Java 二维码生成工具类

public class QRcodeUtils {

    /**
     * 容错率等级 L
     */
    public static final char CORRECT_L = ‘L‘;

    /**
     * 容错率等级 M
     */
    public static final char CORRECT_M = ‘M‘;

    /**
     * 容错率等级 Q
     */
    public static final char CORRECT_Q = ‘Q‘;

    /**
     * 容错率等级 H
     */
    public static final char CORRECT_H = ‘H‘;

    /**
     * 旁白占用比率
     */
    public static final double PADDING_RATIO = 0.05;

    /**
     * 生成二维码
     * @param content 要生成的内容
     * @param size    要生成的尺寸
     * @param versoin 二维码尺寸，取值范围1-40，值越大尺寸越大，可存储的信息越大
     * @param ecc 二维码排错率，可选L(7%)、M(15%)、Q(25%)、H(30%)
     * @return
     * @throws Exception
     */
    public static BufferedImage encode(String content, int size, int version, char ecc, BufferedImage logo) throws Exception{
        BufferedImage image = null;
        Qrcode qrcode = new Qrcode();
        // 设置二维码排错率，可选L(7%)、M(15%)、Q(25%)、H(30%)，排错率越高可存储的信息越少，但对二维码清晰度的要求越小
        qrcode.setQrcodeErrorCorrect(ecc);
        qrcode.setQrcodeEncodeMode(‘B‘);
        // 设置设置二维码尺寸，取值范围1-40，值越大尺寸越大，可存储的信息越大
        qrcode.setQrcodeVersion(version);
        // 获得内容的字节数组，设置编码格式
        byte[] contentBytes = content.getBytes("utf-8");  

        double ratio = 3;//默认放大三倍
        int qrcodeSize = 21 + 4 * (version - 1);
        if(size > 0){
            ratio = (double)size / qrcodeSize;
        }
        int intRatio = (int)Math.ceil(ratio);

        //旁白
        int padding = (int)Math.ceil(qrcodeSize * intRatio * PADDING_RATIO);
        if(padding < 10){
            padding = 10;
        }

        // 图片尺寸
        int imageSize = qrcodeSize * intRatio + padding * 2;
        image = new BufferedImage(imageSize, imageSize, BufferedImage.TYPE_INT_RGB);
        Graphics2D gs = image.createGraphics();
        // 设置背景颜色
        gs.setBackground(Color.WHITE);
        gs.clearRect(0, 0, imageSize, imageSize);  

        // 设定图像颜色  BLACK
        gs.setColor(Color.BLACK);

        // 输出内容  二维码
        if (contentBytes.length > 0 && contentBytes.length < 800) {
            boolean[][] codeOut = qrcode.calQrcode(contentBytes);
            for (int i = 0; i < codeOut.length; i++) {
                for (int j = 0; j < codeOut.length; j++) {
                    if (codeOut[j][i]) {
                        gs.fillRect(j * intRatio + padding, i * intRatio + padding, intRatio, intRatio);
                    }
                }
            }
        } else {
            throw new Exception("QRCode content bytes length = " + contentBytes.length + " not in [0, 800].");
        }

        if(logo != null){
            int logoSize = imageSize / 4;
            int p = ( imageSize - logoSize ) / 2;
            logo = ImageUtils.setRadius(logo);
            gs.drawImage(logo, p,  p, logoSize, logoSize, null);
        }

        gs.dispose();
        image.flush();

        if(intRatio > ratio){
            image = resize(image, (int)Math.ceil(ratio * imageSize / intRatio ));
        }
        return image;
    }

    /**
     * 生成二维码
     * @param content
     * @param size
     * @param version
     * @param ecc
     * @return
     * @throws Exception
     */
    public static BufferedImage encode(String content, int size, int version, char ecc) throws Exception{
        return encode(content, size, version, ecc, null);
    }

    /**
     * 生成二维码
     * @param content
     * @param size
     * @return
     * @throws Exception
     */
    public static BufferedImage encode(String content, int size) throws Exception{
        return encode(content, size, 9, CORRECT_Q);
    }

    /**
     * 生成二维码
     * @param content
     * @param size
     * @param version
     * @return
     */
    public static BufferedImage encode(String content, int size, int version) throws Exception{
        return encode(content, size, version, CORRECT_Q);
    }

    /**
     * 生成二维码
     * @param content
     * @param size
     * @param logo
     * @return
     */
    public static BufferedImage encode(String content, int size, BufferedImage logo) throws Exception{
        return encode(content, size, 9, CORRECT_Q, logo);
    }

    /**
     * 生成二维码
     * @param content
     * @param size
     * @param ecc
     * @return
     */
    public static BufferedImage encode(String content, int size, char ecc) throws Exception{
        return encode(content, size, 9, ecc);
    }

    /**
     * 生成二维码
     * @param content
     * @return
     */
    public static BufferedImage encode(String content) throws Exception{
        return encode(content, 0, 9, CORRECT_Q);
    }

    /**
     * 解析二维码
     * @throws UnsupportedEncodingException
     * @throws DecodingFailedException
     */
    public static String decode(BufferedImage bufferedImage) throws DecodingFailedException, UnsupportedEncodingException{
         QRCodeDecoder decoder = new QRCodeDecoder();
         return new String(decoder.decode(new MyQRCodeImage(bufferedImage)), "utf-8");
    }

    /**
     * 图片缩放
     */
    private static BufferedImage resize(BufferedImage image, int size){
        BufferedImage bufferedImage = new BufferedImage(size, size, BufferedImage.TYPE_INT_RGB);
        Graphics2D gs = bufferedImage.createGraphics();
        gs.setBackground(Color.WHITE);
        gs.clearRect(0, 0, size, size);
        gs.setColor(Color.BLACK);
        gs.fillRect(0, 0, size, size);
        gs.drawImage(image, 0, 0, size, size, null);
        gs.dispose();
        image.flush();
        return bufferedImage;
    }

}