java后台生成并下载二维码 hutool-all-4.3.0.jar（以二进制流的形式输出）

亦凉 2021-11-13 21:40 398阅读 0赞

1.导入依赖

<dependency>  
    <groupId>cn.hutool</groupId>  
    <artifactId>hutool-all</artifactId>  
    <version>4.3.0</version>  
</dependency>

2.下面直接上代码

*  controller层

@GetMapping("/downloadQrCode")
        public void downloadQrCode(@RequestParam Map<String, Object> params, HttpServletResponse response) {
            try {
            	String fileName = String.format("%s二维码.zip", params.get("storeSysCode"));
            	response.setContentType("application/x-msdownload");
            	response.setHeader("Content-disposition", "attachment;filename=" + URLEncoder.encode(fileName, "utf-8"));
            	response.addHeader("Access-Control-Allow-Origin", "*");
                OutputStream output = response.getOutputStream();
                ZipOutputStream zip = new ZipOutputStream(output);
                
                service.downloadQrCode(params, zip);
                zip.flush();
                zip.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

*  service层

downloadQrCode方法

@Override
    public void downloadQrCode(Map<String, Object> params, ZipOutputStream zos) {
    	List<TbDto> selectStoreTables = this.baseMapper.selectStoreTables(params);
    	
    	for(TbDto tbDto : selectStoreTables) {
    		QrConfig qrConfig = new QrConfig();
    		qrConfig.setWidth(300);
    		qrConfig.setHeight(300);
    		String doaminUrl = aposPropertiesConfig.getdoaminUrl(); 
    		// /MWT/{storeSysCode}/{areaCode}/{tableCode}
    		String wxShopUri = CommonConstant.WXSHOP_MWT_URI
    				.replace("{storeSysCode}",tbDto.getStoreSysCode())
    				.replace("{areaCode}", tbDto.getAreaCode())
    				.replace("{tableCode}", tbDto.getTableCode());
    		//生成二维码
    		BufferedImage image = QrCodeUtil.generate(doaminUrl + wxShopUri, qrConfig);
    		//二维码绘制tableCode
    		drawTableCode(tbDto, image);
    		//打包成zip
    		try(ByteArrayOutputStream out = new ByteArrayOutputStream()) {
    			ImageUtil.write(image, ImageUtil.IMAGE_TYPE_PNG, out);
    			String fileName = String.format("%s__%s.png", tbDto.getAreaName(), tbDto.getTableName());
    			ZipUtil.doZip(fileName, out.toByteArray(), zos);
    		} catch (IOException e) {
    			e.printStackTrace();
    		}
    	}
    }

二维码绘制tableCode，drawTableCode方法

private void drawTableCode(TbDto tbDto, BufferedImage image) {
    	Graphics2D g2d = (Graphics2D) image.getGraphics();
    	//设置抗锯齿
    	g2d.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
    	int fontSize = 15;
    	Font font = new Font(null, Font.PLAIN, fontSize);
    	g2d.setFont(font);
    	g2d.setColor(Color.black);
    	//int strWidth = graphics.getFontMetrics().stringWidth(tableCode);
    	String fileName = String.format("%s（%s）", tbDto.getTableCode(), tbDto.getTableName());
    	g2d.drawString(fileName, 20, image.getHeight() - 5);
    	g2d.dispose();
    }

ZipUtil工具类

import java.io.ByteArrayInputStream;
    import java.io.IOException;
    import java.util.zip.ZipEntry;
    import java.util.zip.ZipOutputStream;
    
    public class ZipUtil {
    	public static void doZip(String name, byte[] bytes, ZipOutputStream zos) throws IOException {
    		zos.putNextEntry(new ZipEntry(name));
    		ByteArrayInputStream fis = new ByteArrayInputStream(bytes);
    		byte[] buffer = new byte[1024];
    		int r = 0;
    		while ((r = fis.read(buffer)) != -1)
    			zos.write(buffer, 0, r);
    
    		zos.flush();
    		fis.close();
    	}
    
    }