I have a ProgressDialog which is shown below: package shc_BalloonSat.namespace; import java.io.BufferedReader; import java.io.InputStream;

Question

0

Asked: May 31, 20262026-05-31T07:52:45+00:00 2026-05-31T07:52:45+00:00

I have a ProgressDialog which is shown below: package shc_BalloonSat.namespace; import java.io.BufferedReader; import java.io.InputStream;

0

I have a ProgressDialog which is shown below:

package shc_BalloonSat.namespace;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import android.app.ProgressDialog;
import android.util.Log;

public class httpAPI
{
    Shc_BalloonSat_Activity shc;
    HttpClient client;
    ArrayList<NameValuePair> nameValuePairs;
    HttpResponse response;
    HttpEntity entity;
    InputStream is;
    String result = "";
    HttpPost httppost;
    Thread thread;
    private ProgressDialog progressDialog;

 public httpAPI(Shc_BalloonSat_Activity aContext)
 {
    System.out.println("in the constructor");
        shc = aContext;
 }

public String getData() throws Exception
{
    try
    {
    client = new DefaultHttpClient();
    nameValuePairs = new ArrayList<NameValuePair>();
    httppost = new HttpPost(shc.pref.getString(shc.lastpacketsPHP, shc.lastpacketsPHP.toString()));
    httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
    response = client.execute(httppost);
    entity = response.getEntity();
    is = entity.getContent();
    }

    catch (Exception e)
    {
    Log.e("log_tag", "Error in HTTP connection: " + e.toString());
    }

    try
    {
    BufferedReader reader = new BufferedReader(new InputStreamReader(is,"iso-8859-1"),8);
        StringBuilder sb = new StringBuilder();
        String line = null;

        while ((line = reader.readLine()) != null)
        {
                sb.append(line + "\n");
        }

        is.close();

        result = sb.toString();
    }

    catch(Exception e)
    {
        Log.e("log_tag", "Error converting result: " + e.toString());
    }

    return result;
}

public void runDialog()
{             
    while (thread.isAlive())
    {
    ProgressDialog.show(shc, "Please wait...", "Retrieving data...");
    try
        {
        thread = new Thread(getData());
        thread.start();
        }

    catch (Exception e)
        {
        // TODO Auto-generated catch block
        e.printStackTrace();
        }
    }

}

}

On load the app pulls the information from the server and displays it to the user. This can sometimes take a long time depending on how fast the phone is which is why I added the thread. I also added a ProgressDialog as shown in the code. I’m calling all of this from my main class file as shown below. However for some reason, it doesn’t want to display the ProgressDialog.

package shc_BalloonSat.namespace;

import java.text.DecimalFormat;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.net.ConnectivityManager;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.SubMenu;
import android.widget.TextView;
import android.widget.Toast;

public class Shc_BalloonSat_Activity extends Activity
{
    int historyCountFromUser;
    httpAPI api;
    mapAPI map;
    DecimalFormat df = new DecimalFormat("##.#####");
    DecimalFormat decimalf = new DecimalFormat("##.######");
    AlertDialog alert;
    SharedPreferences pref;
    Editor prefEditor;
    String lastpacketsPHP;


// User to determine how many packet the user would like to see.
int userDefinedCount = 5;

/*
 *  Called when the activity is first created. 
*/

@Override
public void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    loadApp();
}

public boolean isNetworkConnected(Context context)
{
    ConnectivityManager connectionManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
    if (connectionManager.getActiveNetworkInfo() != null && connectionManager.getActiveNetworkInfo().isAvailable() && connectionManager.getActiveNetworkInfo().isConnected())
    {
        return true;
    }

    else 
    {
        return false;
    }
}

public void showAlert()
{
    alert.setTitle("Sorry!");
    alert.setMessage("Please connect to the internet to access the full functionality of this app.");
    alert.setButton("OK", new DialogInterface.OnClickListener()
    {
        public void onClick(DialogInterface dialog, int which)
        {

        }
    });
    alert.show();
}

public void onResume()
{
    super.onResume();
    loadApp();
}

public void onRestart()
{
    super.onRestart();
    loadApp();
}

public void loadApp()
{
    setContentView(shc_BalloonSat.namespace.R.layout.main);
    alert = new AlertDialog.Builder(this).create();
    String returned = "";
    lastpacketsPHP = "";
    pref = getSharedPreferences("shared_prefs", 0);
    prefEditor = pref.edit();
    prefEditor.putString(lastpacketsPHP, "http://space.uah.edu/balloonsat_app/get_last_5_BS_packets.php");
    prefEditor.commit();

    // These next two lines are used to test the PHP files on the SHC server by determining if PHP is set up correctly.
    //prefEditor.putString(lastpacketsPHP, "http://www.wktechnologies.com/shc_android_app/get_last_5_BS_packets.php");
    //prefEditor.commit();   

    if (!isNetworkConnected(this))
    {
    showAlert();
    }

    else
    {
    api = new httpAPI(this);
        map = new mapAPI(this);

        try
        {
            returned = api.getData();
        }

    catch (Exception e)
    {
        Toast.makeText(this, "Error: Unable to receive data at this time.", Toast.LENGTH_SHORT).show();
    }

        TextView infoTV = (TextView)this.findViewById(shc_BalloonSat.namespace.R.id.info);
    infoTV.setText(returned);
    assignInfoToInfoTextView();
    assignInfoToHistoryTextView();
    }
}

@Override
public boolean onCreateOptionsMenu(Menu menu)
{
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(shc_BalloonSat.namespace.R.menu.mainmenu, menu);

    SubMenu submenu = menu.addSubMenu(0, Menu.FIRST, Menu.NONE, "Preferences");
    submenu.add(0, 5, Menu.NONE, "Get Last 5 Packets");
    submenu.add(0, 10, Menu.NONE, "Get Last 10 Packets");
    submenu.add(0, 20, Menu.NONE, "Get Last 20 Packets");
    inflater.inflate(shc_BalloonSat.namespace.R.menu.mainmenu, submenu);

    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item)
{
    // Handle item selection
    switch (item.getItemId())
    {
        case shc_BalloonSat.namespace.R.id.viewKML:
            viewKML();
            return true;
        case 5:
            viewLast5Packets();
            return true;
        case 10:
            viewLast10Packets();
            return true;
        case 20:
            viewLast20Packets();
            return true;
        default:
            return super.onOptionsItemSelected(item);
    }
}

public void assignInfoToInfoTextView()
{
    TextView infoTV = (TextView)this.findViewById(shc_BalloonSat.namespace.R.id.info);
    infoTV.setText("");

    try
    {
            api.runDialog();
        String result = api.result.substring(1, api.result.length()-2);
        JSONObject json_data = new JSONObject(result);

    double altitudeData = json_data.getDouble("altitude");
    double altitudeInFeet = altitudeData * 3.281;
    String infoText = "Last Known Altitude: " + df.format(altitudeInFeet) + " ft\n";

    Double speedData = json_data.optDouble("speed");

    if (speedData.isNaN())
    {
        speedData = 0.00;
    }

    Double direction = json_data.optDouble("heading");
    String directionUnits = " degrees from N";
        String directionText = "";

        if (direction == 0)
        {
            directionText = ", N";
        }
        else if (direction > 0 && direction < 45)
        {
            directionText = ", N NE";
        }

        else if (direction == 45)
        {
            directionText = ", NE";
        }

        else if (direction > 45 && direction < 90)
        {
            directionText = ", E NE";
        }

        else if (direction == 90)
        {
            directionText = ", E";
        }

        else if (direction > 90 && direction < 135)
        {
            directionText = ", E SE";
        }

        else if (direction == 135)
        {
            directionText = ", SE";
        }

        else if (direction > 135 && direction < 180)
        {
            directionText = ", S SE";
        }

        else if (direction == 180)
        {
            directionText = ", S";
        }

        else if (direction > 180 && direction < 225)
        {
            directionText = ", S SW";
        }

        else if (direction == 225)
        {
            directionText = ", SW";
        }

        else if (direction > 225 && direction < 270)
        {
            directionText = ", W SW";
        }

        else if (direction == 270)
        {
            directionText = ", W";
        }

        else if (direction > 270 && direction < 315)
        {
            directionText = ", W NW";
        }

        else if (direction == 315)
        {
            directionText = ", NW";
        }

        else if (direction > 315 && direction < 360)
        {
            directionText = ", N NW";
        }

        else if (direction.isNaN())
        {
        directionText = " Invalid direction";
        }

        else
            {

            }

        infoText += "Last Known Velocity: " + df.format(speedData) + " m/s " + direction + directionUnits + directionText + "\n";

    double recentLatitudeData = json_data.getDouble("latitude");
    infoText += "Last Known Latitude: " + df.format(recentLatitudeData) + "\n";

    double recentLongitudeData = json_data.getDouble("longitude");
    infoText += "Last Known Longtitude: " + df.format(recentLongitudeData) + "\n";

    infoTV.setText(infoText);
    }

    catch (JSONException e)
    {
        // TODO Auto-generated catch block
        Log.e("<tag>", e.getMessage());
        Toast.makeText(this,"Error in (Last Known) method!",Toast.LENGTH_SHORT).show();
    }
    catch (Exception e)
    {
        Log.e("<tag>", e.getMessage());
        Toast.makeText(this,"Error in (Last Known) method!",Toast.LENGTH_SHORT).show();
    }
}

public void assignInfoToHistoryTextView()
{
    try
    {
        api.getData();
        JSONArray jArray = new JSONArray(api.result);
        TextView historyTV = (TextView)this.findViewById(shc_BalloonSat.namespace.R.id.history);
        historyTV.setText("");

        for (int count = 1; count < userDefinedCount; count++)
        {
                JSONObject json_data = jArray.getJSONObject(count);

                double altitudeData = json_data.getDouble("altitude");
                double altitudeInFeet = altitudeData * 3.281;
                String historyText = "Altitude: " + decimalf.format(altitudeInFeet) + " ft\n";

                Double speedData = json_data.optDouble("speed");

                if (speedData.isNaN())
                {
                    speedData = 0.00;
                }

                    Double direction = json_data.optDouble("heading");
                    String directionUnits = " degrees from N";
            String directionText = "";

            if (direction == 0)
            {
                directionText = ", N";
            }
            else if (direction > 0 && direction < 45)
            {
                directionText = ", N NE";
            }

            else if (direction == 45)
            {
                directionText = ", NE";
            }

            else if (direction > 45 && direction < 90)
            {
                directionText = ", E NE";
            }

            else if (direction == 90)
            {
                directionText = ", E";
            }

            else if (direction > 90 && direction < 135)
            {
                directionText = ", E SE";
            }

            else if (direction == 135)
            {
                directionText = ", SE";
            }

            else if (direction > 135 && direction < 180)
            {
                directionText = ", S SE";
            }

            else if (direction == 180)
            {
                directionText = ", S";
            }

            else if (direction > 180 && direction < 225)
            {
                directionText = ", S SW";
            }

            else if (direction == 225)
            {
                directionText = ", SW";
            }

            else if (direction > 225 && direction < 270)
            {
                directionText = ", W SW";
            }

            else if (direction == 270)
            {
                directionText = ", W";
            }

            else if (direction > 270 && direction < 315)
            {
                directionText = ", W NW";
            }

            else if (direction == 315)
            {
                directionText = ", NW";
            }

            else if (direction > 315 && direction < 360)
            {
                directionText = ", N NW";
            }

            else if (direction.isNaN())
            {
                directionText = " Invalid direction";
            }

            else
            {

            }

            if (direction.isNaN())
            {
                historyText += "Velocity: " + df.format(speedData) + " m/s " + directionText + "\n";
            }

            else
            {
                historyText += "Velocity: " + df.format(speedData) + " m/s,\n" + direction + directionUnits + directionText + "\n";
            }

                double latitudeData = json_data.getDouble("latitude");
                historyText += "Latitude: " + df.format(latitudeData) + "\n";

                double longitudeData = json_data.getDouble("longitude");
                historyText += "Longtitude: " + df.format(longitudeData) + "\n\n";

                historyTV.append(historyText);
        }
    }

    catch (JSONException e)
    {
        // TODO Auto-generated catch block
        Log.e("log_tag", "Error parsing data: " + e.toString());
    }
    catch(Exception e)
    {
        Log.e("log_tag", "Error parsing data: " + e.toString());
    }

}

void viewLast5Packets()
{
    if (!isNetworkConnected(this))
    {
        showAlert();
    }

    else
    {
        userDefinedCount = 5;
        prefEditor.putString(lastpacketsPHP, "http://space.uah.edu/balloonsat_app/get_last_5_BS_packets.php");
        prefEditor.commit();
        assignInfoToInfoTextView();
        assignInfoToHistoryTextView();
    }
}

void viewLast10Packets()
{
    if (!isNetworkConnected(this))
    {
        showAlert();
    }

    else
    {
        userDefinedCount = 10;
        prefEditor.putString(lastpacketsPHP, "http://space.uah.edu/balloonsat_app/get_last_10_BS_packets.php");
        prefEditor.commit();
        assignInfoToInfoTextView();
        assignInfoToHistoryTextView();
    }
}

void viewLast20Packets()
{
    if (!isNetworkConnected(this))
    {
        showAlert();
    }

    else
    {
        userDefinedCount = 20;
        prefEditor.putString(lastpacketsPHP, "http://space.uah.edu/balloonsat_app/get_last_20_BS_packets.php");
        prefEditor.commit();
        assignInfoToInfoTextView();
        assignInfoToHistoryTextView();
    }
}

public void viewKML()
{
    if (!isNetworkConnected(this))
    {
        showAlert();
    }

    else
    {
        map.openKML();
    }
 }
}

Any ideas on what I could be doing wrong?

Report

Leave an answer
Cancel reply

You must login to add an answer.

Need An Account,

1 Answer

Editorial Team · Answer 1 · 2026-05-31T07:52:47+00:00

Editorial Team

2026-05-31T07:52:47+00:00Added an answer on May 31, 2026 at 7:52 am

public void runDialog() {           
    Thread thread = null;
    while (thread.isAlive()) // You access null value here
    ...
}

Secondly, you call your loadApp() method from onCreate(..), onResume() and onRestart() methods, which is potentially erratic and obviously redundant. You should call it from one of these methods.

0

Reply
Share
Share

- Report

Sign Up

Sign In

Forgot Password

The Archive Base Latest Questions

I have a ProgressDialog which is shown below: package shc_BalloonSat.namespace; import java.io.BufferedReader; import java.io.InputStream;

Leave an answerCancel reply

1 Answer

Leave an answer
Cancel reply