android - java.lang.NullPointerException

Question

i am new to android programming. i am working on a project in which i have to send images from android to php server. code was working fine until today when i run again the project i am getting these errors. i don't know what's went wrong into my code. please help me

These are the errors

   02-22 23:22:44.117: I/System.out(12070): fileName is null
02-22 23:22:44.117: D/AndroidRuntime(12070): Shutting down VM
02-22 23:22:44.117: W/dalvikvm(12070): threadid=1: thread exiting with uncaught exception (group=0x40018578)
02-22 23:22:44.117: E/AndroidRuntime(12070): FATAL EXCEPTION: main
02-22 23:22:44.117: E/AndroidRuntime(12070): java.lang.NullPointerException
02-22 23:22:44.117: E/AndroidRuntime(12070):    at me.company.backup.MainActivity.upload(MainActivity.java:94)
02-22 23:22:44.117: E/AndroidRuntime(12070):    at me.company.backup.MainActivity$1.onClick(MainActivity.java:58)
02-22 23:22:44.117: E/AndroidRuntime(12070):    at android.view.View.performClick(View.java:2485)
02-22 23:22:44.117: E/AndroidRuntime(12070):    at android.view.View$PerformClick.run(View.java:9080)
02-22 23:22:44.117: E/AndroidRuntime(12070):    at android.os.Handler.handleCallback(Handler.java:587)
02-22 23:22:44.117: E/AndroidRuntime(12070):    at android.os.Handler.dispatchMessage(Handler.java:92)
02-22 23:22:44.117: E/AndroidRuntime(12070):    at android.os.Looper.loop(Looper.java:130)
02-22 23:22:44.117: E/AndroidRuntime(12070):    at android.app.ActivityThread.main(ActivityThread.java:3687)
02-22 23:22:44.117: E/AndroidRuntime(12070):    at java.lang.reflect.Method.invokeNative(Native Method)
02-22 23:22:44.117: E/AndroidRuntime(12070):    at java.lang.reflect.Method.invoke(Method.java:507)
02-22 23:22:44.117: E/AndroidRuntime(12070):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:867)
02-22 23:22:44.117: E/AndroidRuntime(12070):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:625)
02-22 23:22:44.117: E/AndroidRuntime(12070):    at dalvik.system.NativeStart.main(Native Method)

here is my code

 public class MainActivity extends Activity{

Uri currImageURI;
ProgressDialog dialog = null;

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



    Button upload_btn = (Button) this.findViewById(R.id.uploadButton);
    upload_btn.setOnClickListener(new View.OnClickListener() {
        public void onClick(View view) {

            upload();
            }});



}

public void upload(){            

            ArrayList<Uri> fileName = getFileList();
            for ( int i = 0 ; i < fileName.size() ; i++ )
            {
            HttpUploader uploader = new HttpUploader();

            try {

                  uploader.execute(getRealPathFromURI(fileName.get(i))).get();
                  Thread.sleep(1000);   
            } catch (InterruptedException e) {
                  e.printStackTrace();
                } catch (ExecutionException e) {
                  e.printStackTrace();
                }
            }

        }



public String getRealPathFromURI(Uri contentUri) {

    String [] proj={MediaStore.Images.Media.DATA};
    android.database.Cursor cursor = managedQuery( contentUri,
    proj,     // Which columns to return
    null,     // WHERE clause; which rows to return (all rows)
    null,     // WHERE clause selection arguments (none)
    null);     // Order-by clause (ascending by name)
    int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
    cursor.moveToFirst();
    return cursor.getString(column_index);
}



private ArrayList<Uri> getFileList()
{
    ArrayList<Uri> fileList = new ArrayList<Uri>();
    try
    {
        String[] proj = { MediaStore.Images.Media.DATA, MediaStore.Images.Media._ID };
        Cursor actualimagecursor = managedQuery(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, proj,
                null, null, MediaStore.Images.Media.DEFAULT_SORT_ORDER);

        int actual_image_column_index = actualimagecursor.getColumnIndexOrThrow(MediaStore.Images.Media._ID);

        for ( int i = 0 ; i < actualimagecursor.getCount() ; i++ )
        {
            actualimagecursor.moveToPosition(i);
            String fileName = actualimagecursor.getString(actual_image_column_index);
            fileList.add(( Uri.withAppendedPath( MediaStore.Images.Media.EXTERNAL_CONTENT_URI, fileName )));

        }
        return fileList;
    }
    catch ( Exception e )
    {
        return null;
    }
}

httpUploader

public  class HttpUploader extends AsyncTask<String, Void, String> {

 protected String doInBackground(String... path) {

    String outPut = null;

    for (String sdPath:path) {

        Bitmap bitmapOrg = BitmapFactory.decodeFile(sdPath);
        ByteArrayOutputStream bao = new ByteArrayOutputStream();

        //Resize the image
        double width = bitmapOrg.getWidth();
        double height = bitmapOrg.getHeight();
        double ratio = 400/width;
        int newheight = (int)(ratio*height);

       // System.out.println("———-width" + width);
        //System.out.println("———-height" + height);

        bitmapOrg = Bitmap.createScaledBitmap(bitmapOrg, 400, newheight, true);

        //Here you can define .PNG as well
        bitmapOrg.compress(Bitmap.CompressFormat.JPEG, 95, bao);
        byte[] ba = bao.toByteArray();
        String ba1 = Base64.encodeToString(ba, 0);

        //System.out.println("uploading image now ——–" + ba1);

        ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
        nameValuePairs.add(new BasicNameValuePair("image", ba1));

        try {
            HttpClient httpclient = new DefaultHttpClient();
            HttpPost httppost = new HttpPost("http://technolsys.net/imageupload.php");
            httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));

            HttpResponse response = httpclient.execute(httppost);
            HttpEntity entity = response.getEntity();                

            // print responce
            outPut = EntityUtils.toString(entity);
            Log.i("GET RESPONSE—-", outPut);

            //is = entity.getContent();
            Log.e("log_tag ******", "good connection");

            bitmapOrg.recycle();

        } catch (Exception e) {
            Log.e("log_tag ******", "Error in http connection " + e.toString());
        }
    }
    return outPut;
}


}

Answer 1

i figure out the solution. actually there were no data in my sd card (EXTERNAL_CONTENT_URI) so thats why the list was returning null .