Network Test on API 29 - Java

CheckNetwork.java

package com.example.simplenetwork;

import android.content.Context;
import android.net.ConnectivityManager;
import android.net.LinkProperties;
import android.net.Network;
import android.net.NetworkCapabilities;
import android.net.NetworkRequest;
import android.util.Log;

import androidx.annotation.NonNull;

public class CheckNetwork {

    private Context context;
    public CheckNetwork(Context context) {
        this.context = context;
    }

    
    void registerDefaultNetworkCallback(){
   try {
        ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);

       assert connectivityManager != null;
       connectivityManager.registerDefaultNetworkCallback(new ConnectivityManager.NetworkCallback(){
                @Override
                public void onAvailable(@NonNull android.net.Network network) {
                    super.onAvailable(network);
                    GlobalVars.isNetworkConnected = true;
                    Log.d("FLABS:", "onAvailable");
                }

                @Override
                public void onLost(@NonNull android.net.Network network) {
                    super.onLost(network);
                    GlobalVars.isNetworkConnected = false;
                    Log.d("FLABS:", "onLost");
                }

                @Override
                public void onBlockedStatusChanged(@NonNull Network network, boolean blocked) {
                    super.onBlockedStatusChanged(network, blocked);
                                        Log.d("FLABS:", "onBlockedStatusChanged");

                }

                @Override
                public void onCapabilitiesChanged(@NonNull Network network, @NonNull NetworkCapabilities networkCapabilities) {
                    super.onCapabilitiesChanged(network, networkCapabilities);
                                        Log.d("FLABS:", "onCapabilitiesChanged");
                }

                @Override
                public void onLinkPropertiesChanged(@NonNull Network network, @NonNull LinkProperties linkProperties) {
                    super.onLinkPropertiesChanged(network, linkProperties);
                    Log.d("FLABS:", "onLinkPropertiesChanged");
                }

                @Override
                public void onLosing(@NonNull Network network, int maxMsToLive) {
                    super.onLosing(network, maxMsToLive);
                    Log.d("FLABS:", "onLosing");
                }

                @Override
                public void onUnavailable() {
                    super.onUnavailable();
                    Log.d("FLABS:", "onUnavailable");
                }
            });
                } catch (Exception e) {
            Log.d("FLABS: Exception in registerDefaultNetworkCallback", "hello");
            GlobalVars.isNetworkConnected = false;
        }
    }
    
    
    
    void registerNetworkCallback(){
        try {
            ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
            NetworkRequest.Builder builder = new NetworkRequest.Builder();

            assert connectivityManager != null;
            connectivityManager.registerNetworkCallback(builder.build(), new ConnectivityManager.NetworkCallback(){
                @Override
                public void onAvailable(@NonNull android.net.Network network) {
                    super.onAvailable(network);
                    GlobalVars.isNetworkConnected = true;
                    Log.d("FLABS:", "onAvailable");
                }

                @Override
                public void onLost(@NonNull android.net.Network network) {
                    super.onLost(network);
                    GlobalVars.isNetworkConnected = false;
                    Log.d("FLABS:", "onLost");
                }

                @Override
                public void onBlockedStatusChanged(@NonNull Network network, boolean blocked) {
                    super.onBlockedStatusChanged(network, blocked);
                                        Log.d("FLABS:", "onBlockedStatusChanged");

                }

                @Override
                public void onCapabilitiesChanged(@NonNull Network network, @NonNull NetworkCapabilities networkCapabilities) {
                    super.onCapabilitiesChanged(network, networkCapabilities);
                                        Log.d("FLABS:", "onCapabilitiesChanged");
                }

                @Override
                public void onLinkPropertiesChanged(@NonNull Network network, @NonNull LinkProperties linkProperties) {
                    super.onLinkPropertiesChanged(network, linkProperties);
                    Log.d("FLABS:", "onLinkPropertiesChanged");
                }

                @Override
                public void onLosing(@NonNull Network network, int maxMsToLive) {
                    super.onLosing(network, maxMsToLive);
                    Log.d("FLABS:", "onLosing");
                }

                @Override
                public void onUnavailable() {
                    super.onUnavailable();
                    Log.d("FLABS:", "onUnavailable");
                }
            });

        } catch (Exception e) {
            Log.d("FLABS: Exception in registerNetworkCallback", "hello");
            GlobalVars.isNetworkConnected = false;
        }
    }
}

GlobalVars.java

package com.example.simplenetwork;

public class GlobalVars {
          public static int counter = 0;
          public static boolean isNetworkConnected = false;
}

MainActivity.java

package com.example.simplenetwork;

import android.annotation.SuppressLint;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;

import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;

import com.google.android.material.floatingactionbutton.FloatingActionButton;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);


        // Register NetworkCallback -- need to call this when activity starts
        CheckNetwork network = new CheckNetwork(getApplicationContext());
        
        /*
         * registerNetworkCallback() is available from API-21 and above
         * But it will show status of all available network. Hence you would
         * to query onCapabilitiesChanged() to make sure your intended network is active or not.
         */
        // network.registerNetworkCallback();
        
        
        /*
         * network.registerDefaultNetworkCallback() is available from API-24
         * Unlike its counterpart, it will only register status of current active network
         * Hence no need to check with onCapabilitiesChanged(). But downside is that it 
         * is available since API-24 while current recommendation (in 2019) is to maintain 
         * minimum support for API-23 Marshmallo.
         */
        network.registerDefaultNetworkCallback(); 
        final TextView text = findViewById(R.id.test_message);

        FloatingActionButton fab = findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @SuppressLint({"SetTextI18n", "DefaultLocale"})
            @Override
            public void onClick(View view) {

                GlobalVars.counter++;
                if (GlobalVars.isNetworkConnected) {
                    text.setText(String.format("Counter is %d, And network is Connected", GlobalVars.counter));
                } else {
                    text.setText(String.format("Counter is %d, And network is Not Connected", GlobalVars.counter));

                }
            }
        });
    }
}