Implementing Java QR Code Signing with GroupDocs.Signature for Java

Introduction

Enhance the security of your digital documents by embedding QR codes into your Java applications. Leveraging GroupDocs.Signature for Java allows you to ensure document authenticity and traceability effectively. This guide will walk you through creating custom data signatures, configuring QR code signing options, and securing your documents with robust encryption.

What You’ll Learn:

  • How to create a custom data signature class using GroupDocs.Signature
  • Configuring QR code sign options in Java applications
  • Signing documents with QR codes and applying custom encryption

Let’s dive into the prerequisites and start integrating this functionality into your projects!

Prerequisites

Before we begin, ensure that you have set up the necessary libraries and dependencies in your development environment.

Required Libraries and Versions

To implement GroupDocs.Signature for Java, include the following dependency:

Maven

<dependency>
    <groupId>com.groupdocs</groupId>
    <artifactId>groupdocs-signature</artifactId>
    <version>23.12</version>
</dependency>

Gradle

implementation 'com.groupdocs:groupdocs-signation:23.12'

You can also download the latest version directly from GroupDocs.Signature for Java releases.

Environment Setup Requirements

  • Ensure you have a working Java Development Kit (JDK) installed.
  • Set up your Integrated Development Environment (IDE), such as IntelliJ IDEA or Eclipse.

Knowledge Prerequisites

  • Basic understanding of Java programming and object-oriented concepts.
  • Familiarity with handling dependencies using Maven or Gradle.

Setting Up GroupDocs.Signature for Java

To get started, set up GroupDocs.Signature in your project by following the installation instructions above to include it in your build configuration.

License Acquisition Steps

GroupDocs offers different licensing options:

  • Free Trial: Test all features without limitations.
  • Temporary License: Obtain a license for evaluation purposes.
  • Purchase: Acquire a full license for commercial use.

After downloading, initialize GroupDocs.Signature like this:

import com.groupdocs.signature.Signature;

class InitializeGroupDocs {
    public static void main(String[] args) {
        Signature signature = new Signature("path/to/your/document");
        // You can now start using the signature object to work with documents.
    }
}

Implementation Guide

Let’s break down the implementation process into manageable sections, focusing on key features.

Custom Data Signature Class

Overview

Create a custom class to store signature data such as ID, author, signing date, and additional factors. This ensures you have all necessary metadata encapsulated within your signatures.

Step-by-Step Implementation

Define the DocumentSignatureData Class

import com.groupdocs.signature.domain.extensions.serialization.FormatAttribute;
import java.util.Date;
import java.math.BigDecimal;

class DocumentSignatureData {
    @FormatAttribute(propertyName = "SignID")
    public String ID; // Unique identifier for the signature
    
    public String getID() { return ID; }
    public void setID(String value) { ID = value; }
    
    @FormatAttribute(propertyName = "SAuth")
    public final String Author; // Author of the document
    
    public final String getAuthor() { return Author; }
    public final void setAuthor(String value) { Author = value; }
    
    @FormatAttribute(propertyName = "SDate", propertyFormat = "yyyy-MM-dd")
    public final Date Signed = new Date(); // Signing date and time
    
    public final Date getSigned() { return Signed; }
    public final void setSigned(Date value) { Signed = value; }
    
    @FormatAttribute(propertyName = "SDFact", propertyFormat = "N2")
    public final BigDecimal DataFactor = new BigDecimal(0.01); // Additional data factor for signature
    
    public final BigDecimal getDataFactor() { return DataFactor; }
    public final void setDataFactor(BigDecimal value) { DataFactor = value; }
}

Explanation:

  • FormatAttribute: Annotates properties to customize serialization.
  • Properties: Capture essential details like the unique ID, author name, signing date, and data factor.

QR Code Sign Options Configuration

Overview

Configure QR code sign options to define how your QR codes will appear on documents, including size, alignment, and padding.

Step-by-Step Implementation

Define the QrCodeSignOptionsConfig Class

import com.groupdocs.signature.domain.enums.HorizontalAlignment;
import com.groupdocs.signature.domain.enums.VerticalAlignment;
import com.groupdocs.signature.domain.qrcodes.QrCodeTypes;
import com.groupdocs.signature.domain.Padding;
import com.groupdocs.signature.options.sign.QrCodeSignOptions;

class QrCodeSignOptionsConfig {
    public static QrCodeSignOptions setupQrCodeSignOptions(DocumentSignatureData documentSignature) {
        QrCodeSignOptions options = new QrCodeSignOptions();
        
        // Serialize the custom data object into QR code
        options.setData(documentSignature);
        
        // Specify QR code type
        options.setEncodeType(QrCodeTypes.QR);
        
        // Configure padding for alignment
        Padding padding = new Padding();
        padding.setRight(10); // Right padding in pixels
        padding.setBottom(10); // Bottom padding in pixels
        options.setMargin(padding);
        
        // Define size and position of the QR code
        options.setHeight(100);
        options.setWidth(100);
        options.setVerticalAlignment(VerticalAlignment.Bottom);
        options.setHorizontalAlignment(HorizontalAlignment.Right);
        
        return options;
    }
}

Explanation:

  • QrCodeSignOptions: Manages how the QR code is displayed, including its size and position.
  • Padding: Adjusts alignment within the document.

Document Signing with QR Code and Custom Encryption

Overview

Combine QR codes and custom encryption to sign documents securely. This ensures data integrity and confidentiality.

Step-by-Step Implementation

Sign a Document with QR Code

import com.groupdocs.signature.Signature;
import com.groupdocs.signature.domain.extensions.encryption.IDataEncryption;
import com.groupdocs.signature.exception.GroupDocsSignatureException;

import java.util.UUID;

class SignDocumentWithQRCode {
    public static void signDocument(String filePath, String outputFilePath) throws Exception {
        try {
            Signature signature = new Signature(filePath);

            // Custom XOR encryption strategy
            IDataEncryption encryption = new CustomXOREncryption();

            // Configure the custom document signature data object
            DocumentSignatureData documentSignature = new DocumentSignatureData();
            documentSignature.setID(UUID.randomUUID().toString());
            documentSignature.setAuthor(System.getenv("USERNAME"));
            documentSignature.setSigned(new Date());
            documentSignature.setDataFactor(new BigDecimal("11.22"));

            // Setup QR-Code options
            QrCodeSignOptions options = QrCodeSignOptionsConfig.setupQrCodeSignOptions(documentSignature);

            // Apply encryption to the data within the QR code
            options.setDataEncryption(encryption);

            // Sign and save the document
            signature.sign(outputFilePath, options);
        } catch (Exception e) {
            throw new GroupDocsSignatureException(e.getMessage());
        }
    }
}

Explanation:

  • CustomXOREncryption: Implements a custom encryption strategy for securing QR code data.
  • UUID: Generates a unique identifier for each signature.