Can-Bus with Android Studio

Question

I'm beginner new and i've done a lot of research on this subject but i couldn't find a helpful resource. I want to create an application on Android Studio that listens to Can-Bus line and runs only in the background without a user interface. I need to use J1939 library for this, but i don't know how to ensure communication. I would be glad if you help. Thank you.

CanBusService.java;

package com.example.j1939_android3;
import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.util.Log;

public class CanBusService extends Service {

    @Override
    public void onCreate() {
        super.onCreate();
        Log.d("CanBusService", "Service created");
        // Initialize CAN bus communication here
        // Add your CAN bus communication logic
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Log.d("CanBusService", "Service started");
        // Start listening to the CAN bus
        startListeningToCanBus();
        return START_STICKY;
    }

    private void startListeningToCanBus() {
        // Implement CAN bus listening logic here
        // This method will run in the background
    }

    @Override
    public IBinder onBind(Intent intent) {
        // Return null because this service is not meant to be bound
        return null;
    }
}

CanBusHandler.java:

package com.example.j1939_android3;

import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.util.Log;

public class CanBusService extends Service {

    @Override
    public void onCreate() {
        super.onCreate();
        Log.d("CanBusService", "Service created");
        // Initialize CAN bus communication here
        // Add your CAN bus communication logic
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Log.d("CanBusService", "Service started");
        // Start listening to the CAN bus
        startListeningToCanBus();
        return START_STICKY;
    }

    private void startListeningToCanBus() {
        // Implement CAN bus listening logic here
        // This method will run in the background
    }

    @Override
    public IBinder onBind(Intent intent) {
        // Return null because this service is not meant to be bound
        return null;
    }
}

CanBusApplication.java:

package com.example.j1939_android3;

import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.util.Log;

public class CanBusService extends Service {

    @Override
    public void onCreate() {
        super.onCreate();
        Log.d("CanBusService", "Service created");
        // Initialize CAN bus communication here
        // Add your CAN bus communication logic
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Log.d("CanBusService", "Service started");
        // Start listening to the CAN bus
        startListeningToCanBus();
        return START_STICKY;
    }

    private void startListeningToCanBus() {
        // Implement CAN bus listening logic here
        // This method will run in the background
    }

    @Override
    public IBinder onBind(Intent intent) {
        // Return null because this service is not meant to be bound
        return null;
    }
}

AndroidManifest:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">

    <uses-feature android:name="android.hardware.usb.host" />
    <uses-permission android:name="android.permission.USB_DEVICE" />

    <application
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.J1939_Android3"
        tools:targetApi="31">

        <activity android:name=".CanBusApplication"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <service
            android:name=".CanBusService"
            android:exported="false">
        </service>
    </application>

</manifest>