LPR/VMM API in Android (Java)

The content outlines a step-by-step guide to implement OkHttp in an Android application. It details adding the necessary dependency, coding a MainActivity that constructs and sends a GET request to an API for object detection, and logging the response or errors. The result is a functional interaction with an ANPR service.

Step 1: Add OkHttp Dependency #

Add this to your build.gradle (Module: app):

dependencies {
    implementation 'com.squareup.okhttp3:okhttp:4.12.0'
}

Step 2: Android Code Example #

import android.os.Bundle;
import android.util.Log;
import androidx.appcompat.app.AppCompatActivity;
import java.io.IOException;
import java.net.URLEncoder;
import okhttp3.Call;
import okhttp3.Callback;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;

public class MainActivity extends AppCompatActivity {

    private static final String TAG = "AnprAPI";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        String imageUrl = "https://example.com/car.jpg";
        String apiKey = "your_api_key";
        String ga = "your_ga_value";

        try {
            String url = "https://your-api-endpoint.com/ObjectDetection"
                    + "?Image_url=" + URLEncoder.encode(imageUrl, "UTF-8")
                    + "&Api_key=" + URLEncoder.encode(apiKey, "UTF-8")
                    + "&GA=" + URLEncoder.encode(ga, "UTF-8")
                    + "&Detect_license_plate=true"
                    + "&Read_license_plate=true";

            OkHttpClient client = new OkHttpClient();
            Request request = new Request.Builder()
                    .url(url)
                    .build();

            client.newCall(request).enqueue(new Callback() {
                @Override
                public void onFailure(Call call, IOException e) {
                    Log.e(TAG, "Request Failed: " + e.getMessage());
                }

                @Override
                public void onResponse(Call call, Response response) throws IOException {
                    if (response.isSuccessful()) {
                        final String responseBody = response.body().string();
                        Log.d(TAG, "Response: " + responseBody);
                    } else {
                        Log.e(TAG, "Error: " + response.code());
                    }
                }
            });
        } catch (Exception e) {
            Log.e(TAG, "Exception: " + e.getMessage());
        }
    }
}

Result: This sends a GET request to the API and logs the response from the ANPR service.

Let me know if you want to do this in Kotlin, or if the endpoint is actually a POST request.

Required Dependencies #

To ensure compatibility and support for HTTP communication and backward-compatible UI components, please add the following dependencies to your build.gradle (app-level):

// HTTP client for making network requests
implementation 'com.squareup.okhttp3:okhttp:4.12.0'

// AndroidX AppCompat for backward compatibility
def appcompat_version = "1.7.1"
implementation "androidx.appcompat:appcompat:$appcompat_version"

// For loading and tinting drawables on older Android versions
implementation "androidx.appcompat:appcompat-resources:$appcompat_version"