مشکل با پروژه downloader

یعنی کسی جواب این سوال رو نمیدونه. لطفا اگر کسی نظری داره بگه

کدهای به صورت زیره لطفا بگید مشکل از کجاست

کدهای مربوط به کلاس G

public class G extends Application {
  public static Context context;
  public static  final String DIR_SDCRD= Environment.getExternalStorageDirectory().getAbsolutePath();
  public static  final String DIR_APP=DIR_SDCRD+"/file-downloader";
  public static final int DOWNLOAD_BUFFER_SIZE=8*1024;
  public  static final Handler HANDLER=new Handler();

  @Override
  public void onCreate() {
    super.onCreate();
    new File(DIR_APP).mkdirs();
    context=getApplicationContext();
  }
}

کدهای مربوط به کلاس Filedownloader

public class FileDownloader {
  public static  void download(final String downloadPath, final String filePath, final OnProgressDownloadListener listener){

    Thread thread =new Thread(new Runnable() {
      @Override
      public void run() {

        try {
          URL url=new URL(downloadPath);
          HttpURLConnection connection=(HttpURLConnection) url.openConnection();
          connection.setRequestMethod("GET");
          connection.setDoOutput(true);
          connection.connect();

          final int filesize=connection.getContentLength();

          File file=new File(filePath);
          if(file.exists()){
            file.delete();
          }
          FileOutputStream outputStream=new FileOutputStream(filePath);

          InputStream inputStream=connection.getInputStream();
          byte[] buffer=new byte[G.DOWNLOAD_BUFFER_SIZE];
          int len=0;
          int downloadSize=0;
          while((len=inputStream.read(buffer))>0){
            outputStream.write(buffer,0,len);
            downloadSize+=len;
            final  int finaldownloadSize=downloadSize;
            final float downloadPercent=(float) downloadSize/filesize;
            Log.i("Log","downloadsize="+downloadSize+", filesize="+filesize+",percent="+downloadPercent);

            if (listener!=null){
              G.HANDLER.post(new Runnable() {
                @Override
                public void run() {
                listener.OnProgressDownload((int) downloadPercent , finaldownloadSize , filesize);
                }
              });
            }
          }
          outputStream.close();

        } catch (MalformedURLException e) {
          e.printStackTrace();
        }catch (IOException e) {
          e.printStackTrace();
        }
      }
    });
    thread.start();

  }
}

کدهای مربوط به کلاس Main

public class MainActivity extends AppCompatActivity {

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

    Button btnDownload=(Button) findViewById(R.id.btnDownload);
    final TextView txtDownload=(TextView) findViewById(R.id.txtDownload);
    final ProgressBar prgDownload=(ProgressBar) findViewById(R.id.prgDownload);

    btnDownload.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View v) {
        OnProgressDownloadListener listener=new OnProgressDownloadListener() {

          private String convertByteToMB(int byteLength){
            float sizeInKB=(float) byteLength/1024;
            float sizeInMb=(float) sizeInKB/1024;
            return String.format("%.1fMB",sizeInMb);
          }
          @Override
          public void OnProgressDownload(int percent, int downloadSize, int fileSize) {
            prgDownload.setProgress(percent);
            txtDownload.setText(percent+"%"+convertByteToMB(downloadSize)+"/"+convertByteToMB(fileSize));
            //Log.i("Log",""+percent);

          }
        };

      FileDownloader.download("http:/192.168.1.105/file-server/image-4.png", G.DIR_APP + "/sample-image.png" , listener);

      }
    });

  }
}