Date and time added to saved file name.

samples/android/tutorial-5-cameracontrol/src/org/opencv/samples/tutorial5/Sample5CameraControl.java

 package org.opencv.samples.tutorial5;
 
+import java.text.SimpleDateFormat;
+import java.util.Date;
 import java.util.List;
 import java.util.ListIterator;
 
@@ -9,6 +11,7 @@ import org.opencv.android.OpenCVLoader;
 import org.opencv.core.Mat;
 import org.opencv.android.CameraBridgeViewBase.CvCameraViewListener;
 
+import android.annotation.SuppressLint;
 import android.app.Activity;
 import android.os.Bundle;
 import android.os.Environment;
@@ -125,10 +128,14 @@ public class Sample5CameraControl extends Activity implements CvCameraViewListen
         return true;
     }
 
+    @SuppressLint("SimpleDateFormat")
     @Override
     public boolean onTouch(View v, MotionEvent event) {
         Log.i(TAG,"onTouch event");
-        String fileName = Environment.getExternalStorageDirectory().getPath() + "/sample_picture.jpg";
+        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd_HH-mm-ss");
+        String currentDateandTime = sdf.format(new Date());
+        String fileName = Environment.getExternalStorageDirectory().getPath() +
+                               "/sample_picture_" + currentDateandTime + ".jpg";
         mOpenCvCameraView.takePicture(fileName);
         Toast.makeText(this, fileName + " saved", Toast.LENGTH_SHORT).show();
         return false;