Olá eu sou iniciante no anroid. Criei gavetas e fragmentos de navegação. Eu posso obter dados de json com url. Está funcionando enquanto está online. Mas telefone quando estiver offline, estou recebendo o erro "incapaz de resolver o host". Quero obter dados do URL com o json enquanto estiver offline. Não está em cacheinsira a descrição da imagem aqui

fragmento

private static final String jsonUrl = "http://sunumsitesi.com/json.php";
private ProgressDialog pDialog;
private List<Urun> urunList = new ArrayList<Urun>();
private ListView listView;
private CustomListAdapter adapter;
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
    View root = inflater.inflate(R.layout.fragment_yemek, container, false);
    return root;
}
@Override
public void onActivityCreated(Bundle savedInstanceState)
{
    super.onActivityCreated(savedInstanceState);
    View v = getView();
    if(v!=null)
    {
        listView = (ListView) v.findViewById(R.id.yemekList);
        adapter = new CustomListAdapter(getActivity(), urunList);
        listView.setAdapter(adapter);

        pDialog = new ProgressDialog(getActivity());
        pDialog.setMessage("Loading...");
        pDialog.show();
        JsonArrayRequest urunReq = new JsonArrayRequest(jsonUrl, new Response.Listener<JSONArray>()
        {
            @Override
            public void onResponse(JSONArray response)
            {
                hidePDialog();
                for (int i = 0; i < response.length(); i++)
                {
                    try
                    {

                        JSONObject obj = response.getJSONObject(i);
                        Urun urun = new Urun();
                        urun.setUrun_adi(obj.getString("urun_adi"));
                        urun.setUrl("http://www.iremdeveci.com/ornekler/resimler/resim.png");//example
                        urunList.add(urun);
                    } catch (JSONException ex)
                    {
                        ex.printStackTrace();
                    }
                }
                adapter.notifyDataSetChanged();
            }
        }, new Response.ErrorListener()
        {
            @Override
            public void onErrorResponse(VolleyError volleyError)
            {
                Toast.makeText(getActivity(), volleyError.getMessage(), Toast.LENGTH_LONG).show();
            }
        });
        AppController.getmInstance().addToRequestQueue(urunReq);
    }
}

@Override
public void onDestroy()
{
    super.onDestroy();
    hidePDialog();
}
private void hidePDialog()
{
    if(pDialog!=null)
    {
        pDialog.dismiss();
        pDialog=null;
    }
}

e CustomListAdapter (estenda BaseAdapter)

private Activity activity;
private LayoutInflater inflater;
private List<Urun> urunItems;
ImageLoader imageLoader = AppController.getmInstance().getmImageLoader();
public CustomListAdapter(Activity activity,List<Urun> urunItems)
{
    this.activity=activity;
    this.urunItems=urunItems;
}

@Override
public int getCount()
{
    return urunItems.size();
}

@Override
public Object getItem(int location)
{
    return urunItems.get(location);
}

@Override
public long getItemId(int position)
{
    return position;
}

@Override
public View getView(int position, View convertView, ViewGroup parent)
{
    if (inflater==null)
    {
        inflater=(LayoutInflater)activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    }
    if (convertView==null)
    {
        convertView=inflater.inflate(R.layout.list_row,null);
    }
    if (imageLoader==null)
    {
        imageLoader=AppController.getmInstance().getmImageLoader();
    }
    NetworkImageView urunResim=(NetworkImageView)convertView.findViewById(R.id.urunResim);
    TextView urun_adi= (TextView)convertView.findViewById(R.id.urun_adi);
    Urun u = urunItems.get(position);

    urunResim.setImageUrl(u.getUrl(),imageLoader);
    urun_adi.setText(u.getUrun_adi());
    return convertView;
}

LruBitmapCache.java

public static int getDefaultLruCacheSize()
{
    final int maxMemory=(int)(Runtime.getRuntime().maxMemory()/1024);
    final int cacheSize= maxMemory/8;
    return cacheSize;
}
public LruBitmapCache()
{
    this(getDefaultLruCacheSize());
}
public LruBitmapCache(int sizeInKiloBytes)
{
    super(sizeInKiloBytes);
}

@Override
protected int sizeOf(String key, Bitmap value)
{
    return value.getRowBytes() * value.getHeight()/1024;
}

@Override
public Bitmap getBitmap(String url)
{
    return get(url);
}

@Override
public void putBitmap(String url, Bitmap bitmap)
{
    put(url,bitmap);
}