }
}

Then my main activity is as follows;

package uk.org.regcheck.regcheck;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

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

TextView t = (TextView)findViewById(R.id.tbOutput);
t.setText(“Please wait…”);

RegCheckAPI api = new RegCheckAPI();
api.dataDownloadListener = (new RegCheckAPI.DataDownloadListener()
{
@SuppressWarnings(“unchecked”)
@Override
public void dataDownloadedSuccessfully(String data) {
TextView t = (TextView)findViewById(R.id.tbOutput);
t.setText(data);
}
@Override
public void dataDownloadFailed() {
// handler failure (e.g network not available etc.)
TextView t = (TextView)findViewById(R.id.tbOutput);
t.setText(“Failed”);
}
});
api.CheckUK(“{{valid UK plate}}”,”{{Your username here}}”);
}
}