java后端:实现导出excel,按其中一个列的数据生成二维码图片,显示在列表中
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新手记录自己的用过的工具,要是能帮到码友就更好了。借鉴:(借鉴的文章找不到了)
需求分析:
实现导出excel,二维码根据编号生成,二维码图片不存储在数据库(刚看到需求,还以为要把二维码图片存在数据库,前辈说完全没必要存)
运行环境及框架: idea、springboot、
实现:
第一步:导入依赖
<!--zxing--> <dependency> <groupId>com.google.zxing</groupId> <artifactId>javase</artifactId> <version>3.2.1</version> </dependency> <dependency> <groupId>com.google.zxing</groupId> <artifactId>core</artifactId> <version>3.2.1</version> </dependency> <dependency> <groupId>org.jeecg</groupId> <artifactId>easypoi-base</artifactId> <version>2.3.1</version> </dependency> <!--zxing-->
第二步:放在工具类
import com.google.zxing.BarcodeFormat; import com.google.zxing.WriterException; import com.google.zxing.common.BitMatrix; import com.google.zxing.qrcode.QRCodeWriter; import com.zkhb.boot.ponder.common.utils.common.QRCodeUtil; import com.zkhb.boot.ponder.common.web.exception.PonderException; import com.zkhb.boot.ponder.services.pound.entity.PoundCasualUser; import com.zkhb.boot.ponder.services.pound.vo.report.PoundCasualUserReport; import lombok.extern.slf4j.Slf4j; import org.apache.poi.ss.usermodel.Workbook; import org.jeecgframework.poi.excel.ExcelExportUtil; import org.jeecgframework.poi.excel.entity.ExportParams; import javax.imageio.ImageIO; import javax.servlet.http.HttpServletResponse; import java.awt.image.BufferedImage; import java.io.BufferedOutputStream; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.OutputStream; import java.net.URLEncoder; import java.util.ArrayList; import java.util.List; /** * @author Chen * @Description: * @ClassName:ExeclUtil * @date 2020/7/7 12:46 * @Version: 1.0 * @RETURN */ @Slf4j public class ExcelUtil { /** * 导出excel * * @param response HttpServletResponse * @param fileName 文件名字 * @param workbook 通过exportPicture()方法获取 * @author zhy */ public static void writeExcel(HttpServletResponse response, String fileName, Workbook workbook) { // 判断数据 if (workbook == null) { throw new PonderException("错误"); } // 重置响应对象 response.reset(); try { OutputStream outputStream = getOutputStream(fileName, response); BufferedOutputStream bufferedOutPut = new BufferedOutputStream(outputStream); workbook.write(bufferedOutPut); bufferedOutPut.flush(); bufferedOutPut.close(); outputStream.close(); } catch (IOException e) { log.error(e.getMessage()); } } /** * 导出文件时为Writer生成OutputStream * * @param fileName 文件名字 * @param response response * @return 输出流 * @author zhy */ private static OutputStream getOutputStream(String fileName, HttpServletResponse response) { try { fileName = URLEncoder.encode(fileName, "UTF-8"); response.setContentType("application/vnd.ms-excel"); response.setCharacterEncoding("utf8"); response.setHeader("Content-Disposition", "attachment; filename=" + fileName + ".xls"); response.setHeader("Pragma", "public"); response.setHeader("Cache-Control", "no-store"); response.addHeader("Cache-Control", "max-age=0"); return response.getOutputStream(); } catch (IOException e) { throw new PonderException("导出excel表格失败!"); } } /** * 获取Workbook对象 * * @param pigList 查询黑猪对象列表 * @param aesPassword aes加密密码 * @param qrCodeUrl 溯源网址前缀 * @return 文件下载 * @author zhy */ public static Workbook exportPicture(List<PoundCasualUser> pigList, String aesPassword, String qrCodeUrl) { List<PoundCasualUserReport> list = new ArrayList<>(); pigList.forEach(item -> { PoundCasualUserReport e = new PoundCasualUserReport(); e.setTransportType(item.getTransportType()==0 ? "一车一货":"一车多货"); e.setCardNo(item.getCardNo()); String text=item.getCardNo(); QRCodeWriter qrCodeWriter = new QRCodeWriter(); BitMatrix bitMatrix = null; try { bitMatrix = qrCodeWriter.encode(text, BarcodeFormat.QR_CODE, 150, 150); } catch (WriterException e1) { e1.printStackTrace(); } BufferedImage image = QRCodeUtil.toBufferedImage(bitMatrix); byte[] pngs = imageToBytes(image); e.setQrCode(pngs); list.add(e); }); return ExcelExportUtil.exportExcel(new ExportParams(), PoundCasualUserReport.class, list); } /** * BufferedImage转byte[] * * @param bImage BufferedImage对象 * @return byte[] * @auth zhy */ private static byte[] imageToBytes(BufferedImage bImage) { ByteArrayOutputStream out = new ByteArrayOutputStream(); try { ImageIO.write(bImage, "png", out); } catch (IOException e) { log.error(e.getMessage()); } return out.toByteArray(); } }
第三步:controller层 @ApiOperation("导出") @RequestMapping(value = "/export")
public Result export( @RequestParam(value = "ids") @ApiParam(value = "要导出的id,多个用逗号隔开", required = true) String ids, HttpServletRequest request,HttpServletResponse response)throws Exception{
//获取List集合(替换上你要导出的集合) List<PoundCasualUser> poundCasualUserList=poundCasualUserService.getCasualUserList(ids);
//导出的excel名 String fileName = "临时用户列表" + DateUtils.formatDate(new Date(), "yyyyMMddHHmmss");
//调用导出的方法 ExcelUtil.writeExcel(response,fileName,ExcelUtil.exportPicture(poundCasualUserList,null,null)); return null; }
效果:
用swagger调用接口,导出的没有数据,但是前端调用的效果如下:(有大佬知道什么问题的话,望指教)
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