在android app client上从python服务器接收值，然后从mysql显示与该值相对应的数据

Question

I'm getting to receive data from Python server on android client, and i'm storing the data in a variable called Answerfromserver. After that I'm using the Answerfromserver to retrieve data from wamp database. Now when i install the app on my phone, what happens is that when i get the correct data for retrieval from wamp, so my app crashes. I'm attaching my app code, please help me on this..

Edit - I commented out the execute of the code where the data is received from the mysql wamp server, so in that case my app is correctly displaying the data from python server, but i comment out the execute of the python server code app crashes..

package marecki.androidsocketclient;

    import android.content.Context;
    import android.os.AsyncTask;
    import android.support.v7.app.AlertDialog;
    import android.support.v7.app.AppCompatActivity;
    import android.os.Bundle;
    import android.util.Log;
    import android.view.View;
    import android.widget.ProgressBar;
    import android.widget.TextView;
    import android.widget.Button;
    import android.widget.EditText;
    import android.view.View.OnClickListener;
    import android.widget.Toast;

    import java.io.BufferedReader;
    import java.io.BufferedWriter;
    import java.io.ByteArrayOutputStream;
    import java.io.DataInputStream;
    import java.io.DataOutputStream;
    import java.io.IOException;
    import java.io.InputStream;
    import java.io.InputStreamReader;
    import java.io.OutputStream;
    import java.io.OutputStreamWriter;
    import java.net.HttpURLConnection;
    import java.net.MalformedURLException;
    import java.net.Socket;
    import java.net.URL;
    import java.net.URLEncoder;
    import java.net.UnknownHostException;

    import static java.io.DataInputStream.readUTF;

    public class MainActivity extends AppCompatActivity {

        TextView textAnswer;
        Button buttonConnect;
        EditText editTextIP, editTextPort, message;
        ProgressBar progressBar;
        String result="";

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

            textAnswer = (TextView)findViewById(R.id.text_answer);
            buttonConnect = (Button)findViewById(R.id.connect);
            editTextIP = (EditText)findViewById(R.id.address);
            editTextPort = (EditText)findViewById(R.id.port);
            message = (EditText)findViewById(R.id.edit_message);

           progressBar = (ProgressBar)findViewById((R.id.progressBar));
           progressBar.setVisibility(ProgressBar.INVISIBLE);

            buttonConnect.setOnClickListener(buttonConnectOnClickListener);
        }

        OnClickListener buttonConnectOnClickListener = new OnClickListener() {

            @Override
            public void onClick(View arg0) {

                String Msg = message.getText().toString();

                ClientTask clientTask = new ClientTask(
                                                editTextIP.getText().toString(),
                                                Integer.parseInt(editTextPort
                                                                .getText().toString()),
                                                Msg);
                clientTask.execute();
            }
        };
        public class ClientTask extends AsyncTask <Void, Void, Void> {

            String IPaddress;
            int portAddress;
            String AnswerFromServer ="";
            String msgToServer;

            ClientTask(String address, int port, String msgToServ){
                IPaddress = address;
                portAddress = port;
                msgToServer = msgToServ;
            }

            @Override
            protected void onPreExecute() {
                progressBar.setVisibility(ProgressBar.VISIBLE);
            }

            @Override
            protected Void doInBackground(Void... arg0) {

                Socket socket = null;
                DataOutputStream dataOutputStream = null;
                DataInputStream dataInputStream = null;

                try {
                    socket = new Socket(IPaddress,portAddress);

                    dataOutputStream = new DataOutputStream(
                                                socket.getOutputStream());
                    BufferedReader br = new BufferedReader(
                                                new InputStreamReader(socket.getInputStream()));
                   // dataInputStream = new DataInputStream(
                   //                           socket.getInputStream());

                    if(msgToServer != null){
                        dataOutputStream.writeUTF(msgToServer);
                    }

                    AnswerFromServer = br.readLine();

                    String password = "123";
                    String type = "login";
                    BackgroundWorker backgroundWorker = 
                                new BackgroundWorker(MainActivity.this);
                    backgroundWorker.execute(type, AnswerFromServer, password);


                }catch (UnknownHostException e) {
                    e.printStackTrace();
                    AnswerFromServer = e.toString();
                }catch (IOException e) {
                    e.printStackTrace();
                    AnswerFromServer = e.toString();
                }finally {
                    if(socket != null){
                        try{
                            socket.close();
                        }catch (IOException e){
                            e.printStackTrace();
                        }
                    }
                }

                if(dataOutputStream != null){
                    try{
                        dataOutputStream.close();
                    }catch (IOException e){
                        e.printStackTrace();
                    }
                }

                if(dataInputStream != null){
                    try{
                        dataInputStream.close();
                    }catch (IOException e){
                        e.printStackTrace();
                    }
                }

                return null;

            }

            @Override
            protected void onPostExecute(Void aVoid) {
                progressBar.setVisibility(ProgressBar.INVISIBLE);
                textAnswer.setText(AnswerFromServer);
                Toast.makeText(MainActivity.this,result,Toast.LENGTH_LONG);
                super.onPostExecute(aVoid);
            }
        }

        public class BackgroundWorker extends AsyncTask<String,Void,String>
        {
            Context context;
            AlertDialog alertDialog;
            BackgroundWorker (Context ctx)
            {

            }

            @Override
            protected String doInBackground(String... params) {
                String type = params[0];
                String login_url="http;//192.168.8.103/login.php";
                if (type.equals("login"))
                {
                    try
                    {
                        String user_name = params[1];
                        String password = params[2];
                        URL url = new URL(login_url);
                        HttpURLConnection httpURLConnection = (HttpURLConnection)url.openConnection();
                        httpURLConnection.setRequestMethod("POST");
                        httpURLConnection.setDoOutput(true);
                        httpURLConnection.setDoInput(true);
                        OutputStream outputStream = httpURLConnection.getOutputStream();
                        BufferedWriter bufferedWriter = 
                                        new BufferedWriter(new OutputStreamWriter(outputStream,"UTF-8"));
                        String post_data = 
                                        URLEncoder.encode("user_name","UTF-8")
                                                            +"="
                                                            + URLEncoder.encode(user_name,"UTF-8")
                                                            +"&"
                        +URLEncoder.encode("password","UTF-8")+"="+ URLEncoder.encode(password,"UTF-8");
                        bufferedWriter.write(post_data);
                        bufferedWriter.flush();
                        outputStream.close();
                        InputStream inputStream = httpURLConnection.getInputStream();
                        BufferedReader bufferedReader = 
                                        new BufferedReader(new InputStreamReader(inputStream, "iso-8859-1"));
                        String result="";
                        String line="";
                        while ((line=bufferedReader.readLine())!=null)
                        {
                            result+=line;

                        }
                        bufferedReader.close();
                        inputStream.close();
                        httpURLConnection.disconnect();
                        return  result;





                    }
                    catch (MalformedURLException e)
                    {
                        e.printStackTrace();

                    }
                    catch (IOException e)
                    {
                        e.printStackTrace();

                    }
                }
                return null;
            }

            @Override
            protected void onPreExecute() {
                alertDialog = new AlertDialog.Builder(context).create();
                alertDialog.setTitle("Login Status");
            }

            @Override
            protected void onPostExecute(String result) {
                alertDialog.setMessage(result);
                alertDialog.show();
            }

        }

    }