下载接口

@ApiOperation(value = "下载文件-pdf", notes = "下载文件pdf版", httpMethod = "GET", response = WebResult.class)@RequestMapping(value = "/downloadPdf", method = RequestMethod.GET)public void downloadFilePdf(@RequestParam(name = "id") String id,@RequestParam(name = "fileExt", defaultValue = "", required = false) String fileExt,@RequestParam(name = "fileName", defaultValue = "", required = false) String fileName,@RequestParam(name = "userName", defaultValue = "", required = false) String userName,@RequestParam(name = "key", defaultValue = "", required = false) String key,HttpServletRequest request, HttpServletResponse response) throws Exception {String fileId = fileInfoService.getFileIdByMainId(id, fileExt);GridFSFile gfsfile = mongoDbFileService.getFSFile(fileId);String realFileName = gfsfile.getFilename().replace(",", "");if (StrUtil.isEmpty2(fileName)) {fileName = realFileName;} else {fileName = fileName.concat(".").concat(FileUtil.getFileExt(realFileName));}//处理中文文件名乱码if (request.getHeader("User-Agent").toUpperCase().contains("MSIE") ||request.getHeader("User-Agent").toUpperCase().contains("TRIDENT")|| request.getHeader("User-Agent").toUpperCase().contains("EDGE")) {fileName = java.net.URLEncoder.encode(fileName, "UTF-8");} else {//非IE浏览器的处理：fileName = new String(fileName.getBytes("UTF-8"), "ISO-8859-1");}// 通知浏览器进行文件下载int lastDotIndex = fileName.lastIndexOf('.');String fileNameWithoutExtension = fileName.substring(0, lastDotIndex);response.setHeader("Content-Disposition", "attachment;filename=\"" + fileNameWithoutExtension +".pdf" + "\"");// 获取pdf文件，并添加水印在返回pdf// todo 获取用户名，解决中文水印报错bugString watermark = "";DateTime date = DateUtil.date();String time = DateUtil.format(date, "yyyy-MM-dd");watermark = watermark + time+ "" + userName;OutputStream out = response.getOutputStream();PdfUtil.two(tempPathPdf+id+".pdf",out,key,watermark);}

工具类

import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.PDPage;
import org.apache.pdfbox.pdmodel.PDPageContentStream;
import org.apache.pdfbox.pdmodel.encryption.AccessPermission;
import org.apache.pdfbox.pdmodel.encryption.StandardProtectionPolicy;
import org.apache.pdfbox.pdmodel.font.PDType0Font;
import org.apache.pdfbox.pdmodel.font.PDType1Font;
import org.apache.pdfbox.util.Matrix;import java.io.File;
import java.io.IOException;
import java.io.OutputStream;/*** @author csb* @description: TODO* @date 2023/11/20 17:05*/
public class PdfUtil {//加密和加水印public static void two (String in, OutputStream out, String password, String watermark) throws IOException {// 加载PDF文件PDDocument document = PDDocument.load(new File(in));// 创建访问权限对象AccessPermission accessPermission = new AccessPermission();accessPermission.setCanPrint(true);accessPermission.setCanModify(false);accessPermission.setCanFillInForm(false);accessPermission.setCanExtractContent(false);// 创建保护策略对象StandardProtectionPolicy protectionPolicy = new StandardProtectionPolicy("password", password, accessPermission);// 应用保护策略到文档document.protect(protectionPolicy);//加载本地字体文件，解决中文bug PDType0Font font = PDType0Font.load(document, new File("D:\\11.ttf"));// 加水印 遍历每一页for (PDPage page : document.getPages()) {// 创建内容流以在页面上绘制文本PDPageContentStream contentStream = new PDPageContentStream(document, page, PDPageContentStream.AppendMode.APPEND, true);// 设置字体、颜色和透明度contentStream.setFont(font, 36);contentStream.setNonStrokingColor(200, 200, 200); // 灰色contentStream.setLineWidth(5);// 计算水印位置（居中）float pageHeight = page.getMediaBox().getHeight();float pageWidth = page.getMediaBox().getWidth();// 添加水印文本contentStream.beginText();for (int h = 10; h < pageHeight; h = h + 300) {for (int w = -10; w < pageWidth; w = w + 300) {contentStream.setTextMatrix(Matrix.getRotateInstance(0.4, w, h));contentStream.showText(watermark);}}contentStream.endText();contentStream.restoreGraphicsState();// 关闭内容流并保存更改contentStream.close();}// 保存加密后的PDF文件document.save(out);// 关闭文档document.close();out.close();}public static void WatermarkPDF(String in) throws IOException {// 加载PDF文档PDDocument document = PDDocument.load(new File("input.pdf"));// 遍历每一页for (PDPage page : document.getPages()) {// 创建内容流以在页面上绘制文本PDPageContentStream contentStream = new PDPageContentStream(document, page, PDPageContentStream.AppendMode.APPEND, true);// 设置字体、颜色和透明度contentStream.setFont(PDType1Font.HELVETICA_BOLD, 36);contentStream.setNonStrokingColor(200, 200, 200); // 灰色contentStream.setLineWidth(5);// 计算水印位置（居中）float x = page.getMediaBox().getWidth() / 2;float y = page.getMediaBox().getHeight() / 2;// 添加水印文本contentStream.beginText();contentStream.newLineAtOffset(x, y);contentStream.showText("水印");contentStream.endText();// 关闭内容流并保存更改contentStream.close();}// 保存带有水印的PDF文档document.save("output.pdf");// 关闭文档document.close();}public static void SetPdfPassword (String in){try {// 加载PDF文件PDDocument document = PDDocument.load(new File(in));// 创建访问权限对象AccessPermission accessPermission = new AccessPermission();accessPermission.setCanPrint(true);accessPermission.setCanModify(false);accessPermission.setCanFillInForm(false);accessPermission.setCanExtractContent(false);// 创建保护策略对象StandardProtectionPolicy protectionPolicy = new StandardProtectionPolicy("password", "123456", accessPermission);// 应用保护策略到文档document.protect(protectionPolicy);//            // 保存加密后的PDF文件document.save("D:\\test\\pdf\\2.pdf");// 关闭文档document.close();} catch (IOException e) {e.printStackTrace();}}}

maven

<dependency><groupId>org.apache.pdfbox</groupId><artifactId>pdfbox</artifactId><version>2.0.6</version>
</dependency><dependency><groupId>com.artofsolving</groupId><artifactId>jodconverter</artifactId><version>2.2.1</version>
</dependency>