Android service to check internet connectivity?

Question

I want to create an Android service, which notifies the main activity whenever disconnects and when internet reconnects again. I have following function for checking interne

Answer 1

This is a Kotlin version, following Francesco Laurita's solution:

private val broadcastReceiver by lazy {
    NetworkListener.create({
        btnOnlineVideos.visibility = View.VISIBLE
    }, {
        btnOnlineVideos.visibility = View.GONE
    })
}

override fun onResume() {
    super.onResume()

    NetworkListener.register(this, broadcastReceiver)
}

override fun onPause() {
    super.onPause()

    NetworkListener.unregister(this, broadcastReceiver)
}

For this to work I simply override the onResume and onPause methods, to register and unregister the BroadcastReceiver.

How does this work?

I created the following class that helps to initialize, register and unregister the BroadcastReceiver. That way there is no need to repeate most of the boilerplate code.

package com.programacionymas.app.services

import android.content.BroadcastReceiver
import android.content.Context
import android.content.Intent
import android.content.IntentFilter
import android.net.ConnectivityManager
import android.net.NetworkInfo
import android.os.Parcelable
import android.util.Log

object NetworkListener {

    fun create(onNetworkUp: () -> Unit, onNetworkDown: () -> Unit): BroadcastReceiver {
        return object : BroadcastReceiver() {
            override fun onReceive(context: Context, intent: Intent) {

                intent.extras?.getParcelable("networkInfo")?.let {
                    val info = it as NetworkInfo
                    val state: NetworkInfo.State = info.state

                    Log.d("BroadcastReceiver", "$info $state")
                    if (state === NetworkInfo.State.CONNECTED) {
                        onNetworkUp()
                    } else {
                        onNetworkDown()
                    }
                }

            }
        }
    }

    fun register(context: Context, broadcastReceiver: BroadcastReceiver) {
        val intentFilter = IntentFilter()
        intentFilter.addAction(ConnectivityManager.CONNECTIVITY_ACTION)
        context.registerReceiver(broadcastReceiver, intentFilter)
    }

    fun unregister(context: Context, broadcastReceiver: BroadcastReceiver) {
        context.unregisterReceiver(broadcastReceiver)
    }

}

---

In case you need to execute sentences only for one of the states, you can pass a null anonymous function too:

private val broadcastReceiver by lazy {
    NetworkListener.create(null, {
        toast(getString(R.string.check_your_internet))
        finish()
    })
}

And declare the parameters as optionals in the create method:

fun create(onNetworkUp: (()->Unit)?, onNetworkDown: (()->Unit)?): BroadcastReceiver {/* ... */}

As well as invoking the functions only if they were sent as arguments:

if (state === NetworkInfo.State.CONNECTED) {
    onNetworkUp?.invoke()
} else {
    onNetworkDown?.invoke()
}