Build a Java SpringBoot Digital Signature & Seal System with PageOffice

Introduction

The company needed a feature to sign and seal documents electronically. Digital signatures use cryptographic techniques to verify identity, ensure authenticity, integrity, and non‑repudiation of documents such as Word files, PDFs, emails, and macros. The demo simulates an OA system where Word documents flow through drafting, approval, sealing, and final publishing, using PageOffice for online editing and a custom seal verification engine that complies with China’s Electronic Signature Law and supports RSA.

Source Code and Deployment

Project Structure and Framework

The project is built with SpringBoot and Thymeleaf, managed by Maven. It provides both PC (PageOffice) and mobile (MobOffice) interfaces for document handling.

Controller Layer

@Controller
@RequestMapping("/mobile")
public class MobileOfficeController {
    @Value("${docpath}")
    private String docPath;
    @Value("${moblicpath}")
    private String moblicpath;
    @Autowired
    DocService m_docService;
    @RequestMapping("/opendoc")
    public void opendoc(HttpServletRequest request, HttpServletResponse response, HttpSession session, String type, String userName) throws Exception {
        // simplified logic for opening a document
    }
    @RequestMapping("/savedoc")
    public void savedoc(HttpServletRequest request, HttpServletResponse response) {
        FileSaver fs = new FileSaver(request, response);
        fs.saveToFile(docPath + fs.getFileName());
        fs.close();
    }
}

Service Layer

@Service
public class DocServiceImpl implements DocService {
    @Autowired
    DocMapper docMapper;
    @Override
    public Doc getDocById(int id) throws Exception {
        Doc doc = docMapper.getDocById(id);
        if (doc == null) {
            doc = new Doc();
        }
        return doc;
    }
    @Override
    public Integer addDoc(Doc doc) throws Exception {
        int id = docMapper.addDoc(doc);
        return id;
    }
    // other CRUD methods omitted for brevity
}

File Copy Utility

public class CopyFileUtil {
    // copy file from oldPath to newPath
    public static boolean copyFile(String oldPath, String newPath) throws Exception {
        // implementation omitted for brevity
    }
}

QR Code Utility

public class QRCodeUtil {
    private String codeText = "www.zhuozhengsoft.com";
    private BarcodeFormat barcodeFormat = BarcodeFormat.PDF_417;
    private int width = 400;
    private int height = 400;
    private String imageformat = "png";
    private int backColorRGB = 0xFFFFFFFF;
    private int codeColorRGB = 0xFF000000;
    private ErrorCorrectionLevel errorCorrectionLevel = ErrorCorrectionLevel.H;
    private String encodeType = "UTF-8";
    // getters, setters, and methods to generate QR code bytes omitted for brevity
}

Download and Deployment

Contact the author via WeChat (ID: fenggejava) and reply “盖章系统” to receive the source package.

After downloading, unzip the slndemodata.zip package to D:\ and import the slndemo project into IntelliJ IDEA.

Run the SpringBoot application; the demo will be accessible at http://localhost:8888/pc/login (default credentials: 张三 / 123456).

Feature Demonstration

Login to the system and start a new draft document.

Edit the document online; PageOffice prompts installation of the client plugin if missing.

Save the draft, submit for approval, and let different users (李总, 赵六, 王五) review, approve, and finally apply an electronic seal.

During sealing, the user must enter a valid username and password (e.g., 王五 / 123456) to select a personal seal.

After signing and sealing, the final document can be saved and published.