Lazy Load listview Item from server json response

Question

Я разрабатываю приложение для Android, которое загружает данные с сервера с помощью json-парсера. Я хочу загрузить данные из 10 элементов с сервера и когда пользователь прокручивает вниз список list 10 загружать часть детали с сервера и добавлять в текущее listview (например, рыночные приложения).

здесь код Java:

public class AllProductsActivity extends ListActivity { 
    //jpcode 
    int part=0; 
    String refreshNumber="0"; 
    //convert to shamsi 
    Roozh jCal = new Roozh(); 

    String myjpdiff; 
    ImageButton btnNewProduct; 
    View ntCheck; 
    private SessionManager session; 
    private Button logout; 
    //internet check jp 
    // flag for Internet connection status 
     Boolean isInternetPresent = false; 

     // Connection detector class 
     ConnectionDetector cd; 

     //end internet check jp 
     private SQLiteHandler db; //jpcode 
    //end jpcode 

    // Progress Dialog 
    private ProgressDialog pDialog; 

    // Creating JSON Parser object 
    JSONParser jParser = new JSONParser(); 

    ArrayList<HashMap<String, String>> productsList; 

    // url to get all products list 
    private static String url_all_products = "http://www.jpdesign.ir/android_login_api/ac/get_all_products.php"; 

    // JSON Node names 
    private static final String TAG_SUCCESS = "success"; 
    private static final String TAG_PRODUCTS = "products"; 
    private static final String TAG_PID = "pid"; 
    private static final String TAG_NAME = "name"; 
    //jpcode 
    private static final String TAG_AUTH = "auth"; 
    private static final String TAG_HIT = "hit"; 
    private static final String TAG_DATE = "created_at"; 
    private static final String TAG_JPTIME = "jptime"; 
    private static final String TAG_JPPart = "part"; 
    private TextView txtName; 
    // products JSONArray 
    JSONArray products = null; 
    Typeface jpfont; 

    public PullToRefreshListView listView; 
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     overridePendingTransition(R.anim.push_right_in,R.anim.push_right_out); 
     setContentView(R.layout.all_products); 


      jpfont = Typeface.createFromAsset(getAssets(), "fonts/yekan.ttf"); 
      TextView fakeDate= (TextView) findViewById(R.id.textView1); 
      fakeDate.setTypeface(jpfont); 


     // SQLite database handler 
     db = new SQLiteHandler(getApplicationContext()); 
     // session manager 
     session = new SessionManager(getApplicationContext()); //jpcode 

     //adding slidemenu 
     final SlidingMenu menu = new SlidingMenu(this); 
     menu.setMode(SlidingMenu.RIGHT); 
     menu.setTouchModeAbove(SlidingMenu.TOUCHMODE_FULLSCREEN); 
     menu.setShadowWidthRes(R.dimen.shadow_width); 
     menu.setShadowDrawable(R.drawable.shadowright); 
     menu.setBehindOffsetRes(R.dimen.slidingmenu_offset); 
     menu.setFadeDegree(0.35f); 
     menu.attachToActivity(this, SlidingMenu.SLIDING_CONTENT); 
     menu.setMenu(R.layout.slide_layout); 
     ImageButton iconfehrest = (ImageButton) findViewById(R.id.sliding); 
// get name of user 
     // Fetching user details from sqlite 
     HashMap<String, String> user = db.getUserDetails(); 

     String name = user.get("name"); 
     String email = user.get("email"); 
     txtName = (TextView) findViewById(R.id.mnt); 
     // Displaying the user details on the screen 
     Log.d("LOG", name +" and "+email); 
     txtName.setText(name); 
     //txtEmail.setText(email); 


///end get name 
     iconfehrest.setOnClickListener(new View.OnClickListener() { 

      @Override 
      public void onClick(View view) { 
       menu.toggle(); 
      } 
     }); 


     //end slide menu 



//jpcode 
     logout= (Button) findViewById(R.id.Ulogout); 
     logout.setOnClickListener(new View.OnClickListener() { 

      @Override 
      public void onClick(View v) { 
       logoutUser(); 
      } 
     }); 
     final View ntCheck = findViewById(R.id.net_check); 
     ntCheck.setVisibility(View.GONE); 
     // creating connection detector class instance 
     cd = new ConnectionDetector(getApplicationContext()); 

     // get Internet status 
     isInternetPresent = cd.isConnectingToInternet(); 
     ImageButton ntchecker= (ImageButton) findViewById(R.id.nt_check); 

     ntchecker.setOnClickListener(new OnClickListener() { 

     @Override 
     public void onClick(View arg0) { 
      // TODO Auto-generated method stub 
      Intent i = new Intent(AllProductsActivity.this,AllProductsActivity.class);  
      startActivity(i); 
      } 

    }); 

    //jp pull to refresh 
     StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder() .detectAll().penaltyLog().build(); 
     StrictMode.setThreadPolicy(policy); 
      listView = (PullToRefreshListView) getListView(); 
      listView.setOnRefreshListener(new OnRefreshListener() { 
       //@Override 
       public void onRefresh() { 
        // Do work to refresh the list here. 
        productsList = new ArrayList<HashMap<String, String>>(); 

        // Loading products in Background Thread 
        new LoadAllProducts().execute(); 
        pDialog.hide(); 

       } 
      }); 


      // end of jp pull to refresh 


     // check for Internet status 
     if (isInternetPresent) { 
      // Internet Connection is Present 
      // make HTTP requests 
      // Hashmap for ListView 
      productsList = new ArrayList<HashMap<String, String>>(); 
      ntCheck.setVisibility(View.GONE); //hide internet checker 
      // Loading products in Background Thread 
      new LoadAllProducts().execute(); 
     } else { 
      // Internet connection is not present 
      // Ask user to connect to Internet 
      Log.d("No Internet Connection", "You don't have internet connection."); 
      //Toast.makeText(this, "You don't have internet connection.", Toast.LENGTH_LONG).show(); 
      ntCheck.setVisibility(View.VISIBLE); 
     } 

     btnNewProduct = (ImageButton) findViewById(R.id.newpost); 
     ImageButton searchBtn = (ImageButton) findViewById(R.id.SearchBtn); 

     btnNewProduct.setOnClickListener(new View.OnClickListener() { 

      @Override 
      public void onClick(View view) { 
       // Launching create new product activity 
       Intent i = new Intent(AllProductsActivity.this, NewProductActivity.class); 
       startActivity(i); 

      } 
     }); 
     //end of jp 
     // Hashmap for ListView 
     //jpdast productsList = new ArrayList<HashMap<String, String>>(); 

     // Loading products in Background Thread 
     //jpdast new LoadAllProducts().execute(); 

     // Get listview 
     ListView lv = getListView(); 



     // on seleting single product 
     // launching Edit Product Screen 
     lv.setOnItemClickListener(new OnItemClickListener() { 

      @Override 
      public void onItemClick(AdapterView<?> parent, View view, 
        int position, long id) { 
       // getting values from selected ListItem 
       String pid = ((TextView) view.findViewById(R.id.pid)).getText() 
         .toString(); 

       // Starting new intent 
       Intent in = new Intent(getApplicationContext(), 
         ViewPro.class); 
       // sending pid to next activity 
       in.putExtra(TAG_PID, pid); 

       // starting new activity and expecting some response back 
       startActivityForResult(in, 100); 
      } 
     }); 


     //jp scroller 

       //add the footer before adding the adapter, else the footer will not load! 
//    View footerView = ((LayoutInflater)this.getSystemService(Context.LAYOUT_INFLATER_SERVICE)).inflate(R.layout.footer, null, false); 
//    this.getListView().addFooterView(footerView); 
       //Here is where the magic happens 
       lv.setOnScrollListener(new OnScrollListener() { 
        ListAdapter adapter = new SimpleAdapter(
          AllProductsActivity.this, productsList, 
          R.layout.list_item, new String[] { TAG_PID, 
            TAG_NAME,TAG_AUTH,TAG_HIT, TAG_DATE}, 
          new int[] { R.id.pid, R.id.name, R.id.auth, R.id.hit, R.id.date } 

          ); 
        @Override 
        public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) { 
           int lastItem = firstVisibleItem + visibleItemCount; 
           int lastItemPosition=adapter.getCount(); 
         if (adapter.getCount() >= 10 && lastItem > adapter.getCount() - 6) { 
          boolean isLoading = false; 
          if (!isLoading) { 
           if(isInternetPresent){ 
            if(lastItem > lastItemPosition){ 
             //productsList = new ArrayList<HashMap<String, String>>(); 

             // Loading products in Background Thread 
             new LoadAllProducts().execute(); 
             //receivedData(); 
             Log.d("LOG", "jpdesign is here"); 
             ((BaseAdapter) adapter).notifyDataSetChanged(); 
             part += 1; 
             } 
            } 
          isLoading = true; 
           } 
          } 
         } 
          public void onScrollStateChanged(AbsListView view, int scrollState) {} 

        }); 

       //jp end scroller 


    } 

    // Response from Edit Product Activity 
    @Override 
    protected void onActivityResult(int requestCode, int resultCode, Intent data) { 
     super.onActivityResult(requestCode, resultCode, data); 
     // if result code 100 
     if (resultCode == 100) { 
      // if result code 100 is received 
      // means user edited/deleted product 
      // reload this screen again 
      Intent intent = getIntent(); 
      finish(); 
      startActivity(intent); 
     } 

    } 

    /** 
    * Background Async Task to Load all product by making HTTP Request 
    * */ 
    class LoadAllProducts extends AsyncTask<String, String, String> { 

     /** 
     * Before starting background thread Show Progress Dialog 
     * */ 
     @Override 
     protected void onPreExecute() { 
      super.onPreExecute(); 
      pDialog = new ProgressDialog(AllProductsActivity.this); 
      pDialog.setMessage("در حال دریافت اطلاعات ..."); 
      pDialog.setIndeterminate(false); 
      pDialog.setCancelable(false); 
      pDialog.show(); 

     } 

     /** 
     * getting All products from url 
     * */ 
     protected String doInBackground(String... args) { 


      Log.d("LOG", part+""); 
      List<NameValuePair> params2 = new ArrayList<NameValuePair>(); 
      params2.add(new BasicNameValuePair(TAG_JPPart, "" + part)); 

      JSONObject json2 = jParser.makeHttpRequest(url_all_products, "POST", params2); 

      Log.d("post checker: ", json2.toString()); 

      // Building Parameters 
      List<NameValuePair> params = new ArrayList<NameValuePair>(); 
      // getting JSON string from URL 
      JSONObject json = jParser.makeHttpRequest(url_all_products, "GET", params); 


      // Check your log cat for JSON reponse 
      //Log.d("jpdesign All Products: ", json.toString()); 

      try { 
       // Checking for SUCCESS TAG 
       int success = json.getInt(TAG_SUCCESS); 

       if (success == 1) { 
        //adapter.notifyDataSetChanged(); 

        refreshNumber="1"; 
        // products found 
        // Getting Array of Products 
        products = json2.getJSONArray(TAG_PRODUCTS); 
        String myjpdate=json.getString(TAG_JPTIME); 
        // Log.d("TIME TEST", myjpdate); 
         Log.d("TIME TEST", products+""); 
        // looping through All Products 
       //for (int i = 0; i < products.length(); i++) { 
         for (int i = 0; i < products.length(); i++) {  
         JSONObject c = products.getJSONObject(i); 

         // Storing each json item in variable 
         String id = c.getString(TAG_PID); 
         String name = c.getString(TAG_NAME); 
         //jpcode 
         String auth = c.getString(TAG_AUTH); 
         String hit = c.getString(TAG_HIT); 
         String date = c.getString(TAG_DATE); 

         //jptime diff 
         String dateStart = date; 
         String dateStop = myjpdate; 

          Date d1 = null; 
          Date d2 = null; 
          Date jd1 = null; 
          Date jd2 = null; 

          Date fyear = null; 


          SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); 
          SimpleDateFormat jpformat = new SimpleDateFormat("yyyy-MM-dd"); 






          try { 
           d1 = format.parse(dateStart); 
           d2 = format.parse(dateStop); 
           jd1 =jpformat.parse(dateStart); 
           jd2 =jpformat.parse(dateStop); 

           DateFormat formatter ; 

           formatter = new SimpleDateFormat("yyyy-MM-dd"); 
           fyear = (Date)formatter.parse(dateStart); 


           // (3) create a new String using the date format we want 
           String YMD = formatter.format(fyear); 

           int len=YMD.length(); 
           String[] myInArray=new String[len]; 

            String FY=String.valueOf(YMD.charAt(0))+String.valueOf(YMD.charAt(1))+String.valueOf(YMD.charAt(2))+String.valueOf(YMD.charAt(3)); 
            String FM=String.valueOf(YMD.charAt(5))+String.valueOf(YMD.charAt(6)); 
            String FD=String.valueOf(YMD.charAt(8))+String.valueOf(YMD.charAt(9)); 

           jCal.GregorianToPersian(Integer.parseInt(FY), Integer.parseInt(FM), Integer.parseInt(FD)); 
           String myconverttime= jCal.toString(); 
           //in milliseconds 
           long diff = d2.getTime() - d1.getTime(); 
           long jpdiff = jd2.getTime() - jd1.getTime(); 


           long diffSeconds = diff/1000 % 60; 
           long diffMinutes = diff/(60 * 1000) % 60; 
           long diffHours = diff/(60 * 60 * 1000) % 24; 
           long diffDays = diff/(24 * 60 * 60 * 1000); 
// 1s=1000 ,1m=60000,1h=3.6e+6 1day = 86400000 


          if(jpdiff==0 && diff<=60000){ myjpdiff="هم اکنون";} 
          if(jpdiff==0 && diff>60000 && diff<(59*60000)){ myjpdiff=diffMinutes+" دقیقه قبل";} 
          if(jpdiff==0 && diff>(60*60000) && diff<(24*59*60000)){ myjpdiff=diffHours+" ساعت قبل";} 
          if(jpdiff==86400000){ myjpdiff=" 1 روز قبل ";} 
          if(jpdiff>86400000){ myjpdiff=myconverttime;} 


          Log.d("TIME TEST",FY+" "+diff+" "+ jpdiff+" "+diffDays+"day "+diffHours+"hour "+diffMinutes+""); 
         } catch (Exception e) { 
          e.printStackTrace(); 
         } 


         //end jptime diff 
         // creating new HashMap 
         HashMap<String, String> map = new HashMap<String, String>(); 

         // adding each child node to HashMap key => value 
         map.put(TAG_PID, id); 
         map.put(TAG_NAME, name); 
         map.put(TAG_AUTH, auth); //jpcode 
         map.put(TAG_HIT, hit); //jpcode 
         map.put(TAG_DATE, myjpdiff); //jpcode 
         // adding HashList to ArrayList 
         productsList.add(map); 


        } 



       } else { 
        refreshNumber="0"; 
        // no products found 
        // Launch Add New product Activity 
        Intent i = new Intent(getApplicationContext(), 
          NewProductActivity.class); 
        // Closing all previous activities 
        i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP); 
        startActivity(i); 
       } 

      } catch (JSONException e) { 
       e.printStackTrace(); 
      } 

      return null; 

     } 

     /** 
     * After completing background task Dismiss the progress dialog 
     * **/ 
     protected void onPostExecute(String file_url) { 

      // dismiss the dialog after getting all products 
      pDialog.dismiss(); 

      // updating UI from Background Thread 
      runOnUiThread(new Runnable() { 
       public void run() { 
        /** 
        * Updating parsed JSON data into ListView 
        **/ 

//     TextView dt=(TextView) findViewById(R.id.date); 
//     dt.setTypeface(jpfont); 
        ListAdapter adapter = new SimpleAdapter(
          AllProductsActivity.this, productsList, 
          R.layout.list_item, new String[] { TAG_PID, 
            TAG_NAME,TAG_AUTH,TAG_HIT, TAG_DATE}, 
          new int[] { R.id.pid, R.id.name, R.id.auth, R.id.hit, R.id.date } 

          ); 


        // updating listview 
        setListAdapter(adapter); 


        ((PullToRefreshListView) getListView()).onRefreshComplete(); 

       } 

      }); 

     } 





    } 


    //jpcode logout 

    private void logoutUser() { 
     session.setLogin(false); 

     db.deleteUsers(); 

     // Launching the login activity 
     Intent intent = new Intent(AllProductsActivity.this, LoginActivity.class); 
     startActivity(intent); 
     finish(); 
    } 
    //end jp logout 
} 

и вот файл PHP на сервере:

<?php 

header("Cache-Control: no-cache, must-revalidate"); // HTTP/1.1 

header("Expires: Sat, 26 Jul 2014 05:00:00 GMT"); // Date in the past 

?> 
<?php 

/* 
* Following code will list all the products 
*/ 

// array for JSON response 
$response = array(); 


// include db connect class 
require_once __DIR__ . '/db_connect.php'; 

// connecting to db 
$db = new DB_CONNECT(); 

// get all products from products table 

//jpadd codes 
$part = $_POST['part']; 
//$part = $_GET['part']; 
    $start = $part * 10; 

$result = mysql_query("SELECT *FROM products ORDER BY`created_at` DESC LIMIT $start, 10") or die(mysql_error()); 
//$result = mysql_query("SELECT *FROM products ORDER BY`created_at` DESC") or die(mysql_error()); 

// check for empty result 
if (mysql_num_rows($result) > 0) { 
    // looping through all results 
    // products node 
$response["jptime"] = date("Y-m-d H:i:s"); 
//$jptime["my_date"]= date("Y-m-d H:i:s"); 
    $response["products"] = array(); 
$response["part"] = $part; 

    while ($row = mysql_fetch_array($result)) { 
     // temp user array 
     $product = array(); 
     $product["pid"] = $row["pid"]; 
     $product["name"] = $row["name"]; 
     //$product["price"] = $row["price"]; 
     //$product["description"] = $row["description"]; 
     $product["created_at"] = $row["created_at"]; 
     //$product["updated_at"] = $row["updated_at"]; 
     //jpcode 
     $product["auth"] = $row["auth"]; 
     $product["hit"] = $row["hit"]; 

    // $my_date = date("Y-m-d H:i:s"); 


     // push single product into final response array 
     array_push($response["products"], $product); 
    } 
    // success 
    $response["success"] = 1; 

    // echoing JSON response 
    echo json_encode($response); 
} else { 
    // no products found 
    $response["success"] = 0; 
    $response["message"] = "محصولی یافت نشد"; 

    // echo no users JSON 
    echo json_encode($response); 
} 
?> 

, но когда пользователь прокрутки вниз списка ничего не произойдет

Answer 1

My application code which worked: 


public class Product_Listing extends Fragment 
{ 
private static final String TAG = SubCategoryActivity.class.getSimpleName(); 
private static final String TAG_IMAGEPATH = "imagepath"; 
private static final String TAG_PRODUCTID = "productid"; 
private static final String TAG_PRODUCTNAME = "productname"; 
private static final String TAG_SUPPLIERID = "supplierid"; 
private static final String TAG_SUPPLIERNAME = "suppliername"; 
private static final String TAG_CATEGORY_ID = "catid"; 
private static final String TAG_PRODUCT_COUNT = "productcount"; 

private ProgressDialog pDialog; 
private List<Products> catList = new ArrayList<Products>(); 
private ListView listView; 
private ProductsAdapter adapter; 
int id_count = 0; 

private int current_page = 0; 
int mPreLast; 

public Product_Listing() { 
} 

@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, 
         Bundle savedInstanceState) { 
    return inflater.inflate(R.layout.fragment_product__listing, container, false); 
} 

@Override 
public void onActivityCreated(@Nullable Bundle savedInstanceState) { 
    super.onActivityCreated(savedInstanceState); 
    listView = (ListView) getView().findViewById(R.id.list1); 
    adapter = new ProductsAdapter(getActivity(), catList); 
    listView.setAdapter(adapter); 
    int currentPosition = listView.getFirstVisiblePosition(); 
    listView.setSelectionFromTop(currentPosition + 1, 0); 

    listView.setOnScrollListener(new AbsListView.OnScrollListener() 
    { 
     @Override 
     public void onScrollStateChanged(AbsListView absListView, int i) 
     { 

     } 

     @Override 
     public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) 
     { 
      int lastItem = firstVisibleItem + visibleItemCount; 
      if(lastItem == totalItemCount){ 
       if (mPreLast != lastItem) 
       { 
        mPreLast = lastItem; 
        new LoadProductDesc().execute(); 
       } 
      } 
     } 
    }); 

    new LoadProductDesc().execute(); 
} 



private void hidePDialog() { 
    if (pDialog != null && pDialog.isShowing()) { 
     pDialog.dismiss(); 
     pDialog = null; 
    } 
} 

class LoadProductDesc extends AsyncTask<String, String, String> { 

    /** 
    * Before starting background thread Show Progress Dialog 
    */ 
    @Override 
    protected void onPreExecute() { 
     super.onPreExecute(); 
     pDialog = new ProgressDialog(getActivity()); 
     pDialog.setMessage("Getting Data ..."); 
     pDialog.setIndeterminate(false); 
     pDialog.setCancelable(true); 
     pDialog.show(); 
    } 


    protected String doInBackground(String... args) { 

     HttpClient httpclient = new DefaultHttpClient(); 
     HttpResponse response; 
     String responseString = null; 
     try { 
      // make a HTTP request 

      response = httpclient.execute(new HttpGet()); 
      StatusLine statusLine = response.getStatusLine(); 
      if (statusLine.getStatusCode() == HttpStatus.SC_OK) { 
       ByteArrayOutputStream out = new ByteArrayOutputStream(); 
       response.getEntity().writeTo(out); 
       out.close(); 
       responseString = out.toString(); 
      } else { 
       // close connection 
       response.getEntity().getContent().close(); 
       throw new IOException(statusLine.getReasonPhrase()); 
      } 
     } catch (Exception e) { 
      Log.d("Test", "Couldn't make a successful request!"); 
     } 
     return responseString; 
    } 


    protected void onPostExecute(final String response) { 

     super.onPostExecute(response); 
     // Creating volley request obj 
     String s1 = getActivity().getIntent().getStringExtra("index"); 
     current_page += 1; 
     final String url = "Your URL Link" + s1 + "," + current_page; 

       JsonArrayRequest movieReq = new JsonArrayRequest(url, 
         new Response.Listener<JSONArray>() { 
          @Override 
          public void onResponse(JSONArray response) { 
           Log.d(TAG, response.toString()); 

           try 
           { 
            if (isNetworkStatusAvialable (getActivity())) { 

              // Parsing json 
              for (int i = 0; i < response.length() && response.length() != 0; i++) 
              { 
               JSONObject obj = response.getJSONObject(i); 
               Products products = new Products(); 
               id_count = id_count + 1; 
               products.setProductName(obj.getString(TAG_PRODUCTNAME)); 
               products.setThumbnailUrl(obj.getString(TAG_IMAGEPATH)); 
               products.setProductID(obj.getInt(TAG_PRODUCTID)); 
               products.setSupplierName(obj.getString(TAG_SUPPLIERNAME)); 
               products.setSupplierID(obj.getInt(TAG_SUPPLIERID)); 
               products.setCategoryID(obj.getInt(TAG_CATEGORY_ID)); 
               String count = obj.getString(TAG_PRODUCT_COUNT); 

               catList.add(products); 

               TextView textView = (TextView) getView().findViewById(R.id.ListofProducts); 
               textView.setText(String.valueOf("Total 1 to " + id_count + " Products listed of " + count)); 
              } 

            } 
            else 
            { 
             Toast.makeText(getActivity(),"Check Internet Connectivity!!",Toast.LENGTH_LONG).show(); 
             return; 
            } 

           } catch (JSONException e) { 
            e.printStackTrace(); 
           } catch (NullPointerException ne) { 
            Toast.makeText(getActivity(), "Check Internet Connectivity!!", Toast.LENGTH_LONG).show(); 
           } 
           hidePDialog(); 

           // notifying list adapter about data changes 
           // so that it renders the list view with updated data 
           adapter.notifyDataSetChanged(); 

          } 
         }, new Response.ErrorListener() { 
        @Override 
        public void onErrorResponse(VolleyError error) { 
         VolleyLog.d(TAG, "Error: " + error.getMessage()); 
         hidePDialog(); 
        } 
       }); 
       // Adding request to request queue 
       AppController.getInstance().addToRequestQueue(movieReq); 
      } 



} 

public static boolean isNetworkStatusAvialable (Context context) { 
    ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE); 
    if (connectivityManager != null) 
    { 
     NetworkInfo netInfos = connectivityManager.getActiveNetworkInfo(); 
     if(netInfos != null) 
      if(netInfos.isConnected()) 
       return true; 
    } 
    return false; 
} 


    }