Detection of Internet Connection using android

1. MainXML File

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Detect Internet Status" />
   
    <Button android:id="@+id/btn_check"
        android:layout_height="wrap_content"
        android:layout_width="wrap_content"
        android:text="Check Internet Status"
        android:layout_centerInParent="true"/>

</RelativeLayout>

2. MainJava File

package com.example.internetconn;

import android.os.Bundle;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.view.Menu;
import android.view.View;
import android.widget.Button;

public class MainActivity extends Activity {

// flag for Internet connection status
    Boolean isInternetPresent = false;
   
    // Connection detector class
    ConnectionDetector cd;

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

        Button btnStatus = (Button) findViewById(R.id.btn_check);

        // creating connection detector class instance
        cd = new ConnectionDetector(getApplicationContext());

        /**
         * Check Internet status button click event
         * */
        btnStatus.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
               
                // get Internet status
                isInternetPresent = cd.isConnectingToInternet();

                // check for Internet status
                if (isInternetPresent) {
                    // Internet Connection is Present
                    // make HTTP requests
                    showAlertDialog(MainActivity.this, "Internet Connection",
                            "You have internet connection", true);
                } else {
                    // Internet connection is not present
                    // Ask user to connect to Internet
                    showAlertDialog(MainActivity.this, "No Internet Connection",
                            "You don't have internet connection.", false);
                }
            }

        });

    }

    /**
     * Function to display simple Alert Dialog
     * @param context - application context
     * @param title - alert dialog title
     * @param message - alert message
     * @param status - success/failure (used to set icon)
     * */
    public void showAlertDialog(Context context, String title, String message, Boolean status) {
        AlertDialog alertDialog = new AlertDialog.Builder(context).create();

        // Setting Dialog Title
        alertDialog.setTitle(title);

        // Setting Dialog Message
        alertDialog.setMessage(message);
       
        // Setting alert dialog icon
        alertDialog.setIcon((status) ? R.drawable.s : R.drawable.cross);

        // Setting OK Button
        alertDialog.setButton("OK", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {
            }
        });

        // Showing Alert Message
        alertDialog.show();
    }
}

3. ConnectionDetector.java

package com.example.internetconn;

import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
public class ConnectionDetector {



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

   public boolean isConnectingToInternet(){
       ConnectivityManager connectivity = (ConnectivityManager) _context.getSystemService(Context.CONNECTIVITY_SERVICE);
         if (connectivity != null)
         {
             NetworkInfo[] info = connectivity.getAllNetworkInfo();
             if (info != null)
                 for (int i = 0; i < info.length; i++)
                     if (info[i].getState() == NetworkInfo.State.CONNECTED)
                     {
                         return true;
                     }

         }
         return false;
   }
}


4. Add following permission in manifest file.

<uses-permission android:name="android.permission.INTERNET"/><uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>