PDF盖骑缝章

对于无纸化操作pdf文件如果需要打印，一般为了保证完整有效性用数字签名就可以了，但是需要打印纸质后数字签名就呵呵了，对于人眼的完整行只能靠骑缝章来简单的保证一下了。所以骑缝章完全事为了人类肉眼识别出来的一个东西。对于要打印的pdf加一个骑缝章，无非就是把章按页数切割成等份的图片，合并在一起罢了。

import com.itextpdf.text.BadElementException;import com.itextpdf.text.DocumentException;import com.itextpdf.text.Image;import com.itextpdf.text.Rectangle;import com.itextpdf.text.pdf.PdfContentByte;import com.itextpdf.text.pdf.PdfReader;import com.itextpdf.text.pdf.PdfStamper;import javax.imageio.ImageIO;import java.awt.image.BufferedImage;import java.io.*;/** * 盖骑缝章 * Created by zhangzhenhua on 2016/11/2. */public class PDFStamperCheckMark {    /**     * 切割图片     * @param imgPath  原始图片路径     * @param n 切割份数     * @return  itextPdf的Image[]     * @throws IOException     * @throws BadElementException     */    public static Image[] subImages(String imgPath,int n) throws IOException, BadElementException {        Image[] nImage = new Image[n];        ByteArrayOutputStream out = new ByteArrayOutputStream();        BufferedImage img = ImageIO.read(new File(imgPath));        int h = img.getHeight();        int w = img.getWidth();        int sw = w/n;        for(int i=0;i<n;i++){            BufferedImage subImg;            if(i==n-1){//最后剩余部分                 subImg = img.getSubimage(i * sw, 0, w-i*sw, h);            }else {//前n-1块均匀切                 subImg = img.getSubimage(i * sw, 0, sw, h);            }            ImageIO.write(subImg,imgPath.substring(imgPath.lastIndexOf('.')+1),out);            nImage[i] = Image.getInstance(out.toByteArray());            out.flush();            out.reset();        }        return nImage;    }    /**     *  盖骑缝章     *     * @param infilePath    原PDF路径     * @param outFilePath    输出PDF路径     * @param picPath    章图片路径     * @throws IOException     * @throws DocumentException     */    public static void stamperCheckMarkPDF(String infilePath,String outFilePath,String picPath) throws IOException, DocumentException {        PdfReader reader = new PdfReader(infilePath);//选择需要印章的pdf        PdfStamper stamp = new PdfStamper(reader, new FileOutputStream(outFilePath));//加完印章后的pdf        Rectangle pageSize = reader.getPageSize(1);//获得第一页        float height = pageSize.getHeight();        float width  = pageSize.getWidth();        int nums = reader.getNumberOfPages();        Image[] nImage =  subImages(picPath,nums);//生成骑缝章切割图片        for(int n=1;n<=nums;n++){            PdfContentByte over = stamp.getOverContent(n);//设置在第几页打印印章            Image img = nImage[n-1];//选择图片//            img.setAlignment(1);//            img.scaleAbsolute(200,200);//控制图片大小            img.setAbsolutePosition(width-img.getWidth(),height/2-img.getHeight()/2);//控制图片位置            over.addImage(img);        }        stamp.close();    }    public static void main(String[] args) throws IOException, DocumentException {        String infilePath = "E:\\项目\\paperless\\page.pdf";        String outfilePaht = "E:\\项目\\paperless\\page_pic.pdf";        String picPath = "E:\\项目\\paperless\\公章.png";        stamperCheckMarkPDF(infilePath,outfilePaht,picPath);    }}

最后效果