mevsungur

//Buffered Image nesnesini Base64 encoded stringe dönüştürmek için
public static String bufferedImgToBase64String(final BufferedImage img, final String formatName) {
        final ByteArrayOutputStream os = new ByteArrayOutputStream();
        try {
            ImageIO.write(img, formatName, Base64.getEncoder().wrap(os));
            return os.toString(StandardCharsets.ISO_8859_1.name());
        } catch (final IOException ioe) {
            throw new UncheckedIOException(ioe);
        }
    }

mevsungur

public static void main(String[] args) {
        BufferedImage qrImage = null;
        try {
            qrImage = createQr("https://medium.com/@mevlutsungur", 150);
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (WriterException e) {
            e.printStackTrace();
        }
        final String fileFormat = "PNG";

mevsungur

public static BufferedImage createQr(String text, Integer length) throws UnsupportedEncodingException, WriterException {

        MultiFormatWriter writer = new MultiFormatWriter();
        text = new String(text.getBytes("UTF-8"),"UTF-8");
        BitMatrix matrix = writer.encode( text,
                BarcodeFormat.QR_CODE, length, length);

        BufferedImage bufferedImage = MatrixToImageWriter.toBufferedImage(matrix);

        return bufferedImage;

mevsungur

<dependency>
    <groupId>com.google.zxing</groupId>
    <artifactId>core</artifactId>
    <version>3.4.1</version>
</dependency>
<dependency>
    <groupId>com.google.zxing</groupId>
    <artifactId>javase</artifactId>
    <version>3.4.1</version>
</dependency>

mevsungur

enum Beden {
        SMALL,MEDIUM,LARGE
}

mevsungur

public static void main(String[] args) {
    LocalDate now = LocalDate.now();
    List<LocalDate> isimList = Arrays.asList(now, null,  now.minusDays(2), now.plusDays(3), 
                                             now.minusMonths(2), null, now.plusYears(1), null);

    isimList.sort(Comparator.nullsLast(LocalDate::compareTo));

    isimList.stream().forEach(System.out::println);
}

mevsungur

public static void main(String[] args) {
    List<String> isimList = Arrays.asList("Sungur",null,"Mevlüt");

    isimList.sort(Comparator.nullsFirst(String::compareTo));

    isimList.stream().forEach(System.out::println);
}

mevsungur

public static void main(String[] args) {
    List<String> isimList = Arrays.asList("Sungur",null,"Mevlüt","Angular");

    isimList = isimList.stream().filter(i -> i != null).sorted(String::compareTo)
                                                    .collect(Collectors.toList());

    isimList.forEach(System.out::println);
}

mevsungur

public static void main(String[] args) {
    List<String> isimList = Arrays.asList("Sungur",null,"Mevlüt","Angular");

    isimList.sort(String::compareTo);
}

mevsungur

    public static void main(String[] args) {
        List<String> isimler = new ArrayList<>() {{
            add("Mevlüt");
            add("Sungur");
            add("Java");
            add("Angular");
        }};
        
        for(String s : isimler) {
            if(s.startsWith("S")) isimler.remove(s);