如何通过Java应用程序添加或删除 PDF 中的附件

<repositories>
        <repository>
            <id>com.e-iceblueid>
            <url>https://repo.e-iceblue.cn/repository/maven-public/
        repository>
    repositories>
<dependencies>
    <dependency>
        <groupId>e-icebluegroupId>
        <artifactId>spire.pdf.freeartifactId>
        <version>5.1.0version>
    dependency>
dependencies>

import com.spire.pdf.PdfDocument;
import com.spire.pdf.attachments.PdfAttachment;

public class AttachFilesToPdf {

    public static void main(String[] args) {

        //创建一个 PdfDocument 对象
        PdfDocument doc = new PdfDocument();

        //加载 PDF 文档
        doc.loadFromFile("什么是AI数字人.pdf");

        //基于外部文件创建 PdfAttachment 对象
        PdfAttachment attachment = new PdfAttachment("到场嘉宾名单.xlsx");

        //将附件添加到 PDF
        doc.getAttachments().add(attachment);

        //保存文件
        doc.saveToFile("添加附件.pdf");
    }
}

import com.spire.pdf.PdfPageBase;
import com.spire.pdf.annotations.*;
import com.spire.pdf.graphics.*;
import com.spire.pdf.PdfDocument;

import java.awt.*;
import java.awt.geom.Dimension2D;
import java.awt.geom.Rectangle2D;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;

public class AnnotationAttachment {

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

        //创建一个 PdfDocument 对象
        PdfDocument doc = new PdfDocument();

        //加载 PDF 文档
        doc.loadFromFile("什么是AI数字人1.pdf");

        //获取特定页面
        PdfPageBase page = doc.getPages().get(0);

        //在 PDF 上绘制标签
        String label = "AI数字人详情介绍见附件:";
        PdfTrueTypeFont font = new PdfTrueTypeFont(new Font("宋体", Font.PLAIN, 13));
        double x = 35;
        double y = doc.getPages().get(0).getActualSize().getHeight() - 270;
        page.getCanvas().drawString(label, font, PdfBrushes.getRed(), x, y);

        //附加文件作为注释
        String filePath = "AI数字人详情介绍.pptx";
        byte[] data = toByteArray(filePath);
        Dimension2D size = font.measureString(label);
        Rectangle2D bound = new Rectangle2D.Float((float) (x + size.getWidth() + 5), (float) y, 10, 15);
        PdfAttachmentAnnotation annotation = new PdfAttachmentAnnotation(bound, filePath, data);
        annotation.setColor(new PdfRGBColor(new Color(0, 128, 128)));
        annotation.setFlags(PdfAnnotationFlags.Default);
        annotation.setIcon(PdfAttachmentIcon.Graph);
        annotation.setText("单击此处打开文件");
        page.getAnnotationsWidget().add(annotation);

        //保存文件
        doc.saveToFile("添加注释附件.pdf");
    }
    //将文件转换为字节数组
    public static byte[] toByteArray(String filePath) throws IOException {

        File file = new File(filePath);
        long fileSize = file.length();
        if (fileSize > Integer.MAX_VALUE) {
            System.out.println("文件过大...");
            return null;
        }
        FileInputStream fi = new FileInputStream(file);
        byte[] buffer = new byte[(int) fileSize];
        int offset = 0;
        int numRead = 0;
        while (offset < buffer.length
                && (numRead = fi.read(buffer, offset, buffer.length - offset)) >= 0) {
            offset += numRead;
        }

        if (offset != buffer.length) {
            throw new IOException("无法完全读取文件 "
                    + file.getName());
        }
        fi.close();
        return buffer;
    }
}

import com.spire.pdf.PdfDocument;
import com.spire.pdf.attachments.PdfAttachmentCollection;

public class RemoveAttachments {

    public static void main(String[] args) {

        //创建一个 PdfDocument 对象
        PdfDocument doc = new PdfDocument();

        //加载 PDF 文档
        doc.loadFromFile("添加附件.pdf");

        //获取附件集合，不包含注释附件
        PdfAttachmentCollection attachments = doc.getAttachments();

        //删除所有附件
        attachments.clear();

        //删除指定附件
        //attachments.removeAt(0);

        //保存文件
        doc.saveToFile("删除附件.pdf");
        doc.close();
    }
}

import com.spire.pdf.PdfDocument;
import com.spire.pdf.annotations.PdfAnnotation;
import com.spire.pdf.annotations.PdfAnnotationCollection;
import com.spire.pdf.annotations.PdfAttachmentAnnotationWidget;

public class RemoveAnnotationAttachments {

    public static void main(String[] args) {

        //创建一个 PdfDocument 对象
        PdfDocument doc = new PdfDocument();

        //加载 PDF 文档
        doc.loadFromFile("添加注释附件.pdf");

        //遍历文档中的页面
        for (int i = 0; i < doc.getPages().getCount(); i++) {

            //获取注释集合
            PdfAnnotationCollection annotationCollection = doc.getPages().get(i).getAnnotationsWidget();

            //循环遍历注释
            for (Object annotation: annotationCollection) {

                //确定注释是否为 PdfAttachmentAnnotationWidget 的实例
                if (annotation instanceof PdfAttachmentAnnotationWidget){

                    //删除注释附件
                    annotationCollection.remove((PdfAnnotation) annotation);
                }
            }
        }

        //保存文件
        doc.saveToFile("删除注释附件.pdf");
        doc.close();
    }
}