Extending from one or two classes in Android

 You can never actually extend two classes directly..some other methods available

MainActivity :

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;

public class MainActivity extends AppCompatActivity {

    private NetworkUtil util;

    @Override    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        util = new NetworkUtil(this);
        Log.e("any connectivity ?","Network connection is..."+isConnected());
    }

    public boolean isConnected()
    {
        return util.isConnected(this);
    }
}

NetworkUtil :

 

import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.telephony.TelephonyManager;

/** * @author emil http://stackoverflow.com/users/220710/emil */
public class NetworkUtil {


    public NetworkUtil(Context con) {

    }

    /**     * Get the network info     */    public static NetworkInfo getNetworkInfo(Context context){
        ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        return cm.getActiveNetworkInfo();
    }

    /**     * Check if there is any connectivity     */    public static boolean isConnected(Context context){
        NetworkInfo info = NetworkUtil.getNetworkInfo(context);
        return (info != null && info.isConnected());
    }

    /**     * Check if there is any connectivity to a Wifi network     */    public static boolean isConnectedWifi(Context context){
        NetworkInfo info = NetworkUtil.getNetworkInfo(context);
        return (info != null && info.isConnected() && info.getType() == ConnectivityManager.TYPE_WIFI);
    }

    /**     * Check if there is any connectivity to a mobile network     */    public static boolean isConnectedMobile(Context context){
        NetworkInfo info = NetworkUtil.getNetworkInfo(context);
        return (info != null && info.isConnected() && info.getType() == ConnectivityManager.TYPE_MOBILE);
    }

    /**     * Check if there is fast connectivity     */    public static boolean isConnectedFast(Context context){
        NetworkInfo info = NetworkUtil.getNetworkInfo(context);
        return (info != null && info.isConnected() && NetworkUtil.isConnectionFast(info.getType(),info.getSubtype()));
    }

    /**     * Check if the connection is fast     */    public static boolean isConnectionFast(int type, int subType){
        if(type==ConnectivityManager.TYPE_WIFI){
            return true;
        }else if(type==ConnectivityManager.TYPE_MOBILE){
            switch(subType){
                case TelephonyManager.NETWORK_TYPE_1xRTT:
                    return false; // ~ 50-100 kbps                case TelephonyManager.NETWORK_TYPE_CDMA:
                    return false; // ~ 14-64 kbps                case TelephonyManager.NETWORK_TYPE_EDGE:
                    return false; // ~ 50-100 kbps                case TelephonyManager.NETWORK_TYPE_EVDO_0:
                    return true; // ~ 400-1000 kbps                case TelephonyManager.NETWORK_TYPE_EVDO_A:
                    return true; // ~ 600-1400 kbps                case TelephonyManager.NETWORK_TYPE_GPRS:
                    return false; // ~ 100 kbps                case TelephonyManager.NETWORK_TYPE_HSDPA:
                    return true; // ~ 2-14 Mbps                case TelephonyManager.NETWORK_TYPE_HSPA:
                    return true; // ~ 700-1700 kbps                case TelephonyManager.NETWORK_TYPE_HSUPA:
                    return true; // ~ 1-23 Mbps                case TelephonyManager.NETWORK_TYPE_UMTS:
                    return true; // ~ 400-7000 kbps            /*             * Above API level 7, make sure to set android:targetSdkVersion             * to appropriate level to use these             */                case TelephonyManager.NETWORK_TYPE_EHRPD: // API level 11                    return true; // ~ 1-2 Mbps                case TelephonyManager.NETWORK_TYPE_EVDO_B: // API level 9                    return true; // ~ 5 Mbps                case TelephonyManager.NETWORK_TYPE_HSPAP: // API level 13                    return true; // ~ 10-20 Mbps                case TelephonyManager.NETWORK_TYPE_IDEN: // API level 8                    return false; // ~25 kbps                case TelephonyManager.NETWORK_TYPE_LTE: // API level 11                    return true; // ~ 10+ Mbps                // Unknown                case TelephonyManager.NETWORK_TYPE_UNKNOWN:
                default:
                    return false;
            }
        }else{
            return false;
        }
    }

}

Android splash screen using Runnable

import android.support.v7.app.AppCompatActivity;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;

public class MainActivity extends AppCompatActivity {

    private static String Tag;
    private Handler handler;
    private Runnable runnable;

    @Override    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initData();
    }
    public MainActivity() {
        this.runnable = null;
    }

    static {
        Tag = MainActivity.class.getName();
    }
    private void initData() {
        this.handler = new Handler();
        this.runnable = new MuRunnable();
    }
    private class MyRunnable implements Runnable {
        private ActivityRunnable() {
        }

        public void run() {
            MainActivity.this.startActivity(new Intent(MainActivity.this, SecondActivity.class));
            MainActivity.this.finish();
        }
    }

    @Override    protected void onResume() {
        super.onResume();
        this.handler.postDelayed(this.runnable, 2000);
    }

    @Override    protected void onPause() {
        super.onPause();
        this.handler.removeCallbacks(this.runnable);
    }
}