com.nolanofra.test.lazyLoader.MainActivity.java Source code

Introduction

Here is the source code for com.nolanofra.test.lazyLoader.MainActivity.java

Source

/**
 * @author FRANCESCO NOLANO
 *
 * 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.nolanofra.test.lazyLoader;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.params.BasicHttpParams;
import org.apache.http.params.HttpConnectionParams;
import org.apache.http.params.HttpParams;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import org.json.JSONTokener;

import android.app.ListActivity;
import android.graphics.Bitmap;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;

public class MainActivity extends ListActivity {

    public Bitmap placeholder;

    VideosArrayAdapter videoArrayAdapter;
    ArrayList<Video> videos;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.main);

        //ArrayList<Video> videos = getVideos ("https://gdata.youtube.com/feeds/api/users/radiobocconi/favorites?alt=jsonc&v=2&orderby=updated");
        new VideosAsyncTask().execute(
                "https://gdata.youtube.com/feeds/api/users/bocconitv/favorites?alt=jsonc&v=2&orderby=updated");

        videos = new ArrayList<Video>();
        videoArrayAdapter = new VideosArrayAdapter(this, R.layout.list_item, videos);
        setListAdapter(videoArrayAdapter);
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        if (videoArrayAdapter != null)
            videoArrayAdapter.clearCacheImageManager();
    }

    private class VideosAsyncTask extends AsyncTask<String, Void, Void> {
        @Override
        protected Void doInBackground(String... urls) {

            for (String url : urls)
                videos = getVideos(url);

            return null;
        }

        @Override
        protected void onPostExecute(Void x) {
            if (videos != null && !videos.isEmpty()) {
                videoArrayAdapter.clear();

                for (Video v : videos)
                    videoArrayAdapter.add(v);

                videoArrayAdapter.notifyDataSetChanged();
            }
        }
    }

    private ArrayList<Video> getVideos(String url) {
        ArrayList<Video> videos = new ArrayList<Video>();

        String jsonString = executeGet(url);

        JSONTokener tokener = new JSONTokener(jsonString);

        JSONObject objectMain = null;

        try {
            objectMain = new JSONObject(tokener);
        } catch (JSONException e) {
            e.printStackTrace();
        }

        JSONObject data = null;
        JSONArray itemsArray = null;
        try {
            data = objectMain.getJSONObject("data");
        } catch (JSONException e) {
            e.printStackTrace();
        }

        try {
            itemsArray = data.getJSONArray("items");

            for (int i = 0; i < itemsArray.length(); i++) {
                JSONObject videoRoot = itemsArray.getJSONObject(i);
                JSONObject video = videoRoot.getJSONObject("video");
                Video v = new Video();
                v.title = video.getString("title");
                if (!video.isNull("description"))
                    v.description = video.getString("description");
                if (!video.isNull("thumbnail")) {
                    JSONObject thumbnail = video.getJSONObject("thumbnail");
                    v.thumbnailHQDefault = thumbnail.getString("hqDefault");
                    v.thumbnailSQDefault = thumbnail.getString("sqDefault");
                }

                videos.add(v);
            }
        } catch (Exception e) {
            Log.d("error", e.getMessage());
        }

        return videos;
    }

    public String executeGet(String url) {
        int timeout = 5000;
        HttpGet get;
        InputStream instream;
        HttpParams httpParameters = new BasicHttpParams();
        HttpConnectionParams.setConnectionTimeout(httpParameters, timeout);
        HttpClient client = new DefaultHttpClient();

        String jsonText = "";
        get = new HttpGet(url);
        HttpResponse response = null;
        instream = null;

        try {
            try {
                response = client.execute(get);
            } catch (ClientProtocolException e1) {
                e1.printStackTrace();
            } catch (IOException e1) {
                e1.printStackTrace();
            }
            int status = response.getStatusLine().getStatusCode();

            if (status == HttpStatus.SC_OK) {
                HttpEntity entity = response.getEntity();

                try {
                    instream = entity.getContent();
                } catch (IllegalStateException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }

                jsonText = convertStreamToString(instream);
            }
        } catch (Exception e) {
        }
        return jsonText;
    }

    public String convertStreamToString(InputStream is) {
        BufferedReader reader = null;
        InputStreamReader inputStreamReader = new InputStreamReader(is);
        reader = new BufferedReader(inputStreamReader);
        //String encoding = inputStreamReader.getEncoding();

        StringBuilder sb = new StringBuilder();

        String line;
        try {
            while ((line = reader.readLine()) != null) {
                sb.append(line + "\n");
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                inputStreamReader.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        try {

            return sb.toString();

        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return "";
    }
}