HttpUtil.java

package com.eolwral.osmonitor.util;

import android.content.Context;
import android.graphics.Bitmap;
import android.support.v4.util.LruCache;

import com.android.volley.RequestQueue;
import com.android.volley.toolbox.ImageLoader;
import com.android.volley.toolbox.ImageLoader.ImageCache;
import com.android.volley.toolbox.JsonRequest;
import com.android.volley.toolbox.StringRequest;
import com.android.volley.toolbox.Volley;

//
// base on
// http://cypressnorth.com/mobile-application-development/setting-android-google-volley-imageloader-networkimageview/
//

public class HttpUtil {

  private static final String TAG = "Volley";

  private static HttpUtil mInstance = null;
  private RequestQueue mRequestQueue;
  private ImageLoader mImageLoader;

  private HttpUtil(Context context) {
    mRequestQueue = Volley.newRequestQueue(context);
    mImageLoader = new ImageLoader(this.mRequestQueue, new ImageLruCache());
  }

  private class ImageLruCache implements ImageCache {
    private final LruCache<String, Bitmap> mCache = new LruCache<String, Bitmap>(
        3);

    public void putBitmap(String url, Bitmap bitmap) {
      mCache.put(url, bitmap);
    }

    public Bitmap getBitmap(String url) {
      return mCache.get(url);
    }
  }

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

  public void addRequest(StringRequest newRequest) {

    if (newRequest == null)
      return;

    newRequest.setTag(TAG);
    mRequestQueue.add(newRequest);
    return;
  }

  public void addRequest(JsonRequest<?> newRequest) {

    if (newRequest == null)
      return;

    newRequest.setTag(TAG);
    mRequestQueue.add(newRequest);
    return;
  }

  public void cancelRequest() {
    mRequestQueue.cancelAll(TAG);
  }

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

}