import org.bouncycastle.mail.smime.SMIMEException; //导入依赖的package包/类
private void processHTMLBodyWithBASE64Images(MimeMultipart multipart) throws ParserException,
        MessagingException, NoSuchAlgorithmException, SMIMEException, java.security.NoSuchProviderException {
    if (null != body && body.contains("base64")) {
        Parser parser = new Parser(body);
        NodeList nodeList = parser.parse(null);
        HtmlImageNodeVisitor htmlImageNodeVisitor = new HtmlImageNodeVisitor();
        nodeList.visitAllNodesWith(htmlImageNodeVisitor);
        body = nodeList.toHtml();

        addAllBase64ImagesToMimeMultipart(multipart, htmlImageNodeVisitor.getBase64Images());
    }
}
 

import org.bouncycastle.mail.smime.SMIMEException; //导入依赖的package包/类
private void addAllBase64ImagesToMimeMultipart(MimeMultipart multipart, Map<String, String> base64ImagesMap)
        throws MessagingException, NoSuchAlgorithmException, NoSuchProviderException, SMIMEException {
    for (String contentId : base64ImagesMap.keySet()) {
        MimeBodyPart imagePart = getImageMimeBodyPart(base64ImagesMap, contentId);
        imagePart = encryptMimeBodyPart(imagePart);
        multipart.addBodyPart(imagePart);
    }
}
 

import org.bouncycastle.mail.smime.SMIMEException; //导入依赖的package包/类
private MimeBodyPart encryptMimeBodyPart(MimeBodyPart mimeBodyPart) throws NoSuchAlgorithmException,
        NoSuchProviderException, SMIMEException {
    if (encryptMessage) {
        mimeBodyPart = gen.generate(mimeBodyPart, encryptionOID, BOUNCY_CASTLE_PROVIDER);
    }
    return mimeBodyPart;
}
 

import org.bouncycastle.mail.smime.SMIMEException; //导入依赖的package包/类
private MimeBodyPart decode2Mime(InputStream body) throws MessagingException, CMSException, SMIMEException, IOException {
    StringBuilder builder = new StringBuilder();
    builder.append("Content-Disposition: attachment; filename=\"smime.p7m\"\r\n");
    builder.append("Content-Type: application/pkcs7-mime; smime-type=enveloped-data; name=\"smime.p7m\"\r\n");
    builder.append("Content-Transfer-Encoding: base64\r\n\r\n");
    ByteArrayInputStream is = new ByteArrayInputStream(builder.toString().getBytes("utf-8"));
    MimeBodyPart mp = new MimeBodyPart(new SequenceInputStream(is, body));
    return decode2Mime(mp);
}