背景图和二维码合成

需求: 类似于做一个码牌, UI提供背景图模板, 后端将二维码合成到背景图模板中

背景图模板                                                最终效果图

 

开撸

package cc.sunni;

import cn.hutool.core.util.StrUtil;
import cn.hutool.extra.qrcode.QrCodeUtil;
import cn.hutool.extra.qrcode.QrConfig;
import org.springframework.core.io.ClassPathResource;
import sun.misc.BASE64Encoder;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;

/**
 * 码牌: 将二维码合成到背景图片中
 *
 * @author 江黎
 * @since 2022-07-21
 */
public class QrCodeCard {

    /**
     * 二维码的宽度
     */
    private static final int QR_CODE_WIDTH = 640;
    /**
     * 二维码的高度
     */
    private static final int QR_CODE_HEIGHT = 640;
    /**
     * title字体
     */
    private static final Font TITLE_FONT = new Font("宋体", Font.BOLD, 30);
    /**
     * desc字体
     */
    private static final Font DESC_FONT = new Font("宋体", Font.PLAIN, 25);
    /**
     * bottom字体
     */
    private static final Font BOTTOM_FONT = new Font("宋体", Font.ITALIC, 24);

    private static final String FORMAT_NAME = "PNG";

    /**
     * @param title           标题
     * @param desc            描述
     * @param content         二维码内容
     * @param bottom          底部文字
     * @param imgLogo         二维码中间图片地址
     * @param backgroundImage 背景图片地址
     * @param imageY          二维码在背景图片的Y轴位置, X轴是居中的
     * @return 返回BufferedImage方便后续处理是生成图片还是生成base64字符串
     */
    public static BufferedImage createQrCode(String title, String desc, String content, String bottom, String imgLogo, String backgroundImage, int imageY) throws IOException {
        // 创建主模板图片
        int maxWidth = getMaxWidth(title, desc, bottom);
        int maxHeight = getMaxHeight();
        BufferedImage image = new BufferedImage(maxWidth, maxHeight, BufferedImage.TYPE_INT_RGB);
        Graphics2D graphics = image.createGraphics();
        if (StrUtil.isNotBlank(backgroundImage)) {
            // 设置图片的背景色为透明, 需要合成到背景图片就设置为透明
            image = graphics.getDeviceConfiguration().createCompatibleImage(maxWidth, maxHeight, Transparency.TRANSLUCENT);
        } else {
            // 设置图片的背景色为白色
            graphics.setColor(Color.white);
        }

        graphics.fillRect(0, 0, maxWidth, maxHeight);

        // 动态高度
        int height = 0;

        // *********************** title ***********************
        if (StrUtil.isNotBlank(title)) {
            graphics = image.createGraphics();
            // 设置字体颜色 black黑 white白
            graphics.setColor(Color.black);
            // 设置字体
            graphics.setFont(TITLE_FONT);
            graphics.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_LCD_HRGB);
            // 居中 x开始的位置：（图片宽度-字体大小*字的个数）/2
            int x = (maxWidth - (TITLE_FONT.getSize() * title.length())) / 2;
            int strHeight = getStringHeight(graphics);
            graphics.drawString(title, x, strHeight);
            height += strHeight;
        }

        // ********************** desc **********************
        if (StrUtil.isNotBlank(desc)) {
            graphics = image.createGraphics();
            // 设置字体颜色，先设置颜色，再填充内容
            graphics.setColor(Color.black);
            // 设置字体
            graphics.setFont(DESC_FONT);
            graphics.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_LCD_HRGB);
            // 获取字符高度
            int strHeight = getStringHeight(graphics);
            // 按行居中显示
            String[] info = desc.split("\\$");  // 多行文字以 $ 分隔
            for (int i = 0; i < info.length; i++) {
                String s = info[i];
                // x开始的位置：（图片宽度-字体大小*字的个数）/2
                int strWidth = graphics.getFontMetrics().stringWidth(s);
                // 总长度减去文字长度的一半  （居中显示）
                int startX = (maxWidth - strWidth) / 2;
                height += strHeight * (i + 1);
                graphics.drawString(s, startX, height);
            }
        }

        // ********************** 插入二维码图片 **********************
        Graphics codePic = image.getGraphics();
        BufferedImage codeImg;
        QrConfig config = new QrConfig();
        config.setMargin(2);
        config.setWidth(QR_CODE_WIDTH);
        config.setHeight(QR_CODE_HEIGHT);
        if (StrUtil.isNotBlank(imgLogo)) {
            config.setImg(imgLogo);
        }
        codeImg = QrCodeUtil.generate(content, config);
        // 绘制二维码
        codePic.drawImage(codeImg, (maxWidth - QR_CODE_WIDTH) / 2, height, QR_CODE_WIDTH, QR_CODE_HEIGHT, null);
        codePic.dispose();

        // ********************** bottom **********************
        if (StrUtil.isNotBlank(bottom)) {
            graphics = image.createGraphics();
            // 设置字体颜色
            graphics.setColor(Color.black);
            // 设置字体
            graphics.setFont(BOTTOM_FONT);
            graphics.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_LCD_HRGB);
            // x开始的位置：（图片宽度-字体大小*字的个数）/2
            int startX = (maxWidth - (BOTTOM_FONT.getSize() * bottom.length())) / 2;
            // 获取字符高度
            int footerStrHeight = getStringHeight(graphics);
            height += QR_CODE_HEIGHT + footerStrHeight;
            graphics.drawString(bottom, startX, height);
        }

        if (StrUtil.isNotBlank(backgroundImage)) {
            // 加载背景模板
            ClassPathResource resource = new ClassPathResource(backgroundImage);
            InputStream inputStream = resource.getInputStream();
            BufferedImage templateImage = ImageIO.read(inputStream);
            Graphics graphicsTemplate = templateImage.getGraphics();
            // 根据模板宽度 - 二维码宽度 进行居中算出X坐标
            int widthX = (templateImage.getWidth() - image.getWidth()) / 2;
            // 添加二维码
            graphicsTemplate.drawImage(image, widthX, imageY, null);
            graphicsTemplate.dispose();
            return templateImage;
        } else {
            return image;
        }
    }

    // 生成图片文件
    public static void createImage(BufferedImage image, String fileLocation) {
        if (image != null) {
            try {
                ImageIO.write(image, "png", new File(fileLocation));
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    // 获取图片base64数据
    public static String base64ImageString(BufferedImage image) throws IOException {
        ByteArrayOutputStream bos = new ByteArrayOutputStream();//io流
        ImageIO.write(image, FORMAT_NAME, bos);//写入流中
        byte[] bytes = bos.toByteArray();//转换成字节
        BASE64Encoder encoder = new BASE64Encoder();
        String jpgBase64 = encoder.encodeBuffer(bytes).trim();//转换成base64串
        jpgBase64 = jpgBase64.replaceAll("\n", "").replaceAll("\r", "");//删除 \r\n
        return "data:image/jpg;base64," + jpgBase64;
    }

    // 字符串总宽度
    private static int getStringLength(Graphics g, String str) {
        char[] chars = str.toCharArray();
        return g.getFontMetrics().charsWidth(chars, 0, str.length());
    }

    // 字符高度
    private static int getStringHeight(Graphics g) {
        return g.getFontMetrics().getHeight();
    }

    // 每一行字符的个数
    private static int getRowStrNum(int strNum, int rowWidth, int strWidth) {
        return (rowWidth * strNum) / strWidth;
    }

    // 字符行数
    private static int getRows(int strWidth, int rowWidth) {
        int rows;
        if (strWidth % rowWidth > 0) {
            rows = strWidth / rowWidth + 1;
        } else {
            rows = strWidth / rowWidth;
        }
        return rows;
    }

    // 计算二维码图片最大宽度
    private static int getMaxWidth(String title, String desc, String bottom) {
        int width = 0;
        BufferedImage image = new BufferedImage(QR_CODE_WIDTH, QR_CODE_HEIGHT, BufferedImage.TYPE_INT_RGB);
        Graphics2D graphics = image.createGraphics();
        if (StrUtil.isNotBlank(title)) {
            width = Math.max(getStringLength(graphics, title), width);
        }
        if (StrUtil.isNotBlank(desc)) {
            width = Math.max(getStringLength(graphics, desc), width);
        }
        if (StrUtil.isNotBlank(bottom)) {
            width = Math.max(getStringLength(graphics, bottom), width);
        }
        return Math.max(QR_CODE_WIDTH, width);
    }

    // 计算二维码图片最大高度
    private static int getMaxHeight() {
        int height = QR_CODE_HEIGHT;
        BufferedImage image = new BufferedImage(QR_CODE_WIDTH, QR_CODE_HEIGHT, BufferedImage.TYPE_INT_RGB);
        Graphics2D graphics = image.createGraphics();
        graphics.setFont(TITLE_FONT);
        height += getStringHeight(graphics);
        graphics.setFont(DESC_FONT);
        height += getStringHeight(graphics);
        graphics.setFont(BOTTOM_FONT);
        height += getStringHeight(graphics);
        return height;
    }

    public static void main(String[] args) throws IOException {
        String title = "码牌";
        String desc = "知名互联网公司CEO";
        String content = "https://www.baidu.com";
        String logo = "templates/[email protected]";
        String bottom = "国家认证";
        String backgroundImage = "templates/announcer.png";
//        BufferedImage bufferedImage = createQrCode(null, null, content, logo, null, backgroundImage, 290);
        BufferedImage bufferedImage = createQrCode(title, desc, content, logo, bottom, backgroundImage, 290);
        createImage(bufferedImage, "D:/test.png");
    }
}

不带背景图                        ​​​​​​​        ​​​​​​​        ​​​​​​​        ​​​​​​​                 带背景图

 

 附上下载的方法
​​​​

@RestController
public class Controller {

    @PostMapping("/downloadQrCode")
    public void downloadQrCode(@RequestParam String content, @RequestParam(required = false) String title,
                               @RequestParam(required = false) String desc, @RequestParam(required = false) String bottom,
                               HttpServletResponse response) throws IOException {
        BufferedImage targetBufferedImage = QrCodeCard.createQrCode(title, desc, content,
                bottom, "templates/[email protected]", "templates/announcer.png", 290);
        OutputStream os = response.getOutputStream();
        response.setCharacterEncoding(Charsets.UTF_8.name());
        response.setContentType("multipart/form-data");
        response.setHeader("content-type", "image/png");
        ImageIO.write(targetBufferedImage, "png", os);
    }
}