本文介绍使用Spire.PDF for Java来读取PDF中的书签。

import com.spire.pdf.*;
import com.spire.pdf.bookmarks.PdfBookmark;
import com.spire.pdf.bookmarks.PdfBookmarkCollection;

import java.io.FileWriter;
import java.io.IOException;

public class GetBookmark {
    public static void main(String[] args) {
        //加载包含书签的PDF文档
        PdfDocument pdf = new PdfDocument();
        pdf.loadFromFile("AddBookmarks.pdf");

        //获取书签集合
        PdfBookmarkCollection bookmarkCollection = pdf.getBookmarks();

        //实例化StringBuilder类
        StringBuilder stringbuilder = new StringBuilder();

        //定义方法获取书签
        GetBookmarkTitle(bookmarkCollection, stringbuilder);

        //声明txt文件，并将获得的多级书签写入到文件.txt
        FileWriter writer;
        try {
            writer = new FileWriter("读取的书签.txt");
            writer.write(stringbuilder.toString());
            writer.flush();
        } catch (IOException e) {
            e.printStackTrace();
        }
        pdf.dispose();
    }
    //定义方法获取书签标题
static void GetBookmarkTitle(PdfBookmarkCollection bookmarkCollection, StringBuilder stringbuilder)
    {
        if (bookmarkCollection.getCount()> 0)
        {
            for(int i = 0 ; i< bookmarkCollection.getCount(); i++ )
            {
                PdfBookmark parentBookmark = bookmarkCollection.get(i);
                stringbuilder.append(parentBookmark.getTitle());
                //递归文档多级书签
                GetBookmarkTitle(parentBookmark, stringbuilder);
            }
        }
    }
}

书签读取结果：