使用itext7为已有pdf生成目录

package com.newcore.ecs.service.tps.utils;



//需要导入的包
import com.itextpdf.io.font.PdfEncodings;
import com.itextpdf.kernel.font.PdfFont;
import com.itextpdf.kernel.font.PdfFontFactory;
import com.itextpdf.kernel.pdf.*;
import com.itextpdf.kernel.pdf.action.PdfAction;
import com.itextpdf.kernel.pdf.canvas.draw.DottedLine;
import com.itextpdf.layout.Document;
import com.itextpdf.layout.element.Paragraph;
import com.itextpdf.layout.element.Tab;
import com.itextpdf.layout.element.TabStop;
import com.itextpdf.layout.element.Text;
import com.itextpdf.layout.property.Property;
import com.itextpdf.layout.property.TabAlignment;
import com.itextpdf.layout.property.TextAlignment;

import org.springframework.stereotype.Service;


import java.io.File;
import java.io.IOException;
import java.util.Map;
import java.util.TreeMap;

@Service("PrintPdfUtilNew")
public class PrintPdfUtilNew {



   /**
    * 生成一个带有目录(可跳转)的pdf文件(支持中文).
    * 如果目录两页,请为pdf多留出一页空白内容.
    * 此方法不能生成书签.
    *
    * @param sourceFile      源pdf文件
    * @param targetFile      带有目录(可跳转)的pdf文件
    * @param catalogs        目录数据map<标题,页码>
    * @param catalogTitle    目录上方第一行文字
    * @param catalogPageSize 目录占页大小(为锚点偏移做参数)
    * @return targetFile
    * @throws IOException
    */
   public static String createPdfWithCatalog(String sourceFile,String targetFile,

                                   String catalogTitle,
                                   Map<String, Integer> catalogs,
                                   int catalogPageSize) throws IOException {
      Map<String, Integer> catalogsTemp = new TreeMap<>();
      catalogsTemp.putAll(catalogs);
      //实际页码索引偏移量为 目录占页数-1
      int offset = catalogPageSize - 1;
      for (Map.Entry<String, Integer> entry : catalogsTemp.entrySet()) {
         entry.setValue(entry.getValue() + offset);
      }

      File file = new File(targetFile);
      file.getParentFile().mkdirs();
      PdfDocument pdfDoc = new PdfDocument(new PdfWriter(targetFile));
      Document document = new Document(pdfDoc);

      //处理中文问题

//    此方式会抛异常（com.itextpdf.io.IOException: The CMap com/itextpdf/io/font/cmap/UniGB-UTF16-H was not found.）所以采用本地字体
//    PdfFont font = PdfFontFactory.createFont("STSong-Light", "UniGB-UCS2-H", false);
      PdfFont font = PdfFontFactory.createFont("C:\\Windows\\Fonts\\simsun.ttc,0", PdfEncodings.IDENTITY_H, false);

      if (catalogTitle == null) {
         catalogTitle = " ";
      }
      document.add(new Paragraph(new Text(catalogTitle))
            .setTextAlignment(TextAlignment.CENTER).setFont(font));
      PdfDocument firstSourcePdf = new PdfDocument(new PdfReader(sourceFile));
      int numberOfPages = firstSourcePdf.getNumberOfPages();
      for (int i = 1; i <= numberOfPages; i++) {
         PdfPage page = firstSourcePdf.getPage(i).copyTo(pdfDoc);
         pdfDoc.addPage(page);
         for (Map.Entry<String, Integer> entry : catalogsTemp.entrySet()) {
            if (i == entry.getValue()) {
               String destinationKey = "p" + (pdfDoc.getNumberOfPages() - 1);
               PdfArray destinationArray = new PdfArray();
               destinationArray.add(page.getPdfObject());
               destinationArray.add(PdfName.XYZ);
               destinationArray.add(new PdfNumber(0));
               destinationArray.add(new PdfNumber(page.getMediaBox().getHeight()));
               destinationArray.add(new PdfNumber(1));
               try {
                  pdfDoc.addNamedDestination(destinationKey, destinationArray);
               } catch (Exception e) {
                  System.out.println(e.getMessage());
               }
               Paragraph p = new Paragraph();
               p.setFont(font);
               p.addTabStops(new TabStop(540, TabAlignment.RIGHT, new DottedLine()));
               p.add(entry.getKey());
               p.add(new Tab());
               p.add(String.valueOf(pdfDoc.getNumberOfPages() - 1));
               p.setProperty(Property.ACTION, PdfAction.createGoTo(destinationKey));
               document.add(p);
            }
         }
      }
      firstSourcePdf.close();
      document.close();
      return targetFile;
   }
   /**
    * 新改的方法 ,生成目录pdf ,只是为了方便计算页数.
    * 基于createPdfWithCatalog()代码改编,该方法进保留生成目录功能.
    *
    * @param sourceFile sourceFile
    * @param targetFile targetFile
    * @param catalogs   catalogs
    * @return 目录页数 page size
    * @throws IOException IOException
    */
   public static int createCatalogPdfOnly(String sourceFile, String targetFile, Map<String, Integer> catalogs) throws IOException {
      File file = new File(targetFile);
      file.getParentFile().mkdirs();
      PdfDocument pdfDoc = new PdfDocument(new PdfWriter(targetFile));
      Document document = new Document(pdfDoc);
      document.add(new Paragraph(new Text("The Revenant nominations list"))
            .setTextAlignment(TextAlignment.CENTER));
      PdfDocument firstSourcePdf = new PdfDocument(new PdfReader(sourceFile));
      for (Map.Entry<String, Integer> entry : catalogs.entrySet()) {
         Paragraph p = new Paragraph();
         p.addTabStops(new TabStop(540, TabAlignment.RIGHT, new DottedLine()));
         p.add(entry.getKey());
         p.add(new Tab());
         p.add(String.valueOf(pdfDoc.getNumberOfPages() - 1));
         document.add(p);
      }
      firstSourcePdf.close();
      int pages = pdfDoc.getNumberOfPages();
      document.close();
      return pages;
   }
   public static void main(String[] args){

      Map<String, Integer> catalogs = new TreeMap<>();
      catalogs.put("封面", 1);
      catalogs.put("保单", 2);
      catalogs.put("现价", 3);
      catalogs.put("条款", 4);
      catalogs.put("投保资料-投保单", 12);
      catalogs.put("投保资料-合同审核函", 16);
      catalogs.put("投保资料-转账不成功通知函", 17);
      catalogs.put("投保资料-核保通知函", 18);
      catalogs.put("投保资料-体检报告中健康告知页", 19);
      catalogs.put("投保资料-首期保险费溢交通知书", 20);
      catalogs.put("投保资料-保险款项自动转账授权书", 21);
      catalogs.put("投保资料-未成年人投保特别告知书", 22);
      catalogs.put("收据与送达回执", 23);
      catalogs.put("封底", 24);



      try{
         int catalogPdfPageSize =createCatalogPdfOnly("E://blank.pdf", "E://bb.pdf", catalogs);
         createPdfWithCatalog("E://test.pdf", "E://bb.pdf", "PICC电子保单", catalogs, catalogPdfPageSize);

      }catch(Exception e){
           e.printStackTrace();
      }
       



   }
}

maven引用如下：

<dependency>
    <groupId>com.itextpdf</groupId>
    <artifactId>kernel</artifactId>
    <version>7.0.7</version>
</dependency>
<dependency>
    <groupId>com.itextpdf</groupId>
    <artifactId>layout</artifactId>
    <version>7.0.7</version>
</dependency>