import java.io.File;

import java.io.FileOutputStream;

import java.io.IOException;

import java.util.List;

import com.itextpdf.text.DocumentException;

import com.itextpdf.text.Image;

import com.itextpdf.text.pdf.PdfContentByte;

import com.itextpdf.text.pdf.PdfReader;

import com.itextpdf.text.pdf.PdfStamper;

public class PdfUtils {

    /**

     * PDF添加图层

     *

     * @param srcPdf

     *            原PDF文件路径

     * @param distPdf

     *            合成PDF输出路径

     * @param layerPathArr

     *            图层路径列表，图层名称需为数字(按照图片名称数字顺序合成在PDF对应页数上)

     * @return

     * @throws IOException

     * @throws DocumentException

     */

    public static String markLocalImage42Dist(String srcPdf, String distPdf, List<String> layerPathArr)

            throws IOException, DocumentException {

            File srcPdfFile = new File(srcPdf);

            if (!srcPdfFile.exists()) {

                throw new IllegalArgumentException("找不到需要添加图层的pdf文件");

            }

            PdfReader reader = new PdfReader(srcPdf);

            int n = reader.getNumberOfPages(); // PDF页数

            PdfStamper stamp = new PdfStamper(reader, new FileOutputStream(distPdf));

            PdfContentByte over;

            for (String layerPath : layerPathArr) {

                File layerFile = new File(layerPath);

                String currentPageNo = layerFile.getName().substring(, layerFile.getName().lastIndexOf(".")); // 图片名称(对应页数)

                boolean isNum = currentPageNo.matches("[0-9]+");

                if (!isNum) {

                    throw new IllegalArgumentException("图层名称是不是数字");

                }

                Image img = Image.getInstance(layerPath);

                img.setAbsolutePosition(, );

                if (n >  && n >= Integer.parseInt(currentPageNo)) {

                    over = stamp.getOverContent(Integer.parseInt(currentPageNo));

                    over.addImage(img);

                }

            }

            stamp.close();

            reader.close();

        return distPdf;

    }

}

public static void main(String[] args) throws IOException, DocumentException {

        List<String> imgUrlList = new ArrayList<>();

        imgUrlList.add("D:/ts/testPDF/1.png");

        //imgUrlList.add("D:/ts/testPDF/2.png");

        imgUrlList.add("D:/ts/testPDF/3.png");

        markLocalImage42Dist("D:/ts/testPDF/testPDF.pdf", "D:/ts/testPDF/testPDF2.pdf", imgUrlList);

    }