如何在 Java 中使用条形码和二维码为文件添加数字签名

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

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

import com.groupdocs.signature.Signature;

public class InitializeSignature {
    public static void main(String[] args) {
        Signature signature = new Signature("your-document-path");
        // Additional setup and usage here...
    }
}

import com.groupdocs.signature.Signature;

final Signature signature = new Signature("path/to/your/archive.tar");

import com.groupdocs.signature.options.sign.BarcodeSignOptions;
import com.groupdocs.signature.domain.barcodes.BarcodeTypes;

BarcodeSignOptions bcOptions = new BarcodeSignOptions("12345678", BarcodeTypes.Code128);
bcOptions.setLeft(100);  // X position in pixels
bcOptions.setTop(100);   // Y position in pixels

bcOptions.setWidth(200);        // Barcode width in pixels
bcOptions.setHeight(50);        // Barcode height in pixels
bcOptions.setForeColor(Color.BLACK);  // Barcode color
bcOptions.setBackgroundColor(Color.WHITE);  // Background color

import com.groupdocs.signature.domain.SignResult;

String outputFilePath = "output/path/SignWithBarcode/archive_signed.tar";
SignResult signResult = signature.sign(outputFilePath, bcOptions);

final Signature signature = new Signature("path/to/your/archive.tar");

import com.groupdocs.signature.options.sign.QrCodeSignOptions;
import com.groupdocs.signature.domain.qrcodes.QrCodeTypes;

QrCodeSignOptions qrOptions = new QrCodeSignOptions("12345678", QrCodeTypes.QR);
qrOptions.setLeft(400);  // X position
qrOptions.setTop(400);   // Y position

String verificationData = "{\"version\":\"1.0\",\"timestamp\":\"2025-01-02T10:30:00Z\",\"user\":\"john.doe\"}";
QrCodeSignOptions qrOptions = new QrCodeSignOptions(verificationData, QrCodeTypes.QR);

String outputFilePath = "output/path/SignWithQRCode/archive_signed.tar";
SignResult signResult = signature.sign(outputFilePath, qrOptions);

final Signature signature = new Signature("path/to/your/archive.tar");

import java.util.ArrayList;
import java.util.List;

// Set up barcode (reusing from earlier example)
BarcodeSignOptions bcOptions = new BarcodeSignOptions("12345678", BarcodeTypes.Code128);
bcOptions.setLeft(100);
bcOptions.setTop(100);

// Set up QR code (different position to avoid overlap)
QrCodeSignOptions qrOptions = new QrCodeSignOptions("12345678", QrCodeTypes.QR);
qrOptions.setLeft(400);
qrOptions.setTop(400);

// Combine them
List<com.groupdocs.signature.options.sign.SignOptions> listOptions = new ArrayList<>();
listOptions.add(bcOptions);
listOptions.add(qrOptions);

String outputFilePath = "output/path/SignWithMultipleSignatures/archive_signed.tar";
SignResult signResult = signature.sign(outputFilePath, listOptions);

String releaseData = String.format(
    "{\"version\":\"%s\",\"buildDate\":\"%s\",\"sha256\":\"%s\"}",
    version, buildDate, checksum
);

String backupId = String.format("SRV01-%s", LocalDateTime.now().format(formatter));
BarcodeSignOptions bcOptions = new BarcodeSignOptions(backupId, BarcodeTypes.Code128);

String trackingUrl = "https://verify.yourcompany.com/track/" + uniqueId;
QrCodeSignOptions qrOptions = new QrCodeSignOptions(trackingUrl, QrCodeTypes.QR);

// Always verify the signing succeeded
SignResult result = signature.sign(outputFilePath, bcOptions);
if (result.getSucceeded().size() > 0) {
    System.out.println("Signature added successfully at: " + outputFilePath);
} else {
    System.err.println("Signing failed: " + result.getFailed());
}

// Use absolute paths to avoid confusion
String absolutePath = new File(outputFilePath).getAbsolutePath();

java -Xmx2G -jar your-application.jar

// For very large files, consider signing metadata separately
// rather than embedding in the TAR itself

// Bad: Too much data for Code128
BarcodeSignOptions bcOptions = new BarcodeSignOptions(veryLongString, BarcodeTypes.Code128);

// Good: Use QR code instead
QrCodeSignOptions qrOptions = new QrCodeSignOptions(veryLongString, QrCodeTypes.QR);

import com.groupdocs.signature.License;

License license = new License();
license.setLicense("path/to/GroupDocs.Signature.lic");

// Now create signatures
Signature signature = new Signature("document.tar");

bcOptions.setLeft(100);  // 100 pixels from left edge
bcOptions.setTop(100);   // 100 pixels from top edge

// If you need percentage-based positioning:
bcOptions.setHorizontalAlignment(HorizontalAlignment.Center);
bcOptions.setVerticalAlignment(VerticalAlignment.Center);

@RestController
@RequestMapping("/api/signature")
public class SignatureController {
    
    @PostMapping("/sign")
    public ResponseEntity<SignatureResponse> signFile(
            @RequestParam("file") MultipartFile file,
            @RequestParam("signatureType") String type) {
        
        try {
            // Save uploaded file temporarily
            File tempFile = File.createTempFile("upload-", ".tar");
            file.transferTo(tempFile);
            
            // Sign based on type
            Signature signature = new Signature(tempFile.getAbsolutePath());
            
            SignOptions options = type.equals("barcode") 
                ? createBarcodeOptions() 
                : createQROptions();
            
            String outputPath = generateOutputPath();
            SignResult result = signature.sign(outputPath, options);
            
            // Return signed file
            return ResponseEntity.ok(new SignatureResponse(outputPath, result));
            
        } catch (Exception e) {
            return ResponseEntity.status(500).body(null);
        }
    }
}

public class BatchSigner {
    
    public void signArchiveBatch(List<File> archives) {
        ExecutorService executor = Executors.newFixedThreadPool(4);
        
        archives.forEach(archive -> {
            executor.submit(() -> {
                try {
                    signSingleArchive(archive);
                } catch (Exception e) {
                    logger.error("Failed to sign: " + archive.getName(), e);
                }
            });
        });
        
        executor.shutdown();
        executor.awaitTermination(1, TimeUnit.HOURS);
    }
    
    private void signSingleArchive(File archive) throws Exception {
        Signature signature = new Signature(archive.getAbsolutePath());
        // ... signing logic
    }
}

@Component
public class ArchiveCreatedListener {
    
    @EventListener
    public void onArchiveCreated(ArchiveCreatedEvent event) {
        CompletableFuture.runAsync(() -> {
            signArchive(event.getFilePath());
        });
    }
    
    private void signArchive(String filePath) {
        // ... signing logic
    }
}

// Bad: Creating multiple instances for same file
Signature sig1 = new Signature("file.tar");
Signature sig2 = new Signature("file.tar");  // Loads again!

// Good: Reuse the instance
try (Signature signature = new Signature("file.tar")) {
    signature.sign(output1, options1);
    signature.sign(output2, options2);  // Same instance, different outputs
}

License license = new License();
if (!license.isLicensed()) {
    logger.warn("Running in trial mode - features may be limited");
}

try {
    signature.sign(outputPath, options);
} catch (Exception e) {
    logger.error("Signature failed", e);
    // Don't just swallow exceptions - log or re-throw
    throw new SignatureException("Failed to sign document", e);
}

// Bad: Meaningless ID
new BarcodeSignOptions("12345678", BarcodeTypes.Code128);

// Good: Self-documenting data
String signatureData = String.format("DOC-%s-%s", 
    docType, 
    LocalDateTime.now().format(DateTimeFormatter.ISO_DATE_TIME)
);
new BarcodeSignOptions(signatureData, BarcodeTypes.Code128);

String qrData = String.format(
    "{\"v\":\"1.0\",\"type\":\"archive\",\"timestamp\":\"%s\"}", 
    timestamp
);

Signature signature = new Signature("signed-document.tar");
BarcodeSearchOptions searchOptions = new BarcodeSearchOptions();
List<BarcodeSignature> signatures = signature.search(BarcodeSignature.class, searchOptions);

bcOptions.setForeColor(Color.BLUE);
bcOptions.setBackgroundColor(Color.YELLOW);
bcOptions.setBorder(new Border());
bcOptions.getBorder().setColor(Color.RED);
bcOptions.getBorder().setWeight(2);