Java tutorial
/** * Copyright 2013 Mani Selvaraj * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.mani.volleydemo; import java.io.File; import java.util.ArrayList; import java.util.List; import org.json.JSONArray; import org.json.JSONException; import org.json.JSONObject; import android.annotation.TargetApi; import android.app.ActionBar; import android.app.Activity; import android.app.ProgressDialog; import android.content.Context; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.net.Uri; import android.os.Build; import android.os.Bundle; import android.support.v4.util.LruCache; import android.view.LayoutInflater; import android.view.Menu; import android.view.View; import android.view.ViewGroup; import android.widget.BaseAdapter; import android.widget.Button; import android.widget.ImageView; import android.widget.ListView; import android.widget.TextView; import android.widget.Toast; import com.android.volley.Request; import com.android.volley.RequestQueue; import com.android.volley.Response; import com.android.volley.VolleyError; import com.android.volley.toolbox.DiskBasedCache; import com.android.volley.toolbox.ImageLoader; import com.android.volley.toolbox.ImageLoader.ImageCache; import com.android.volley.toolbox.ImageRequest; import com.android.volley.toolbox.JsonObjectRequest; import com.android.volley.toolbox.NetworkImageView; import com.android.volley.toolbox.Volley; import com.mani.volleydemo.toolbox.FadeInImageListener; import com.mani.volleydemo.util.BitmapUtil; /** * Demonstrates how to execute ImageRequest and NetworkImageView to download a image from a URL using Volley library. * @author Mani Selvaraj * */ public class NetworkImageActivity extends Activity { private Button mTrigger; private RequestQueue mVolleyQueue; private ListView mListView; private ImageView mImageView1; private ImageView mImageView2; private ImageView mImageView3; private NetworkImageView mNetworkImageView; private EfficientAdapter mAdapter; private ProgressDialog mProgress; private List<DataModel> mDataList; private ImageLoader mImageLoader; private final String TAG_REQUEST = "MY_TAG"; private class DataModel { private String mImageUrl; private String mTitle; public String getImageUrl() { return mImageUrl; } public void setImageUrl(String mImageUrl) { this.mImageUrl = mImageUrl; } public String getTitle() { return mTitle; } public void setTitle(String mTitle) { this.mTitle = mTitle; } } public class BitmapCache extends LruCache<String, Bitmap> implements ImageCache { public BitmapCache(int maxSize) { super(maxSize); } @Override public Bitmap getBitmap(String url) { return (Bitmap) get(url); } @Override public void putBitmap(String url, Bitmap bitmap) { put(url, bitmap); } } /* * Extends from DisckBasedCache --> Utility from volley toolbox. * Also implements ImageCache, so that we can pass this custom implementation * to ImageLoader. */ public class DiskBitmapCache extends DiskBasedCache implements ImageCache { public DiskBitmapCache(File rootDirectory, int maxCacheSizeInBytes) { super(rootDirectory, maxCacheSizeInBytes); } public DiskBitmapCache(File cacheDir) { super(cacheDir); } public Bitmap getBitmap(String url) { final Entry requestedItem = get(url); if (requestedItem == null) return null; return BitmapFactory.decodeByteArray(requestedItem.data, 0, requestedItem.data.length); } public void putBitmap(String url, Bitmap bitmap) { final Entry entry = new Entry(); /* //Down size the bitmap.If not done, OutofMemoryError occurs while decoding large bitmaps. // If w & h is set during image request ( using ImageLoader ) then this is not required. ByteArrayOutputStream baos = new ByteArrayOutputStream(); Bitmap downSized = BitmapUtil.downSizeBitmap(bitmap, 50); downSized.compress(Bitmap.CompressFormat.JPEG, 100, baos); byte[] data = baos.toByteArray(); entry.data = data ; */ entry.data = BitmapUtil.convertBitmapToBytes(bitmap); put(url, entry); } } JsonObjectRequest jsonObjRequest; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.networkimage_layout); actionBarSetup(); // Initialise Volley Request Queue. mVolleyQueue = Volley.newRequestQueue(this); int max_cache_size = 1000000; mImageLoader = new ImageLoader(mVolleyQueue, new DiskBitmapCache(getCacheDir(), max_cache_size)); //Memorycache is always faster than DiskCache. Check it our for yourself. //mImageLoader = new ImageLoader(mVolleyQueue, new BitmapCache(max_cache_size)); mDataList = new ArrayList<DataModel>(); mListView = (ListView) findViewById(R.id.image_list); mImageView1 = (ImageView) findViewById(R.id.imageview1); mImageView2 = (ImageView) findViewById(R.id.imageview2); mImageView3 = (ImageView) findViewById(R.id.imageview3); mNetworkImageView = (NetworkImageView) findViewById(R.id.networkimageview); mTrigger = (Button) findViewById(R.id.send_http); mAdapter = new EfficientAdapter(this); mListView.setAdapter(mAdapter); mTrigger.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { showProgress(); makeSampleHttpRequest(); } }); String testUrlToDownloadImage1 = "http://farm3.static.flickr.com/2833/9112621564_32bdfd58f3_q.jpg"; String testUrlToDownloadImage2 = "http://farm3.static.flickr.com/2848/9110760994_c8dc834397_q.jpg"; /* Demonstrating 3 ways of image downloading. 1 - Using ImageLoader and passing a url and imageListener. Additionally u can pass w & h 2 - User NetworkImageView and pass a url & ImageLoader The above 2 uses underlying 'ImageRequest' to initiate the download. 3 - Directly use ImageRequest api, by passing url, w & h, listeners, and BitmapConfig It has default retry mechanism i set to 2 maximum retries. */ //1) In case you are showing image as user icon normally 50x50, you can specify the width & height. mImageLoader.get(testUrlToDownloadImage1, ImageLoader.getImageListener(mImageView1, R.drawable.flickr, android.R.drawable.ic_dialog_alert), //You can specify width & height of the bitmap to be scaled down when the image is downloaded. 50, 50); //1 & 2) are almost same. Demonstrating you can apply animations while showing the downloaded image. // You can use nice entry animations while showing images in a listview.Uses custom implemented 'FadeInImageListener'. mImageLoader.get(testUrlToDownloadImage2, new FadeInImageListener(mImageView2, this)); //3) ImageRequest imgRequest = new ImageRequest(testUrlToDownloadImage2, new Response.Listener<Bitmap>() { @Override public void onResponse(Bitmap response) { mImageView3.setImageBitmap(response); } }, 0, 0, Bitmap.Config.ARGB_8888, new Response.ErrorListener() { @Override public void onErrorResponse(VolleyError error) { mImageView3.setImageResource(R.drawable.ic_launcher); } }); mVolleyQueue.add(imgRequest); //4) mNetworkImageView.setImageUrl(testUrlToDownloadImage1, mImageLoader); } @TargetApi(Build.VERSION_CODES.HONEYCOMB) private void actionBarSetup() { if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) { ActionBar ab = getActionBar(); ab.setTitle("ImageLoading"); } } public void onDestroy() { super.onDestroy(); System.out.println("######### onDestroy ######### " + mAdapter); } public void onStop() { super.onStop(); if (mProgress != null) mProgress.dismiss(); // Keep the list of requests dispatched in a List<Request<T>> mRequestList; /* for( Request<T> req : mRequestList) { req.cancel(); } */ //jsonObjRequest.cancel(); //( or ) //mVolleyQueue.cancelAll(TAG_REQUEST); } private void makeSampleHttpRequest() { String url = "http://api.flickr.com/services/rest"; Uri.Builder builder = Uri.parse(url).buildUpon(); builder.appendQueryParameter("api_key", "5e045abd4baba4bbcd866e1864ca9d7b"); builder.appendQueryParameter("method", "flickr.interestingness.getList"); builder.appendQueryParameter("format", "json"); builder.appendQueryParameter("nojsoncallback", "1"); jsonObjRequest = new JsonObjectRequest(Request.Method.GET, builder.toString(), null, new Response.Listener<JSONObject>() { @Override public void onResponse(JSONObject response) { System.out.println( "####### Response JsonObjectRequest SUCCESS ######## " + response.toString()); try { parseFlickrImageResponse(response); mAdapter.notifyDataSetChanged(); } catch (Exception e) { e.printStackTrace(); showToast("JSON parse error"); } stopProgress(); } }, new Response.ErrorListener() { @Override public void onErrorResponse(VolleyError error) { stopProgress(); System.out.println("####### onErrorResponse ########## " + error.getMessage()); showToast(error.getMessage()); } }); jsonObjRequest.setTag(TAG_REQUEST); mVolleyQueue.add(jsonObjRequest); } @Override public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.main, menu); return true; } private void showProgress() { mProgress = ProgressDialog.show(this, "", "Loading..."); } private void stopProgress() { mProgress.cancel(); } private void showToast(String msg) { Toast.makeText(NetworkImageActivity.this, msg, Toast.LENGTH_LONG).show(); } private void parseFlickrImageResponse(JSONObject response) throws JSONException { System.out.println("####### parseFlickrImageResponse ######## " + mAdapter); if (response.has("photos")) { try { JSONObject photos = response.getJSONObject("photos"); JSONArray items = photos.getJSONArray("photo"); mDataList.clear(); for (int index = 0; index < items.length(); index++) { JSONObject jsonObj = items.getJSONObject(index); String farm = jsonObj.getString("farm"); String id = jsonObj.getString("id"); String secret = jsonObj.getString("secret"); String server = jsonObj.getString("server"); String imageUrl = "http://farm" + farm + ".static.flickr.com/" + server + "/" + id + "_" + secret + "_t.jpg"; DataModel model = new DataModel(); model.setImageUrl(imageUrl); model.setTitle(jsonObj.getString("title")); mDataList.add(model); } } catch (Exception e) { e.printStackTrace(); } } } private class EfficientAdapter extends BaseAdapter { private LayoutInflater mInflater; public EfficientAdapter(Context context) { mInflater = LayoutInflater.from(context); } public int getCount() { return mDataList.size(); } public Object getItem(int position) { return position; } public long getItemId(int position) { return position; } public View getView(int position, View convertView, ViewGroup parent) { ViewHolder holder; System.out.println("####### getView ########### " + position); if (convertView == null) { convertView = mInflater.inflate(R.layout.networkimage_list_item, null); holder = new ViewHolder(); holder.image = (NetworkImageView) convertView.findViewById(R.id.image); holder.title = (TextView) convertView.findViewById(R.id.title); convertView.setTag(holder); } else { holder = (ViewHolder) convertView.getTag(); } holder.title.setText(mDataList.get(position).getTitle()); // As contrast to holder.image.setImageUrl(mDataList.get(position).getImageUrl(), mImageLoader); return convertView; } class ViewHolder { TextView title; NetworkImageView image; } } }