Volley class

BitmapLruCache

public class BitmapLruCache extends LruCache<String, Bitmap> implements ImageCache {
    public BitmapLruCache(int maxSize) {
        super(maxSize);
    }

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

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

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

customadapter

public class CustomAdapter extends ArrayAdapter<Offer> {
	// View lookup cache
	
	public CustomAdapter(Context context,
						int textViewResourceId, 
						ArrayList<Offer> offers
						){
		super(context,textViewResourceId,offers);
	}
	
    private class ViewHolder {
        TextView briefOfferTextView;
        TextView extendedOfferTextView;
        NetworkImageView offerImageView;
        
        public ViewHolder(View v) {
        	briefOfferTextView = (TextView) v.findViewById(R.id.briefOfferTextView);
        	extendedOfferTextView = (TextView) v.findViewById(R.id.extendedOfferTextView);
            offerImageView = (NetworkImageView) v.findViewById(R.id.offerImageView);
        	
            v.setTag(this);
        }
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View v = convertView;

        if (v == null) {
            LayoutInflater vi = (LayoutInflater) this.getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            v = vi.inflate(R.layout.offer_each_item, null);
        }
        
        ViewHolder holder = (ViewHolder) v.getTag();
        
        if (holder == null) {
            holder = new ViewHolder(v);
            v.setTag(holder);
        }
        
        Offer offer = getItem(position);
        
        
        holder.offerImageView.setImageUrl(offer.getImageUrl(), MyVolley.getInstance(getContext()).getImageLoader());
        holder.briefOfferTextView.setText(offer.getOfferTitle());
        holder.extendedOfferTextView.setText(offer.getOfferDesc());
        
        return v;
    }
}

MainActivity

public class MainActivity extends Activity {
	
	private boolean mHasData = false;
    private boolean mInError = false;
	
	TextView headerTextView;
	ListView offersListView;
	
	final String URL = "http://172.20.1.246:3000/api/offer.json?param=new";
	private ArrayList<Offer> mOffers = new ArrayList<Offer>();
    public static CustomAdapter mAdapter;
    
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.offer_list);
		
		headerTextView = (TextView) findViewById(R.id.headerTextView);
		offersListView = (ListView) findViewById(R.id.offersListView);
		
		headerTextView.setText("NEW OFFERS");

		mAdapter = new CustomAdapter(this, 0, mOffers);
		//adapter.addAll(arrayOfOffers);
		offersListView.setAdapter(mAdapter);
	}
	
    @Override
    protected void onResume() {
        super.onResume();
        if (!mHasData && !mInError) {
            loadPage();
        }
    }
	
	private void loadPage() {
        RequestQueue queue = MyVolley.getInstance(getApplicationContext()).getRequestQueue();

        JsonObjectRequest myReq = new JsonObjectRequest(URL,
                                                        null,
                                                        createMyReqSuccessListener(),
                                                        createMyReqErrorListener());
        
        queue.add(myReq);
    }
    
    private Response.Listener<JSONObject> createMyReqSuccessListener() {
        return new Response.Listener<JSONObject>() {
            @Override
            public void onResponse(JSONObject response) {
                try {
                    JSONArray offers = response.getJSONArray("offers");
                    JSONObject offer;
                    for (int i = 0; i < offers.length(); i++) {
                        offer = offers.getJSONObject(i);
                        mOffers.add(new Offer(offer.getString("des"), offer.getString("des"),offer.getString("iu")));
                    }
                    mAdapter.notifyDataSetChanged();
                } catch (JSONException e) {
                    showErrorDialog(e.getMessage());
                }
            }
        };
    }

    private Response.ErrorListener createMyReqErrorListener() {
        return new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                showErrorDialog(error.getMessage());
            }
        };
    }

    private void showErrorDialog(String error) {
        mInError = true;
        
        AlertDialog.Builder b = new AlertDialog.Builder(this);
        b.setMessage("Error occured : " + error);
        b.show();
    }
	
	public void onListItemClick(ListView parent, View v, int position, long id){
		
	}
	
	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		// Inflate the menu; this adds items to the action bar if it is present.
		getMenuInflater().inflate(R.menu.main, menu);
		return true;
	}
}

MyVolley

public class MyVolley {
    private static MyVolley mInstance = null;
    private RequestQueue mRequestQueue;
    private ImageLoader mImageLoader;
    
    final int maxMemory = (int) (Runtime.getRuntime().maxMemory() / 1024);
    final int cacheSize = maxMemory / 8;
    
    private MyVolley(Context context){
        mRequestQueue = Volley.newRequestQueue(context);
        mImageLoader = new ImageLoader(this.mRequestQueue, new BitmapLruCache(cacheSize));
    }

    public static MyVolley getInstance(Context context){
        if(mInstance == null){
            mInstance = new MyVolley(context);
        }
        return mInstance;
    }

    public RequestQueue getRequestQueue(){
        return this.mRequestQueue;
    }

    public ImageLoader getImageLoader(){
        return this.mImageLoader;
    }
}

Offer

public class Offer {
	String offerTitle;
	String offerDesc;
	String imageUrl;
	private String errorImageUrl;
	
	
	public Offer(String oT,String oD, String iu){
		super();
		errorImageUrl = "Not to see.jpg";
		offerTitle = oT;
		offerDesc = oD;
		if (iu.equals(null)){
			iu = errorImageUrl;
		}else	
			imageUrl = iu;
			
	}
	
	public String getImageUrl(){
		return imageUrl;
	}
	
	public String getOfferTitle() {
		return offerTitle;
	}

	public String getOfferDesc() {
		return offerDesc;
	}	 
}