我已经研究数字签名功能几天了，现在一切正常，是时候尝试在所有页面上打印邮票了，但我做得不太好......
试图给出一个快速的简历，以显示邮票我所做的是创建 PdfStamper、PdfSignatureAppearance 和一个 Rectangle，然后调用
appearance.setVisibleSignature(rectangle, 1, "SIGNATURE")
上面的第二个参数“1”是我想要显示图章的页码，现在可以为 1，因为我试图为了在其他页面中显示图章而创建 PdfStamper、PdfSignatureAppearance 和的其他实例一个矩形，但将其设置为第 2 页。如果它有效，我会将其放入循环中并不断更改页面参数。
但为什么没效果？？？好吧，在接近尾声时，我调用 MakeSignature 的方法，并且在参数中我必须传递我创建的外观之一，如果我多次调用它，则签名仅出现在与我传递给它的最后一个外观相关的页面上。
例如：
MakeSignature.signDetached(appearance2, digest, pks, chain, null, null, null, 0, CryptoStandard.CMS);
MakeSignature.signDetached(appearance, digest, pks, chain, null, null, null, 0, CryptoStandard.CMS);
印章将仅显示在第一页上。
也许我可以在这里得到一些帮助？？？
整个事情就是这样：
public String signPdfFirstTime(String src, String dest, PrivateKey pk, Certificate[] chain, String providerName, String conteudoBase64, X509Certificate cert, String alias) throws IOException, DocumentException, GeneralSecurityException
{
byte[] conteudoBinario = Base64.decode(conteudoBase64);
FileOutputStream fos = new FileOutputStream(path + File.separator + src);
fos.write(conteudoBinario);
fos.close();
File f = new File(path + File.separator + src);
FileInputStream in = new FileInputStream(f);
PdfReader reader = new PdfReader(in);
int qtypages = reader.getNumberOfPages();
FileOutputStream os = new FileOutputStream(path + File.separator + dest);
PdfStamper stamper = PdfStamper.createSignature(reader, os, '\0');
// Creating the appearance
PdfSignatureAppearance appearance = stamper.getSignatureAppearance();
Rectangle rectangle = new Rectangle(550, 50, 610, 500);// funciona vertical
appearance.setVisibleSignature(rectangle, 1, "SIGNATURE");
//Here I build a custom message...nothing relevant
StringBuilder stampMessage = new StringBuilder();
stampMessage.append("...");
stampMessage.append(alias);
stampMessage.append(" - ");
// customize appearance layer 2 to display text vertically
PdfTemplate layer2 = appearance.getLayer(2);
layer2.transform(new AffineTransform(0, 1, -1, 0, rectangle.getWidth(), 0));
Font font = new Font();
font.setColor(BaseColor.BLACK);
ColumnText ct2 = new ColumnText(layer2);
ct2.setRunDirection(PdfWriter.RUN_DIRECTION_NO_BIDI);
ct2.setSimpleColumn(new Phrase(stampMessage.toString(), font), 0, 0, rectangle.getHeight(), rectangle.getWidth(), 15, Element.ALIGN_LEFT);
ct2.go();
appearance.setCertificate(cert);
//Here starts where I tried to make a second stamp to show in the page 2
FileOutputStream fos2 = new FileOutputStream(path + File.separator + src);
fos2.write(conteudoBinario);
fos2.close();
File f2 = new File(path + File.separator + src);
FileInputStream in2 = new FileInputStream(f2);
PdfReader reader2 = new PdfReader(in2);
FileOutputStream os2 = new FileOutputStream(path + File.separator + dest);
PdfStamper stamper2 = PdfStamper.createSignature(reader2, os2, '\0');
// Creating the appearance
PdfSignatureAppearance appearance2 = stamper2.getSignatureAppearance();
Rectangle rectangle2 = new Rectangle(550, 50, 610, 500);// funciona vertical
appearance2.setVisibleSignature(rectangle2, 3, "ASSINATURA2");
//Cria a msg que aparece na estampa
StringBuilder stampMessage2 = new StringBuilder();
stampMessage2.append(" - ");
PdfTemplate layer22 = appearance.getLayer(2);
layer22.transform(new AffineTransform(0, 1, -1, 0, rectangle2.getWidth(), 0));
Font font2 = new Font();
font2.setColor(BaseColor.BLACK);
ColumnText ct22 = new ColumnText(layer22);
ct22.setRunDirection(PdfWriter.RUN_DIRECTION_NO_BIDI);
ct22.setSimpleColumn(new Phrase(stampMessage2.toString(), font2), 0, 0, rectangle2.getHeight(), rectangle2.getWidth(), 15, Element.ALIGN_LEFT);
ct22.go();
appearance2.setCertificate(cert);
// Creating the signature
ExternalSignature pks = new PrivateKeySignature(pk, DigestAlgorithms.SHA256, providerName);
ExternalDigest digest = new BouncyCastleDigest();
List<CrlClient> crlList = new ArrayList<CrlClient>();
crlList.add(new CrlClientOnline());
LtvVerification v = stamper.getLtvVerification();
LtvVerification v2 = stamper2.getLtvVerification();
OcspClient ocspClient = new OcspClientBouncyCastle();
String url = CertificateUtil.getCRLURL(cert);
CertificateFactory cf = CertificateFactory.getInstance("X.509");
X509CRL crl = (X509CRL) cf.generateCRL(new URL(url).openStream());
System.out.println("CRL valid until: " + crl.getNextUpdate());
System.out.println("Certificate revoked: " + crl.isRevoked(chain[0]));
if (crl.isRevoked(chain[0])) {
throw new GeneralSecurityException("CERTIFICADO REVOGADO!");
}
else {
MakeSignature.processCrl(cert, crlList);
MakeSignature.signDetached(appearance2, digest, pks, chain, null, null, null, 0, CryptoStandard.CMS);
MakeSignature.signDetached(appearance, digest, pks, chain, null, null, null, 0, CryptoStandard.CMS);
os.close();
byte[] b = this.read(f);
return Base64.encodeBytes(b);
}
}
