Java实现添加、验证PDF数字签名的方法示例

import com.spire.pdf.*;
import com.spire.pdf.graphics.PdfImage;
import com.spire.pdf.graphics.PdfTrueTypeFont;
import com.spire.pdf.security.GraphicMode;
import com.spire.pdf.security.PdfCertificate;
import com.spire.pdf.security.PdfCertificationFlags;
import com.spire.pdf.security.PdfSignature;

import java.awt.*;
import java.awt.geom.Point2D;
import java.awt.geom.Rectangle2D;

public class AddCertificate {
    public static void main(String[]args){
        //加载PDF文档
        PdfDocument doc = new PdfDocument();
        doc.loadFromFile("test.pdf");

        //加载pfx证书，及证书秘钥
        PdfCertificate cert = new PdfCertificate("Cermia.pfx","123654yes!");

        //添加数字签名到指定页面，并设置其位置和大小
        PdfSignature signature = new PdfSignature(doc, doc.getPages().get(2), cert, "MySignature");
        Rectangle2D rect = new Rectangle2D.Float();
        rect.setFrame(new Point2D.Float((float) doc.getPages().get(0).getActualSize().getWidth() - 340, (float) doc.getPages().get(0).getActualSize().getHeight() - 230), new Dimension(280, 150));
        signature.setBounds(rect);

        //设置签名为图片加文本模式
        signature.setGraphicMode(GraphicMode.Sign_Image_And_Sign_Detail);

        //设置签名的内容
        signature.setNameLabel("签字者：");
        signature.setName("Mia");
        signature.setContactInfoLabel("联系电话：");
        signature.setContactInfo("02881705109");
        signature.setDateLabel("日期：");
        signature.setDate(new java.util.Date());
        signature.setLocationInfoLabel("地点：");
        signature.setLocationInfo("成都");
        signature.setReasonLabel("原因：");
        signature.setReason("文档所有者");
        signature.setDistinguishedNameLabel("DN: ");
        signature.setDistinguishedName(signature.getCertificate().get_IssuerName().getName());
        signature.setSignImageSource(PdfImage.fromFile("sign.png"));

        //设置签名的字体
        signature.setSignDetailsFont(new PdfTrueTypeFont(new Font("Arial Unicode MS", Font.PLAIN, 9)));

        //设置文档权限为禁止更改
        signature.setDocumentPermissions(PdfCertificationFlags.Forbid_Changes);
        signature.setCertificated(true);

        //保存文档
        doc.saveToFile("AddSignature.pdf");
        doc.close();
    }
}

import com.spire.pdf.*;
import com.spire.pdf.security.PdfSignature;
import com.spire.pdf.widget.PdfFormFieldWidgetCollection;
import com.spire.pdf.widget.PdfFormWidget;
import com.spire.pdf.widget.PdfSignatureFieldWidget;

import javax.swing.*;

public class ValidateSignature {
    public static void main(String[]args){
        //创建PdfDocument实例
        PdfDocument doc = new PdfDocument();
        //加载含有签名的PDF文件
        doc.loadFromFile("SignnedFile.pdf");

        //获取域集合
        PdfFormWidget pdfFormWidget = (PdfFormWidget) doc.getForm();
        PdfFormFieldWidgetCollection pdfFormFieldWidgetCollection = pdfFormWidget.getFieldsWidget();

        //遍历域
        for (int i = 0; i < pdfFormFieldWidgetCollection.getCount(); i++) {
            //判定是否为签名域
            if (pdfFormFieldWidgetCollection.get(i) instanceof PdfSignatureFieldWidget) {
                //获取签名域
                PdfSignatureFieldWidget signatureFieldWidget = (PdfSignatureFieldWidget) pdfFormFieldWidgetCollection.get(i);
                //获取签名
                PdfSignature signature = signatureFieldWidget.getSignature();

                //判定签名是否有效
                boolean result = signature.verifySignature();
                if (result) {
                    String str1 =" 有效签名";
                    JOptionPane.showMessageDialog(null,str1);
                } else {
                    String str2 =" 无效签名";
                    JOptionPane.showMessageDialog(null,str2);
                }
            }
        }

    }
}