public class CameraActivity extends AppCompatActivity
{
    private static final int PERMISSION_REQUEST_CODE = 1;
    ImageView pic;
    Button capture;
    Uri file;

    @Override
    protected void onCreate(Bundle b)
    {
        super.onCreate(b);
        setContentView(R.layout.cameralayout);
        capture = findViewById(R.id.cameratpicture);
        pic = findViewById(R.id.picture);
        if (Build.VERSION.SDK_INT >= 23)
        {
            if (checkPermission())
            {
                Log.e("permission", "Permission already granted.");
            }
            else
            {
                requestPermission();
            }
        }
        capture.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (checkPermission()){
                    takePicture();
                }
                else{
                    Toast.makeText(getApplicationContext(),"Permission denied",Toast.LENGTH_SHORT).show();
                }

            }
        });
    }
    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) {
                pic.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");
    }
    private boolean checkPermission()
    {
        int camerapermission = ContextCompat.checkSelfPermission(getApplicationContext(), Manifest.permission.CAMERA);
        int storagepermission = ContextCompat.checkSelfPermission(getApplicationContext(),Manifest.permission.WRITE_EXTERNAL_STORAGE);
        if(camerapermission == PackageManager.PERMISSION_GRANTED && storagepermission == PackageManager.PERMISSION_GRANTED)
        {
            return true;
        }
        else {
            return false;
        }
    }
    private void requestPermission()
    {
        ActivityCompat.requestPermissions(this,new String[]{Manifest.permission.CAMERA,Manifest.permission.WRITE_EXTERNAL_STORAGE},PERMISSION_REQUEST_CODE);
    }
    @Override
    public void onRequestPermissionsResult(int requestCode, String permissions[], int[]grantResults)
    {
        switch(requestCode) {
            case PERMISSION_REQUEST_CODE:
                if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED && grantResults[1] == PackageManager.PERMISSION_GRANTED) {
                    Toast.makeText(getApplicationContext(), "Permission accepted", Toast.LENGTH_SHORT).show();
                }
                else {
                    if (grantResults[0] == PackageManager.PERMISSION_DENIED || grantResults[1] == PackageManager.PERMISSION_DENIED) {
                        Toast.makeText(getApplicationContext(), "Camera or Storage Permission denied", Toast.LENGTH_SHORT).show();
                    }
                    capture.setEnabled(false);
                }
        }
    }
}