java 创建二维码

深藏阁楼爱情的钟 2023-06-20 09:10 107阅读 0赞

##### maven依赖 #####

<dependency>
                <groupId>com.google.zxing</groupId>
                <artifactId>core</artifactId>
                <version>3.4.0</version>
            </dependency>
            <dependency>
                <groupId>com.google.zxing</groupId>
                <artifactId>javase</artifactId>
                <version>3.4.0</version>
            </dependency>

还需要 RestTemplate 访问网络图片使用

##### 工具类 #####

package com.admin.system.util;
    
    
    import com.google.zxing.BarcodeFormat;
    import com.google.zxing.EncodeHintType;
    import com.google.zxing.MultiFormatWriter;
    import com.google.zxing.common.BitMatrix;
    import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
    import org.springframework.core.io.Resource;
    import org.springframework.http.HttpMethod;
    import org.springframework.http.ResponseEntity;
    import org.springframework.web.client.RestTemplate;
    
    import javax.imageio.ImageIO;
    import java.awt.*;
    import java.awt.geom.RoundRectangle2D;
    import java.awt.image.BufferedImage;
    import java.io.InputStream;
    import java.io.OutputStream;
    import java.util.Hashtable;
    
    /** * 生成二维码的工具类 */
    public class QRCodeUtil { 
    
        private static final String CHARSET = "utf-8";
        private static final String FORMAT_NAME = "JPG";
        // 二维码尺寸
        private static final int QRCODE_SIZE = 300;
        // LOGO宽度
        private static final int WIDTH = 60;
        // LOGO高度
        private static final int HEIGHT = 60;
    
        private static BufferedImage createImage(String content, String imgPath, boolean needCompress) throws Exception { 
            Hashtable hints = new Hashtable();
            hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
            hints.put(EncodeHintType.CHARACTER_SET, CHARSET);
            hints.put(EncodeHintType.MARGIN, 1);
            BitMatrix bitMatrix = new MultiFormatWriter().encode(content, BarcodeFormat.QR_CODE, QRCODE_SIZE, QRCODE_SIZE,hints);
            int width = bitMatrix.getWidth();
            int height = bitMatrix.getHeight();
            BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
            for (int x = 0; x < width; x++) { 
                for (int y = 0; y < height; y++) { 
                    image.setRGB(x, y, bitMatrix.get(x, y) ? 0xFF000000 : 0xFFFFFFFF);
                }
            }
            if (imgPath == null || "".equals(imgPath)) { 
                return image;
            }
            // 插入图片
            QRCodeUtil.insertImage(image, imgPath, needCompress);
            return image;
        }
    
    
        private static void insertImage(BufferedImage source, String imgPath, boolean needCompress) throws Exception { 
            RestTemplate restTemplate = new RestTemplate();
            ResponseEntity<Resource> entity = restTemplate.exchange(imgPath, HttpMethod.GET, null, Resource.class);
            InputStream inputStream = entity.getBody().getInputStream();
            Image src = ImageIO.read(inputStream);
            int width = src.getWidth(null);
            int height = src.getHeight(null);
            // 压缩LOGO
            if (needCompress) { 
                if (width > WIDTH) { 
                    width = WIDTH;
                }
                if (height > HEIGHT) { 
                    height = HEIGHT;
                }
                Image image = src.getScaledInstance(width, height, Image.SCALE_SMOOTH);
                BufferedImage tag = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
                Graphics g = tag.getGraphics();
                // 绘制缩小后的图
                g.drawImage(image, 0, 0, null);
                g.dispose();
                src = image;
            }
            // 插入LOGO
            Graphics2D graph = source.createGraphics();
            int x = (QRCODE_SIZE - width) / 2;
            int y = (QRCODE_SIZE - height) / 2;
            graph.drawImage(src, x, y, width, height, null);
            Shape shape = new RoundRectangle2D.Float(x, y, width, width, 6, 6);
            graph.setStroke(new BasicStroke(3f));
            graph.draw(shape);
            graph.dispose();
        }
    
        public static void encode(String content, String imgPath, OutputStream output, boolean needCompress)
                throws Exception { 
            BufferedImage image = QRCodeUtil.createImage(content, imgPath, needCompress);
            ImageIO.write(image, FORMAT_NAME, output);
        }
    
    
        public static void encode(String content, OutputStream output) throws Exception { 
            QRCodeUtil.encode(content, null, output, false);
        }
    }

##### 使用 #####

/**
         * 根据数据生成二维码
         */
        @GetMapping("QrCode")
        public void QrCode(String code) throws IOException {
            ServletOutputStream stream = null;
            try {
                stream = response.getOutputStream();
                //使用工具类生成二维码
                QRCodeUtil.encode(code, stream);
            } catch (Exception e) {
                e.getStackTrace();
            } finally {
                if (stream != null) {
                    stream.flush();
                    stream.close();
                }
            }
        }
    
    
        /**
         * 根据数据生成带有logo二维码
         */
        @GetMapping(value = "/createLogoQrCode")
        public void createLogoQRCode(String code) throws Exception {
            ServletOutputStream stream = null;
            try {
                stream = response.getOutputStream();
                String logoPath = "http://yun-cunchu.oss-cn-beijing.aliyuncs.com/timg.jpg";
                QRCodeUtil.encode(code, logoPath, stream, true);
            } catch (Exception e) {
                e.getStackTrace();
            } finally {
                if (stream != null) {
                    stream.flush();
                    stream.close();
                }
            }
        }