diff --git a/samples/android/15-puzzle/src/org/opencv/samples/puzzle15/Puzzle15Activity.java b/samples/android/15-puzzle/src/org/opencv/samples/puzzle15/Puzzle15Activity.java
index df428b570a..45bb51a192 100644
--- a/samples/android/15-puzzle/src/org/opencv/samples/puzzle15/Puzzle15Activity.java
+++ b/samples/android/15-puzzle/src/org/opencv/samples/puzzle15/Puzzle15Activity.java
@@ -19,7 +19,7 @@ import android.view.WindowManager;
 
 public class Puzzle15Activity extends Activity implements CvCameraViewListener, View.OnTouchListener {
 
-    private static final String  TAG = "Sample::Puzzle15::Activity";
+    private static final String  TAG = "Puzzle15::Activity";
 
     private CameraBridgeViewBase mOpenCvCameraView;
     private Puzzle15Processor    mPuzzle15;
diff --git a/samples/android/camera-calibration/src/org/opencv/samples/cameracalibration/CalibrationResult.java b/samples/android/camera-calibration/src/org/opencv/samples/cameracalibration/CalibrationResult.java
index 4b03d5967a..a4c77e4cdf 100644
--- a/samples/android/camera-calibration/src/org/opencv/samples/cameracalibration/CalibrationResult.java
+++ b/samples/android/camera-calibration/src/org/opencv/samples/cameracalibration/CalibrationResult.java
@@ -8,7 +8,7 @@ import android.content.SharedPreferences;
 import android.util.Log;
 
 public abstract class CalibrationResult {
-    private static final String TAG = "OCVSample::CalibrationResult";
+    private static final String TAG = "OCV::CalibrationResult";
 
     private static final int CAMERA_MATRIX_ROWS = 3;
     private static final int CAMERA_MATRIX_COLS = 3;
@@ -22,19 +22,19 @@ public abstract class CalibrationResult {
         cameraMatrix.get(0,  0, cameraMatrixArray);
         for (int i = 0; i < CAMERA_MATRIX_ROWS; i++) {
             for (int j = 0; j < CAMERA_MATRIX_COLS; j++) {
-                Integer id = i * CAMERA_MATRIX_ROWS + j;
-                editor.putFloat(id.toString(), (float)cameraMatrixArray[id]);
+                int id = i * CAMERA_MATRIX_ROWS + j;
+                editor.putFloat(Integer.toString(id), (float)cameraMatrixArray[id]);
             }
         }
 
         double[] distortionCoefficientsArray = new double[DISTORTION_COEFFICIENTS_SIZE];
         distortionCoefficients.get(0, 0, distortionCoefficientsArray);
         int shift = CAMERA_MATRIX_ROWS * CAMERA_MATRIX_COLS;
-        for (Integer i = shift; i < DISTORTION_COEFFICIENTS_SIZE + shift; i++) {
-            editor.putFloat(i.toString(), (float)distortionCoefficientsArray[i-shift]);
+        for (int i = shift; i < DISTORTION_COEFFICIENTS_SIZE + shift; i++) {
+            editor.putFloat(Integer.toString(i), (float)distortionCoefficientsArray[i-shift]);
         }
 
-        editor.commit();
+        editor.apply();
         Log.i(TAG, "Saved camera matrix: " + cameraMatrix.dump());
         Log.i(TAG, "Saved distortion coefficients: " + distortionCoefficients.dump());
     }
@@ -49,8 +49,8 @@ public abstract class CalibrationResult {
         double[] cameraMatrixArray = new double[CAMERA_MATRIX_ROWS * CAMERA_MATRIX_COLS];
         for (int i = 0; i < CAMERA_MATRIX_ROWS; i++) {
             for (int j = 0; j < CAMERA_MATRIX_COLS; j++) {
-                Integer id = i * CAMERA_MATRIX_ROWS + j;
-                cameraMatrixArray[id] = sharedPref.getFloat(id.toString(), -1);
+                int id = i * CAMERA_MATRIX_ROWS + j;
+                cameraMatrixArray[id] = sharedPref.getFloat(Integer.toString(id), -1);
             }
         }
         cameraMatrix.put(0, 0, cameraMatrixArray);
@@ -58,8 +58,8 @@ public abstract class CalibrationResult {
 
         double[] distortionCoefficientsArray = new double[DISTORTION_COEFFICIENTS_SIZE];
         int shift = CAMERA_MATRIX_ROWS * CAMERA_MATRIX_COLS;
-        for (Integer i = shift; i < DISTORTION_COEFFICIENTS_SIZE + shift; i++) {
-            distortionCoefficientsArray[i - shift] = sharedPref.getFloat(i.toString(), -1);
+        for (int i = shift; i < DISTORTION_COEFFICIENTS_SIZE + shift; i++) {
+            distortionCoefficientsArray[i - shift] = sharedPref.getFloat(Integer.toString(i), -1);
         }
         distortionCoefficients.put(0, 0, distortionCoefficientsArray);
         Log.i(TAG, "Loaded distortion coefficients: " + distortionCoefficients.dump());
diff --git a/samples/android/camera-calibration/src/org/opencv/samples/cameracalibration/CameraCalibrator.java b/samples/android/camera-calibration/src/org/opencv/samples/cameracalibration/CameraCalibrator.java
index 47ebeb89f5..6414427511 100644
--- a/samples/android/camera-calibration/src/org/opencv/samples/cameracalibration/CameraCalibrator.java
+++ b/samples/android/camera-calibration/src/org/opencv/samples/cameracalibration/CameraCalibrator.java
@@ -18,7 +18,7 @@ import org.opencv.imgproc.Imgproc;
 import android.util.Log;
 
 public class CameraCalibrator {
-    private static final String TAG = "OCVSample::CameraCalibrator";
+    private static final String TAG = "OCV::CameraCalibrator";
 
     private final Size mPatternSize = new Size(4, 11);
     private final int mCornersSize = (int)(mPatternSize.width * mPatternSize.height);
@@ -81,7 +81,7 @@ public class CameraCalibrator {
 
     private void calcBoardCornerPositions(Mat corners) {
         final int cn = 3;
-        float positions[] = new float[mCornersSize * cn];
+        float[] positions = new float[mCornersSize * cn];
 
         for (int i = 0; i < mPatternSize.height; i++) {
             for (int j = 0; j < mPatternSize.width * cn; j += cn) {
@@ -101,7 +101,7 @@ public class CameraCalibrator {
         MatOfPoint2f cornersProjected = new MatOfPoint2f();
         double totalError = 0;
         double error;
-        float viewErrors[] = new float[objectPoints.size()];
+        float[] viewErrors = new float[objectPoints.size()];
 
         MatOfDouble distortionCoefficients = new MatOfDouble(mDistortionCoefficients);
         int totalPoints = 0;