BarCode, QRCode&Scan

o build.gradle(app)

implementation 'com.google.zxing:core:3.3.2'

   implementation 'com.journeyapps:zxing-android-embedded:3.5.0'

o BarCode.java 

public class BarCode {

    private static final int WHITE = 0xFFFFFFFF;    // 배경 색상
    private static final int BLACK = 0xFF000000;    // 바코드 색상

    public static Bitmap encodeAsBitmap(String contents, BarcodeFormat format, int img_width, int img_height)
            throws WriterException {

        String contentsToEncode = contents;
        if (contentsToEncode == null) {
            return null;
        }

        Map<EncodeHintType, Object> hints = null;
        String encoding = guessAppropriateEncoding(contentsToEncode);
        if (encoding != null) {
            hints = new EnumMap<EncodeHintType, Object>(EncodeHintType.class);
            hints.put(EncodeHintType.CHARACTER_SET, encoding);
        }

        MultiFormatWriter writer = new MultiFormatWriter();
        BitMatrix result;
        try {
            result = writer.encode(contentsToEncode, format, img_width, img_height, hints);
        } catch (IllegalArgumentException iae) {
            // Unsupported format
            return null;
        }

        int width = result.getWidth();
        int height = result.getHeight();
        int[] pixels = new int[width * height];
        for (int y = 0; y < height; y++) {
            int offset = y * width;
            for (int x = 0; x < width; x++) {
                pixels[offset + x] = result.get(x, y) ? BLACK : WHITE;
            }
        }

        Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
        bitmap.setPixels(pixels, 0, width, 0, 0, width, height);

        return bitmap;
    }

    private static String guessAppropriateEncoding(CharSequence contents) {
        // Very crude at the moment
        for (int i = 0; i < contents.length(); i++) {
            if (contents.charAt(i) > 0xFF) {
                return "UTF-8";
            }
        }
        return null;
    }

}

o QRCode.java

public class QrCode {

    public static Bitmap generateQRCode(String contents) {
        Bitmap bitmap = null;

        try {
            QRCodeWriter qrCodeWriter = new QRCodeWriter();
            bitmap = toBitmap(qrCodeWriter.encode(contents, BarcodeFormat.QR_CODE, 600, 600));
        } catch (WriterException e) {
            e.printStackTrace();
        }

        return bitmap;
    }

    private static Bitmap toBitmap(BitMatrix matrix) {
        int height = matrix.getHeight();
        int width = matrix.getWidth();
        Bitmap bmp = Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565);
        for (int x = 0; x < width; x++) {
            for (int y = 0; y < height; y++) {
                bmp.setPixel(x, y, matrix.get(x, y) ? Color.BLACK : Color.WHITE);
            }
        }
        return bmp;
    }

}

o  MainActivity.java

public class MainActivity extends AppCompatActivity {
    private static final String TAG = MainActivity.class.getSimpleName();

    private ImageView barcode;
    private ImageView qrcode;
    private Button scan;
    private TextView mResult;

    private IntentIntegrator integrator;


    @TargetApi(Build.VERSION_CODES.P)
    @RequiresApi(api = Build.VERSION_CODES.M)
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        barcode = findViewById(R.id.barcode);
        qrcode  = findViewById(R.id.qrcode);
        mResult = findViewById(R.id.result);

        scan = findViewById(R.id.scan);
        scan.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                integrator = new IntentIntegrator(MainActivity.this);
//                integrator.setPrompt("scanning..");
                integrator.setCaptureActivity(CodeCaptureActivity.class);
                integrator.setOrientationLocked(false);
                integrator.initiateScan();
            }
        });

        genBarCode();
        genQrCode();

    }


    private void genBarCode(){
        String barcode_data = "1234567890";

        // barcode image
        try {
            Bitmap bitmap = BarCode.encodeAsBitmap(barcode_data , BarcodeFormat.CODE_128 , 800 , 300);
            barcode.setImageBitmap(bitmap);
        } catch (WriterException e) {
            e.printStackTrace();
        }
    }

    private void genQrCode(){
        String data = "1234567890";

        Bitmap bitmap = QrCode.generateQRCode(data);
        qrcode.setImageBitmap(bitmap);
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
//        super.onActivityResult(requestCode, resultCode, data);
        IntentResult result = IntentIntegrator.parseActivityResult(requestCode, resultCode, data);
        if (result != null) {
            //qrcode 가 없으면
            if (result.getContents() == null) {
                Toast.makeText(MainActivity.this, "취소!", Toast.LENGTH_SHORT).show();
            } else {
                //qrcode 결과가 있으면
                Toast.makeText(MainActivity.this, "스캔완료!", Toast.LENGTH_SHORT).show();
                mResult.setText(result.getContents());
            }

        } else {
            super.onActivityResult(requestCode, resultCode, data);
        }
    }