Java Driver's License OCR via a Simple REST API

import java.io.IOException;
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.nio.file.Files;
import java.nio.file.Path;
import java.time.Duration;
import java.util.Base64;

public class StructOcrApiExample {

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    // 👉 https://structocr.com/register

    private static final String API_KEY = "YOUR_API_KEY_HERE";
    private static final String API_ENDPOINT = "https://api.structocr.com/v1/driver-license";

    public static void main(String[] args) {
        // Replace this with your actual file path
        String imagePath = "license.jpg";

        try {
            // 1. Read image file and encode to Base64
            Path path = Path.of(imagePath);
            if (!Files.exists(path)) {
                System.err.println("Error: File not found at " + path.toAbsolutePath());
                return;
            }
            
            byte[] imageBytes = Files.readAllBytes(path);
            String base64Image = Base64.getEncoder().encodeToString(imageBytes);

            // 2. Construct JSON Payload (Dependency-free approach)
            // For production systems, we recommend using Jackson or Gson.
            String jsonPayload = "{\"img\": \"" + base64Image + "\"}";

            // 3. Create HttpClient
            HttpClient client = HttpClient.newBuilder()
                    .version(HttpClient.Version.HTTP_1_1)
                    .connectTimeout(Duration.ofSeconds(10))
                    .build();

            // 4. Build Request
            // Important: 'x-api-key' is required in the header
            HttpRequest request = HttpRequest.newBuilder()
                    .uri(URI.create(API_ENDPOINT))
                    .header("Content-Type", "application/json")
                    .header("x-api-key", API_KEY)
                    .POST(HttpRequest.BodyPublishers.ofString(jsonPayload))
                    .build();

            System.out.println("Sending request to " + API_ENDPOINT + "...");

            // 5. Send Request
            HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());

            // 6. Output Result
            if (response.statusCode() == 200) {
                System.out.println("✅ Extraction Successful!");
                // Printing raw JSON. Use a JSON parser to extract specific fields like 'document_number'.
                System.out.println(response.body());
            } else {
                System.err.println("❌ API Error: " + response.statusCode());
                System.err.println(response.body());
            }

        } catch (IOException | InterruptedException e) {
            System.err.println("Request failed: " + e.getMessage());
            Thread.currentThread().interrupt();
        }
    }
}