Enterprise Java Library for HIN (Hull Identification Number) OCR

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package com.structocr.examples;

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.util.Base64;
import com.google.gson.Gson;
import com.google.gson.JsonObject;

public class HinOcrClient {

    public static void main(String[] args) throws IOException, InterruptedException {
        String apiKey = "YOUR_API_KEY"; // Replace with your actual API key
        String imagePath = "path/to/boat_hull.jpg"; // Path to the marine image

        // 1. Read the image file and encode it to Base64
        String base64Image = encodeFileToBase64(imagePath);

        // 2. Construct the JSON payload
        JsonObject payload = new JsonObject();
        payload.addProperty("img", base64Image);
        String jsonPayload = payload.toString();

        // 3. Create the modern HTTP client
        HttpClient client = HttpClient.newHttpClient();

        // 4. Build the POST request to the StructOCR HIN endpoint
        HttpRequest request = HttpRequest.newBuilder()
                .uri(URI.create("https://api.structocr.com/v1/hin"))
                .header("x-api-key", apiKey)
                .header("Content-Type", "application/json")
                .POST(HttpRequest.BodyPublishers.ofString(jsonPayload))
                .build();

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

        // 6. Parse the deeply structured JSON response
        Gson gson = new Gson();
        JsonObject jsonResponse = gson.fromJson(response.body(), JsonObject.class);

        // 7. Safely extract the HIN and parsed attributes
        if (jsonResponse.has("is_valid") && jsonResponse.get("is_valid").getAsBoolean()) {
            String hin = jsonResponse.get("hin_number").getAsString();
            String confidence = jsonResponse.get("confidence").getAsString();
            
            System.out.println("✅ Extracted HIN: " + hin + " (Confidence: " + confidence + ")");

            // Access the 'parsed' object for deep data
            JsonObject parsed = jsonResponse.getAsJsonObject("parsed");
            String manufacturer = parsed.get("manufacturer_code").getAsString();
            String year = parsed.get("model_year").getAsString();
            
            System.out.println("Manufacturer Code: " + manufacturer);
            System.out.println("Model Year: " + year);

        } else {
            String error = jsonResponse.has("validation_error") && !jsonResponse.get("validation_error").isJsonNull() 
                ? jsonResponse.get("validation_error").getAsString() 
                : "Unknown error or invalid HIN.";
            System.out.println("❌ Failed: " + error);
        }
    }

    private static String encodeFileToBase64(String filePath) throws IOException {
        Path path = Path.of(filePath);
        byte[] fileContent = Files.readAllBytes(path);
        return Base64.getEncoder().encodeToString(fileContent);
    }
}