如何通过 Java 应用程序添加或删除 PDF 中的附件

<repositories>        <repository>            <id>com.e-iceblue</id>            <url>https://repo.e-iceblue.cn/repository/maven-public/</url>        </repository>    </repositories><dependencies>    <dependency>        <groupId>e-iceblue</groupId>        <artifactId>spire.pdf.free</artifactId>        <version>5.1.0</version>    </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();    }}