android.permission.CAMERA
android.permission.WRITE_EXTERNAL_STORAGE


public void takePicture() {
    Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    file = Uri.fromFile(getOutputMediaFile());
    intent.putExtra(MediaStore.EXTRA_OUTPUT, file);

    startActivityForResult(intent, 100);
}

protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == 100) {
        if (resultCode == RESULT_OK) {
            imageView.setImageURI(file);
        }
    }
}

private static File getOutputMediaFile(){
    File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(
            Environment.DIRECTORY_PICTURES), "CameraDemo");

    if (!mediaStorageDir.exists()){
        if (!mediaStorageDir.mkdirs()){
            return null;
        }
    }

    String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
    return new File(mediaStorageDir.getPath() + File.separator +
                "IMG_"+ timeStamp + ".jpg");
}