diff --git a/app/src/main/java/de/hbrs/adenia_sensor_app/FileStreamer.java b/app/src/main/java/de/hbrs/adenia_sensor_app/FileStreamer.java
index c35550fc77004d544b9d34feb8372994de41ce55..d20f9beca3133d54ad445eef3ea62427c1f571df 100644
--- a/app/src/main/java/de/hbrs/adenia_sensor_app/FileStreamer.java
+++ b/app/src/main/java/de/hbrs/adenia_sensor_app/FileStreamer.java
@@ -38,10 +38,9 @@ public class FileStreamer {
         }
 
         // aktuelle Zeit im gewünschten Format auslesen
-        String timeHeader = "";
+        String timeHeader;
         Date date = new Date();
-        SimpleDateFormat format = new SimpleDateFormat(
-                "yyyy-MM-dd_HH:mm:ss.SSS");
+        SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd_HH:mm:ss.SSS", Locale.US);
         timeHeader = MainActivity.getUserID() + ", " + writerId + ", " + format.format(date) + "\n";
 
 
diff --git a/app/src/main/java/de/hbrs/adenia_sensor_app/JsonParser.java b/app/src/main/java/de/hbrs/adenia_sensor_app/JsonParser.java
index 31d09959f62537b19f75ca3df1842dfbffe5a79b..7f3a72fe4c2601ad26919ebcfc77a613f30b92d8 100644
--- a/app/src/main/java/de/hbrs/adenia_sensor_app/JsonParser.java
+++ b/app/src/main/java/de/hbrs/adenia_sensor_app/JsonParser.java
@@ -18,10 +18,6 @@ import java.net.URL;
 import java.net.URLEncoder;
 import java.util.HashMap;
 
-/**
- * Created by rajesh on 19/9/17.
- */
-
 public class JsonParser {
 
     String TAG = "Json Parser";
@@ -62,7 +58,7 @@ public class JsonParser {
                 for (String key : files.keySet()) {
                     int bytesRead, bytesAvailable, bufferSize;
                     byte[] buffer;
-                    int maxBufferSize = 1 * 1024 * 1024;
+                    int maxBufferSize = 1024 * 1024;
 
                     File selectedFile = new File(files.get(key));
                     if (!selectedFile.isFile()) {
diff --git a/app/src/main/java/de/hbrs/adenia_sensor_app/MainActivity.java b/app/src/main/java/de/hbrs/adenia_sensor_app/MainActivity.java
index 7f4c496a4e77318fd721e2be1c650e9e5785e309..52263f1989411a9c13efdf71d0778413f4c63697 100644
--- a/app/src/main/java/de/hbrs/adenia_sensor_app/MainActivity.java
+++ b/app/src/main/java/de/hbrs/adenia_sensor_app/MainActivity.java
@@ -1,5 +1,6 @@
 package de.hbrs.adenia_sensor_app;
 
+import androidx.annotation.NonNull;
 import androidx.appcompat.app.AlertDialog;
 import androidx.appcompat.app.AppCompatActivity;
 import androidx.core.app.ActivityCompat;
@@ -138,7 +139,7 @@ public class MainActivity extends AppCompatActivity {
                             .setPositiveButton(R.string.yes, new DialogInterface.OnClickListener() {
                                 public void onClick(DialogInterface dialog, int id) {
                                     //  Aktion bei Ja: löschen des Datenpfades und starten der Aufnahme
-                                    deleteDir(new File(myPrefs.getString("datapath", "")));
+                                    cleanUp(new File(myPrefs.getString("datapath", "")));
 
                                     startService();
                                     startRecording();
@@ -296,23 +297,25 @@ public class MainActivity extends AppCompatActivity {
         Log.v("Filelöschen", dir.getAbsolutePath());
         File[] files = dir.listFiles();
         if (files != null) {
-            for (int i = 0; i < files.length; i++) {
+            for (File file : files) {
                 Log.v("Filelöschen", "Daten gefunden");
-                if (files[i].isDirectory()) {
-                    deleteDir(files[i]); // Verzeichnis leeren und anschließend löschen
-                }
-                else {
-                    files[i].delete(); // Datei löschen
+                if (file.isDirectory()) {
+                    deleteDir(file); // Verzeichnis leeren und anschließend löschen
+                } else {
+                    Log.v("Datei gelöscht", Boolean.toString(file.delete())); // Datei löschen
                 }
             }
-            dir.delete(); // Ordner löschen
-            Log.v("Filelöschen", "Ordner gelöscht");
+            Log.v("Datei gelöscht", Boolean.toString(dir.delete())); // Ordner löschen
         }
+    }
+
+    public void cleanUp(File dir){
+        deleteDir(dir);
         realPath = null;
         SharedPreferences.Editor editor = myPrefs.edit();
         editor.putString("datapath", realPath);
         editor.apply();
-        showToast("Datapath deleted!!!");
+        showToast("Datapath deleted!");
     }
 
     // View zu Einstellungen wechseln
@@ -521,11 +524,6 @@ public class MainActivity extends AppCompatActivity {
         return String.format(Locale.GERMAN, "%02d:%02d:%02d", hours, mins, secs);
     }
 
-    //  Statusabfrage des Flugmodus
-    private static boolean isAirplaneModeOn(Context context) {
-        return Settings.System.getInt(context.getContentResolver(), Settings.Global.AIRPLANE_MODE_ON, 0) != 0;
-    }
-
     // getter Methoden für Werte aus den SharedPreferences
     public static boolean getPressureAvailable() {
         return pressure;
@@ -589,6 +587,7 @@ public class MainActivity extends AppCompatActivity {
             } else {
                 mLabelInterfaceTime.setText(R.string.data_send);
                 bt_send.setEnabled(false);
+                deleteDir(new File(selectedFilePath));
             }
         }
     }
@@ -603,7 +602,7 @@ public class MainActivity extends AppCompatActivity {
     }
 
     @Override //Override from ActivityCompat.OnRequestPermissionsResultCallback Interface
-    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
+    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
         super.onRequestPermissionsResult(requestCode, permissions, grantResults);
         switch (requestCode) {
             case 1: {
@@ -611,7 +610,6 @@ public class MainActivity extends AppCompatActivity {
                 if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                     // permission granted
                 }
-                return;
             }
         }
     }