Springboot生成二维码

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一、引入依赖

		<!-- https://mvnrepository.com/artifact/com.google.zxing/core -->
		<dependency>
			<groupId>com.google.zxing</groupId>
			<artifactId>core</artifactId>
			<version>2.1</version>
		</dependency>
		<!-- https://mvnrepository.com/artifact/com.google.zxing/javase -->
		<dependency>
			<groupId>com.google.zxing</groupId>
			<artifactId>javase</artifactId>
			<version>2.1</version>
		</dependency>

二、代码编写

由于博主遇到的业务是需要一次返回多张二维码给前端，所以将生成的二维码图片进行base编码转换成String集合传输给前端进行展示。

public class CodeService {

    // 二维码宽
    private static final int WIDTH = 215;
    // 二维码高
    private static final int HEIGHT = 215;
    // 加文字二维码高
    private static final int WORDHEIGHT = 250;

    private static final int BLACK = 0xff000000;

    private static final int WHITE = 0xFFFFFFFF;


    public static void main(String[] args) throws IOException, WriterException {
        //老人身份证
        String idCard = "321322199709285431";
        //老人名称
        String oldManName = "张三";

        String baseCode = getCode(idCard, oldManName);
        //data:image/jpg;base64 解码格式
        System.out.println("二维码图片对应编码为：" + "data:image/jpg;base64,"+baseCode);
    }


    /**
     * 由老人身份证获取二维码 base64加密
     *
     * @param idCard
     * @return
     */
    private static String getCode(String idCard, String oldManName)
            throws IOException, WriterException {

        BASE64Encoder encoder = new BASE64Encoder();

//        idCard = encoder.encode(idCard.getBytes());

        idCard = new String(idCard.getBytes(StandardCharsets.UTF_8), StandardCharsets.ISO_8859_1);

        BitMatrix bitMatrix = new MultiFormatWriter()
                .encode(idCard, BarcodeFormat.QR_CODE, 215, 250);

        BufferedImage image = toBufferedImage(bitMatrix, oldManName);

        ByteArrayOutputStream out = new ByteArrayOutputStream();

        ImageIO.write(image, "png", out);

        //TODO:jdk 1.8 base64编码输出每行不超过76字符，并且使用“\n’作为分割。编码输出最后没有行分割，所以需要进行处理 否则无法展示
        return encoder.encode(out.toByteArray()).replaceAll("[\r\n]", "");
    }


    /**
     * 生成二维码内容<br>
     *
     * @param matrix
     * @return
     */
    public static BufferedImage toBufferedImage(BitMatrix matrix, String oldManName) {
        int width = matrix.getWidth();
        int height = matrix.getHeight();
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
        for (int x = 0; x < width; x++) {
            for (int y = 0; y < height; y++) {
                image.setRGB(x, y, matrix.get(x, y) ? BLACK : WHITE);
            }
        }
        image = insertWords(image, oldManName);
        return image;
    }

    /**
     * 把带logo的二维码下面加上文字
     *
     * @param image
     * @param words
     * @return
     */
    private static BufferedImage insertWords(BufferedImage image, String words) {
        //创建一个带透明色的BufferedImage对象
        BufferedImage outImage = new BufferedImage(WIDTH, WORDHEIGHT, BufferedImage.TYPE_INT_ARGB);
        Graphics2D outg = outImage.createGraphics();
        setGraphics2D(outg);

        // 画二维码到新的面板
        outg.drawImage(image, 0, 0, image.getWidth(), image.getHeight(), null);
        // 画文字到新的面板
        Color color = new Color(40, 40, 40);
        outg.setColor(color);
        // 字体、字型、字号

        outg.setFont(new Font("方正粗黑宋简体", Font.BOLD, 18));
        //文字长度
        int strWidth = outg.getFontMetrics().stringWidth(words);
        //总长度减去文字长度的一半  （居中显示）
        int wordStartX = (WIDTH - strWidth) / 2;
        //height + (outImage.getHeight() - height) / 2 + 12
        int wordStartY = HEIGHT + 10;
        // 画文字
        outg.drawString(words, wordStartX, wordStartY);
        outg.dispose();
        outImage.flush();
        return outImage;
    }

    /**
     * 设置 Graphics2D 属性  （抗锯齿）
     *
     * @param graphics2D
     */
    private static void setGraphics2D(Graphics2D graphics2D) {
        graphics2D.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                RenderingHints.VALUE_ANTIALIAS_ON);
        graphics2D.setRenderingHint(RenderingHints.KEY_STROKE_CONTROL,
                RenderingHints.VALUE_STROKE_DEFAULT);
        Stroke s = new BasicStroke(1, BasicStroke.CAP_ROUND, BasicStroke.JOIN_MITER);
        graphics2D.setStroke(s);
    }

}

三、二维码校验

执行main方法会生成字符串，将字符串复制进行在线解码查看是否正确。

base图片在线解码，点击前往

成功！