Develop Reference

Text in textview is not showing strings from java file - openweathermap

I am trying to use openweathermap to get basic data about weather and paste it into textview, but strings to which I am getting data doesn't refresh texts in textviews.
Code:
#SuppressLint("StaticFieldLeak")
class DownloadJSON extends AsyncTask<String, Void, String> {
#Override
protected String doInBackground(String... strings) {
URL url;
HttpURLConnection httpURLConnection;
InputStream inputStream;
InputStreamReader inputStreamReader;
StringBuilder result = new StringBuilder();
try {
url = new URL(strings[0]);
httpURLConnection = (HttpURLConnection) url.openConnection();
inputStream = httpURLConnection.getInputStream();
inputStreamReader = new InputStreamReader(inputStream);
int data = inputStreamReader.read();
while (data != -1) {
result.append((char) data);
}
} catch (IOException e) {
e.printStackTrace();
}
return result.toString();
}
}
txtCity = findViewById(R.id.txtCity);
txtTemp = findViewById(R.id.txtTemp);
DownloadJSON downloadJSON = new DownloadJSON();
try {
String result = downloadJSON.execute(url).get();
JSONObject jsonObject = new JSONObject(result);
String temp = jsonObject.getJSONObject("main").getString("temp");
String feel_like = jsonObject.getJSONObject("main").getString("feels_like");
txtCity.setText(City);
txtValueFeelLike.setText(feel_like);
txtTemp.setText(temp);
} catch (ExecutionException | InterruptedException | JSONException e) {
e.printStackTrace();
}
}
'''
String City = "Warsaw";
String url = "http://api.openweathermap.org/data/2.5/weather?q="+City+"&units=metric&appid=eace0bd8251cf6ab043ab9858b796256";
TextView txtCity, txtValueFeelLike, txtTemp;
What am I doing wrong?
Ok, I made a change, tried to make it from the scratch again, but now with onPostExecute(). Still nothing...
public class Weather {
private static final String OPEN_WEATHER_MAP_URL =
"http://api.openweathermap.org/data/2.5/weather?q=Warsaw&units=metric&appid=eace9b6857889076855263cfdb5707c0d00";
public interface AsyncResponse {
void processFinish(String output1, String output2, String output3, String output4, String output5, String output6);
}
public static class placeIdTask extends AsyncTask<String, Void, JSONObject> {
public AsyncResponse delegate = null;//Call back interface
#Override
protected JSONObject doInBackground(String... params) {
JSONObject jsonWeather = null;
try {
jsonWeather = getWeatherJSON();
} catch (Exception e) {
Log.d("Error", "Cannot process JSON results", e);
}
return jsonWeather;
}
#Override
public void onPostExecute(JSONObject json) {
try {
if(json != null){
JSONObject details = json.getJSONArray("weather").getJSONObject(0);
JSONObject main = json.getJSONObject("main");
DateFormat df = DateFormat.getDateTimeInstance();
String city = json.getString("name").toUpperCase(Locale.US) + ", " + json.getJSONObject("sys").getString("country");
String description = details.getString("description").toUpperCase(Locale.US);
#SuppressLint("DefaultLocale") String temperature = String.format("%.2f", main.getDouble("temp"))+ "°";
String humidity = main.getString("humidity") + "%";
String pressure = main.getString("pressure") + " hPa";
String updatedOn = df.format(new Date(json.getLong("dt")*1000));
delegate.processFinish(city, description, temperature, humidity, pressure, updatedOn);
}
} catch (JSONException e) {
}
}
}
public static JSONObject getWeatherJSON() {
try {
URL url = new URL(OPEN_WEATHER_MAP_URL);
HttpURLConnection connection =
(HttpURLConnection) url.openConnection();
BufferedReader reader = new BufferedReader(
new InputStreamReader(connection.getInputStream()));
StringBuilder json = new StringBuilder(1024);
String tmp = "";
while ((tmp = reader.readLine()) != null)
json.append(tmp).append("\n");
reader.close();
JSONObject data = new JSONObject(json.toString());
// This value will be 404 if the request was not
// successful
if (data.getInt("cod") != 200) {
return null;
}
return data;
} catch (Exception e) {
return null;
}
}}
And Main Activity:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
cityField = (TextView) findViewById(R.id.city_field);
updatedField = (TextView) findViewById(R.id.updated_field);
detailsField = (TextView) findViewById(R.id.details_field);
currentTemperatureField = (TextView) findViewById(R.id.current_temperature_field);
humidity_field = (TextView) findViewById(R.id.humidity_field);
pressure_field = (TextView) findViewById(R.id.pressure_field);
Weather.placeIdTask asyncTask = new Weather.placeIdTask() {
public void processFinish(String weather_city, String weather_description, String weather_temperature, String weather_humidity, String weather_pressure, String weather_updatedOn) {
cityField.setText(weather_city);
updatedField.setText(weather_updatedOn);
detailsField.setText(weather_description);
currentTemperatureField.setText(weather_temperature);
humidity_field.setText("Humidity: " + weather_humidity);
pressure_field.setText("Pressure: " + weather_pressure);
}
};
No idea what to do now.

Why is it not showing all the data?

I am creating this app which shows the latest news, which gets data from
https://newsapi.org/s/india-health-news-api
but it doesn't fetch all the data. Sometimes it just shows all but sometimes it just shows 2 or 3 news. Also, I don't see any log error message. What is the problem?
HealthNews.java
public class HealthNews extends AppCompatActivity {
private ArrayList urlList;
private NewsAdapter mNewsAdapter;
private static final String REQUEST_URL ="https://newsapi.org/v2/top-headlines?country=in&category=health&apiKey=3f7d99cdbb004766892bd239a4c099be";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_health_news);
Intent intent = getIntent();
HealthNews.NewsAsyncTask task = new HealthNews.NewsAsyncTask();
task.execute(REQUEST_URL);
urlList = QueryUtils.m;
ListView listView = (ListView)findViewById(R.id.listViewHealthNews);
mNewsAdapter = new NewsAdapter(this, new ArrayList<News>());
listView.setAdapter(mNewsAdapter);
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
//Toast.makeText(getApplicationContext(), ""+ a.get(position), Toast.LENGTH_SHORT).show();
Object url = urlList.get(position);
Uri uri = (Uri) Uri.parse((String) url); // missing 'http://' will cause crashed
Intent intent = new Intent(Intent.ACTION_VIEW, uri);
startActivity(intent);
}
});
}
private class NewsAsyncTask extends AsyncTask<String, Void, ArrayList<News>> {
ProgressDialog p;
#Override
protected ArrayList<News> doInBackground(String... urls) {
if (urls.length < 1 || urls[0] == null) {
return null;
}
ArrayList<News> result = QueryUtils.fetchEarthquakeData(urls[0]);
return result;
//return null;
}
#Override
protected void onPostExecute(ArrayList<News> data) {
mNewsAdapter.clear();
if (data != null && !data.isEmpty()) {
p.hide();
mNewsAdapter.addAll(data);
}
}
#Override
protected void onPreExecute() {
super.onPreExecute();
p = new ProgressDialog(HealthNews.this);
p.setMessage("Latest News...");
p.setIndeterminate(false);
p.show();
}
}
}
QueryUtils.java
private static final String LOG_TAG = "";
private QueryUtils(){
}
private static URL createUrl(String stringUrl) {
URL url = null;
try {
url = new URL(stringUrl);
} catch (MalformedURLException e) {
Log.e(LOG_TAG, "Problem building the URL ", e);
}
return url;
}
private static String makeHttpRequest(URL url) throws IOException {
String jsonResponse = "";
// If the URL is null, then return early.
if (url == null) {
return jsonResponse;
}
HttpURLConnection urlConnection = null;
InputStream inputStream = null;
try {
urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setReadTimeout(30000 /* milliseconds */);
urlConnection.setConnectTimeout(60000 /* milliseconds */);
urlConnection.setRequestMethod("GET");
urlConnection.connect();
if (urlConnection.getResponseCode() == 200) {
inputStream = urlConnection.getInputStream();
jsonResponse = readFromStream(inputStream);
} else {
Log.e(LOG_TAG, "Error response code: " + urlConnection.getResponseCode());
}
} catch (IOException e) {
Log.e(LOG_TAG, "Problem retrieving the earthquake JSON results.", e);
} finally {
if (urlConnection != null) {
urlConnection.disconnect();
}
if (inputStream != null) {
inputStream.close();
}
}
return jsonResponse;
}
private static String readFromStream(InputStream inputStream) throws IOException {
StringBuilder output = new StringBuilder();
if (inputStream != null) {
InputStreamReader inputStreamReader = new InputStreamReader(inputStream, Charset.forName("UTF-8"));
BufferedReader reader = new BufferedReader(inputStreamReader);
String line = reader.readLine();
while (line != null) {
output.append(line);
line = reader.readLine();
}
}
return output.toString();
}
static ArrayList<String> m = new ArrayList<String>();
public static ArrayList<News> extractNews(String SAMPLE_JSON){
if (TextUtils.isEmpty(SAMPLE_JSON)) {
return null;
}
ArrayList<News> news = new ArrayList<News>();
try {
JSONObject jsonObject1 = new JSONObject(SAMPLE_JSON);
JSONArray baseJSONArray = jsonObject1.getJSONArray("articles");
for (int i = 0; i < baseJSONArray.length(); i++) {
JSONObject jsonObject = baseJSONArray.getJSONObject(i);
JSONObject source = jsonObject.getJSONObject("source");
String name = source.getString("name");
String article = jsonObject.getString("title");
String url1 = jsonObject.getString("url");
String img = jsonObject.getString("urlToImage");
URL url = new URL(img);
Bitmap image = BitmapFactory.decodeStream(url.openConnection().getInputStream());
News a = new News(image, article);
news.add(a);
m.add(url1);
}
} catch (JSONException j) {
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return news;
}
public static ArrayList<News> fetchEarthquakeData(String requestUrl) {
URL url = createUrl(requestUrl);
String jsonResponse = null;
try {
jsonResponse = makeHttpRequest(url);
} catch (IOException e) {
Log.e(LOG_TAG, "Problem making the HTTP request.", e);
}
ArrayList<News> news = extractNews(jsonResponse);
return news;
}

I went though your code and found some issues.
Some bad practices i found in your code are:
You are adding your urls in separate list with static specifier. Instead of this you should add the url variable in your News model directly. And you can directly retrieve the whole News model inside ListView > setOnItemClickListener.
You are creating Bitmap for all your images. It may cause OOM Exception. You should use any Image loading library instead.
I have fixed that all issues and created working code. Please do required changes which you want at your end.
HealthNews.java
public class HealthNews extends AppCompatActivity {
private Context context;
private NewsAdapter mNewsAdapter;
private ArrayList<News> listNews;
private static final String REQUEST_URL = "https://newsapi.org/v2/top-headlines?country=in&category=health&apiKey=3f7d99cdbb004766892bd239a4c099be";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.health_news);
context = this;
ListView list_news = findViewById(R.id.list_news);
listNews = new ArrayList<>();
mNewsAdapter = new NewsAdapter(context, listNews);
list_news.setAdapter(mNewsAdapter);
list_news.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
try {
News selNews = (News) parent.getAdapter().getItem(position);
startActivity(new Intent(Intent.ACTION_VIEW, Uri.parse(selNews.getUrl())));
} catch (Exception e) {
// Missing 'http://' or 'https://' will cause crash
e.printStackTrace();
}
}
});
new NewsAsyncTask().execute(REQUEST_URL);
}
private class NewsAsyncTask extends AsyncTask<String, Void, ArrayList<News>> {
private ProgressDialog p;
#Override
public void onPreExecute() {
super.onPreExecute();
p = new ProgressDialog(context);
p.setMessage("Latest News...");
p.setIndeterminate(false);
p.show();
}
#Override
public ArrayList<News> doInBackground(String... urls) {
return QueryUtils.fetchEarthquakeData(urls[0]);
}
#Override
public void onPostExecute(ArrayList<News> newsList) {
super.onPostExecute(newsList);
listNews.addAll(newsList);
p.hide();
mNewsAdapter.notifyDataSetChanged();
}
}
}
QueryUtils.java
public class QueryUtils {
public static ArrayList<News> fetchEarthquakeData(String apiUrl) {
ArrayList<News> listNews = new ArrayList<>();
try {
URL url = new URL(apiUrl);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setReadTimeout(30000);
conn.setConnectTimeout(60000);
conn.setRequestMethod("GET");
conn.connect();
int responseCode = conn.getResponseCode();
InputStream iStream;
if (responseCode == HttpURLConnection.HTTP_OK)
iStream = conn.getInputStream();
else
iStream = conn.getErrorStream();
BufferedReader br = new BufferedReader(new InputStreamReader(iStream));
StringBuilder response = new StringBuilder();
String line;
while ((line = br.readLine()) != null) {
response.append(line);
}
String jsonResponse = response.toString();
if (TextUtils.isEmpty(jsonResponse))
return null;
JSONObject jsonObject1 = new JSONObject(jsonResponse);
JSONArray baseJSONArray = jsonObject1.getJSONArray("articles");
for (int i = 0; i < baseJSONArray.length(); i++) {
JSONObject jsonObject = baseJSONArray.getJSONObject(i);
JSONObject source = jsonObject.getJSONObject("source");
News news = new News();
news.setArticle(jsonObject.optString("title"));
news.setUrl(jsonObject.optString("url"));
news.setUrlToImage(jsonObject.optString("urlToImage"));
listNews.add(news);
}
} catch (JSONException e) {
e.printStackTrace();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return listNews;
}
}
News.java (Model)
public class News {
private String article;
private String url;
private String urlToImage;
public News() {
this.article = "";
this.url = "";
this.urlToImage = "";
}
public String getArticle() {
return article;
}
public void setArticle(String article) {
this.article = article;
}
public String getUrl() {
return url;
}
public void setUrl(String url) {
this.url = url;
}
public String getUrlToImage() {
return urlToImage;
}
public void setUrlToImage(String urlToImage) {
this.urlToImage = urlToImage;
}
}
NewsAdapter.java (Change your item layout as per your code)
public class NewsAdapter extends BaseAdapter {
private Context context;
private LayoutInflater mInflater;
private List<News> listNews;
public NewsAdapter(Context context, List<News> listNews) {
this.context = context;
this.listNews = listNews;
mInflater = LayoutInflater.from(context);
}
#Override
public int getCount() {
return listNews.size();
}
#Override
public News getItem(int position) {
return listNews.get(position);
}
#Override
public long getItemId(int position) {
return position;
}
private class ViewHolder {
private ImageView item_img_news;
private TextView item_txt_article;
}
#SuppressLint("InflateParams")
#Override
public View getView(final int position, View convertView, ViewGroup parent) {
final ViewHolder holder;
if (convertView == null) {
convertView = mInflater.inflate(R.layout.item_news, null);
holder = new ViewHolder();
holder.item_img_news = convertView.findViewById(R.id.item_img_news);
holder.item_txt_article = convertView.findViewById(R.id.item_txt_article);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
final News news = getItem(position);
holder.item_txt_article.setText(news.getArticle());
Glide.with(context).load(news.getUrlToImage()).into(holder.item_img_news);
return convertView;
}
}
app > build.gradle
implementation 'com.github.bumptech.glide:glide:4.9.0'

retrieve arraylist from AsyncTask class object after the doInBackground method is finished

i have classes in my projects that only does the server operations such as getting and putting data. i have class which populating list and then method to get this list. the problem is that i'm calling the "getList" method and the background operation hasent finished then i get null from the "getList" method
this is my AsyncTask class, as you can see the "getList" suppose to give me the list completed
public class GetRoomatesListActivity extends AsyncTask<String, String, String> {
private ArrayList<RoomateModel> tmpList;
private ArrayList<RoomateModel> completeList;
DBHelper db;
Context context;
public GetRoomatesListActivity(Context context){
this.context = context;
}
#Override
protected String doInBackground(String... params) {
db = DBHelper.getInstance(context);
HttpURLConnection connection = null;
BufferedReader reader = null;
tmpList = new ArrayList<RoomateModel>();
try {
URL url = new URL(params[0]);
connection = (HttpURLConnection) url.openConnection();
connection.connect();
InputStream stream = connection.getInputStream();
reader = new BufferedReader(new InputStreamReader(stream));
StringBuffer buffer = new StringBuffer();
String line = "";
while ((line = reader.readLine()) != null) {
buffer.append(line);
}
String finalJson = buffer.toString();
JSONObject parentObject = new JSONObject(finalJson);
JSONArray parentArray = parentObject.getJSONArray("result");//creates array of Roomates of the selected apartment
for (int i = 0; i < parentArray.length(); i++) {
JSONObject finalObject = parentArray.getJSONObject(i);//get the cuttent json object which is representaion of roomate object
String Fname = finalObject.getString("firstName");
String Lname = finalObject.getString("lastName");
String phone = finalObject.getString("phone");
RoomateModel item = new RoomateModel(Fname, Lname, phone);//creates roomates model with the current item data from the array
tmpList.add(item);//adds the roomate to the list of roomates
//add the roomates to local data base
db.addRoomate(item,apartment);
}
return null;
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
} finally {
if (connection != null) {
connection.disconnect();
}
try {
if (reader != null) {
reader.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
return null;
}
#Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
completeList = tmpList;
}
public ArrayList<RoomateModel> getList(){
return completeList;
}
}
and this is the class which im trying to get the list to in order to use it but its retrieving null
public class roomatesScreen extends Activity {
ListView items;
ArrayList<RoomateModel> list; //list to compare with the list rerived from GetRoomatesListActivity
RoomatesAdapter adapter;
DBHelper db;
ApartmentModel apartment;
SharedPreferences preferences;
GetRoomatesListActivity r;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.roomates_list);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
items = (ListView) findViewById(R.id.roomatesList);
db = DBHelper.getInstance(this);
Bundle bundle = getIntent().getExtras();
int number = bundle.getInt("number");
apartment = new ApartmentModel(number);// creates apartment model with the user's apartment number
final String num = Integer.toString(number);
r = new GetRoomatesListActivity(this);
r.execute("this is the link to my query" + num);
list = r.getList(); //here list is null
adapter = new RoomatesAdapter(roomatesScreen.this, list);
items.setAdapter(adapter);//here application crushes because of nullPointerExpeption

The best way is to perform the update on UI is in PostExecute method of AsyncTask..
At the time you are accessing it, the control is in the doInBackground method. So your list is null at that time.
put this
#Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
adapter = new RoomatesAdapter(roomatesScreen.this, tmpList);
items.setAdapter(adapter);/
}
into the onPostExecute().
2nd solution
Initialize the list when you are setting it to adapter. like:
list = new ArrayList();
and rest work (update the list and call notifyDataSetChanged() on adapter object) in onPostExecute().

Change doInBackground() method return type
public class GetRoomatesListActivity extends AsyncTask<String, String, ArrayList<Object>> {
private ArrayList<RoomateModel> tmpList;
private ArrayList<RoomateModel> completeList;
DBHelper db;
Context context;
public GetRoomatesListActivity(Context context){
this.context = context;
}
#Override
protected ArrayList<Object> doInBackground(String... params) {
db = DBHelper.getInstance(context);
HttpURLConnection connection = null;
BufferedReader reader = null;
tmpList = new ArrayList<RoomateModel>();
try {
URL url = new URL(params[0]);
connection = (HttpURLConnection) url.openConnection();
connection.connect();
InputStream stream = connection.getInputStream();
reader = new BufferedReader(new InputStreamReader(stream));
StringBuffer buffer = new StringBuffer();
String line = "";
while ((line = reader.readLine()) != null) {
buffer.append(line);
}
String finalJson = buffer.toString();
JSONObject parentObject = new JSONObject(finalJson);
JSONArray parentArray = parentObject.getJSONArray("result");//creates array of Roomates of the selected apartment
for (int i = 0; i < parentArray.length(); i++) {
JSONObject finalObject = parentArray.getJSONObject(i);//get the cuttent json object which is representaion of roomate object
String Fname = finalObject.getString("firstName");
String Lname = finalObject.getString("lastName");
String phone = finalObject.getString("phone");
RoomateModel item = new RoomateModel(Fname, Lname, phone);//creates roomates model with the current item data from the array
tmpList.add(item);//adds the roomate to the list of roomates
//add the roomates to local data base
db.addRoomate(item,apartment);
}
return null;
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
} finally {
if (connection != null) {
connection.disconnect();
}
try {
if (reader != null) {
reader.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
return null;
}
#Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
completeList = tmpList;
}
public ArrayList<RoomateModel> getList(){
return completeList;
}
}

Imageview not showing unless rotate or resume

I am working on my movie project which fetch movie poster from URL, and then putting them into a gridview. I use asynctask to fetch JSON and the parse the url within the json file. However, when I launch my app, the grid is all empty and doing nothing until I rotate my screen or resume my app. Once I rotate my screen or resume my app. It shows all picture. I remove my api key on my code here.
public class FetchMovieTask extends AsyncTask<Void, Void, ArrayList<String>> {
private final String LOG_TAG = FetchMovieTask.class.getSimpleName();
#Override
protected ArrayList<String> doInBackground(Void... params) {
String api_key = "";
HttpURLConnection urlConnection = null;
BufferedReader reader = null;
String movieJsonStr = null;
try {
Uri.Builder builder = new Uri.Builder();
builder.scheme("http")
.authority("api.themoviedb.org")
.appendPath("3")
.appendPath("discover")
.appendPath("movie")
.appendQueryParameter("api_key", api_key);
String myUrl = builder.build().toString();
URL Url = new URL(myUrl);
Log.v(LOG_TAG, myUrl);
// Create the request to OpenWeatherMap, and open the connection
urlConnection = (HttpURLConnection) Url.openConnection();
urlConnection.setRequestMethod("GET");
urlConnection.connect();
// Read the input stream into a String
InputStream inputStream = urlConnection.getInputStream();
StringBuffer buffer = new StringBuffer();
if (inputStream == null) {
// Nothing to do.
movieJsonStr = null;
}
reader = new BufferedReader(new InputStreamReader(inputStream));
String line;
while ((line = reader.readLine()) != null) {
// Since it's JSON, adding a newline isn't necessary (it won't affect parsing)
// But it does make debugging a *lot* easier if you print out the completed
// buffer for debugging.
buffer.append(line + "\n");
}
if (buffer.length() == 0) {
// Stream was empty. No point in parsing.
movieJsonStr = null;
}
movieJsonStr = buffer.toString();
Log.v("KPN", movieJsonStr);
} catch (IOException e) {
Log.e(LOG_TAG, "Error ", e);
// If the code didn't successfully get the weather data, there's no point in attempting
// to parse it.
movieJsonStr = null;
return null;
} finally {
if (urlConnection != null) {
urlConnection.disconnect();
}
if (reader != null) {
try {
reader.close();
} catch (final IOException e) {
Log.e(LOG_TAG, "Error closing stream", e);
}
}
}
try {
MovieURL = getPosterUrlFromJson(movieJsonStr);
} catch (JSONException e) {
Log.e(LOG_TAG, e.getMessage(), e);
e.printStackTrace();
}
return null;
}
}
private ArrayList<String> getPosterUrlFromJson(String forcastMovieStr)
throws JSONException {
final String OWM_PosterUrl = "poster_path";
final String OWM_releaseDate = "release_date";
final String OWM_overview = "overview";
final String OWM_vote_average = "vote_average";
final String OWM_original_title = "original_title";
final String OWM_results = "results";
JSONObject movieJson = new JSONObject(forcastMovieStr);
JSONArray movieArray = movieJson.getJSONArray(OWM_results);
ArrayList<String> resultStrs = new ArrayList<>();
String posterurl = "http://image.tmdb.org/t/p/w185/";
for (int i = 0; i < movieArray.length(); i++) {
// For now, using the format "Day, description, hi/low"
String title;
String overview;
String poster;
// Get the JSON object for movie poster
JSONObject moveposter = movieArray.getJSONObject(i);
poster = moveposter.getString(OWM_PosterUrl);
resultStrs.add(i,posterurl + poster);
}
return resultStrs;
}
protected void onPostExecute(ArrayList<String> strings) {
MovieURL.clear();
for (String s : strings) {
MovieURL.add(s);
}
}
Main:
public class MainActivity extends AppCompatActivity {
public static ArrayList<String> MovieURL = new ArrayList();
public static ImageListAdapter mImageListAdapter;
public GridView gridview;
#Override
protected void onStart() {
super.onStart();
new FetchMovieTask().execute();
mImageListAdapter = new ImageListAdapter(this,MovieURL);
gridview.setAdapter(mImageListAdapter);
gridview.invalidateViews();
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
gridview = (GridView) findViewById(R.id.gridview);
}
private void updateMovieURL(){
new FetchMovieTask().execute();
gridview.invalidateViews();
}
ImagelistAdapter class
public class ImageListAdapter extends ArrayAdapter {
private Context context;
private LayoutInflater inflater;
private ArrayList<String> imageUrls;
public ImageListAdapter(Context context, ArrayList <String> imageUrls) {
super(context, R.layout.image_view, imageUrls);
this.context = context;
this.imageUrls = imageUrls;
inflater = LayoutInflater.from(context);
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
if (null == convertView) {
convertView = inflater.inflate(R.layout.image_view, parent, false);
}
Picasso.with(context).load(imageUrls.get(position))
.placeholder(R.drawable.loading)
.into((ImageView) convertView);
return convertView;
}
}
THanks guys

In postExecute do this:
protected void onPostExecute(ArrayList<String> strings) {
MovieURL.clear();
for (String s : strings) {
MovieURL.add(s);
}
mImageListAdapter.notifyDataSetChanged();
}

I found my problem on the asynctask, I didnt override the onPostExecute method. After I override my onPostExecute, I initial my grid view
#Override
protected void onPostExecute(ArrayList<String> strings) {
super.onPostExecute(strings);
mImageListAdapter = new ImageListAdapter(MainActivity.this, MovieURL);
gridview.setAdapter(mImageListAdapter);
}

Android Async Task Freezes UI Completely

I have an Async task that loads information from the server and displays data on the UI. Suddenly the async task downloads the data and formats the JSON data fine but it would freeze the UI completely.
Here is the base download class
public class GetRawData {
private static String LOG_TAG = GetRawData.class.getSimpleName();
private String mRawURL;
private List<NameValuePair> mRawParams = null;
private String mRawData;
private DownloadStatus mDownloadStatus;
public GetRawData(String mRawURL) {
this.mRawURL = mRawURL;
this.mRawParams = null;
this.mDownloadStatus = DownloadStatus.IDLE;
}
public String getRawData() {
return mRawData;
}
public void setRawURL(String mRawURL) {
this.mRawURL = mRawURL;
}
public List<NameValuePair> getRawParams() {
return mRawParams;
}
public void setRawParams(List<NameValuePair> mParams) {
this.mRawParams = mParams;
}
public DownloadStatus getDownloadStatus() {
return mDownloadStatus;
}
public void reset() {
this.mRawURL = null;
this.mRawData = null;
this.mDownloadStatus = DownloadStatus.IDLE;
}
public void execute() {
this.mDownloadStatus = DownloadStatus.PROCESSING;
DownloadRawData mDownloadRawData = new DownloadRawData();
mDownloadRawData.execute(mRawURL);
}
public class DownloadRawData extends AsyncTask<String, Void, String> {
#Override
protected String doInBackground(String... params) {
// Create URL and Reader instances.
HttpURLConnection urlConnection = null;
BufferedReader reader = null;
//If no parameter has been provided, return null.
if (params == null)
return null;
try {
// Get URL entered by the user.
URL mURL = new URL(params[0]);
urlConnection = (HttpURLConnection) mURL.openConnection();
urlConnection.setDoOutput(true);
urlConnection.setRequestMethod("POST");
urlConnection.setUseCaches(false);
urlConnection.setConnectTimeout(10000);
urlConnection.setReadTimeout(10000);
urlConnection.setRequestProperty("Content-Type","application/json");
//urlConnection.setRequestProperty("Host", "android.schoolportal.gr");
urlConnection.connect();
// validate and add parameters if available.
if (mRawParams != null && mRawParams.size()>0){
JSONObject jsonParam = new JSONObject();
for (NameValuePair pair : mRawParams) {
jsonParam.put(pair.getName().toString(), pair.getValue().toString());
}
String jsonparams = jsonParam.toString();
// Send POST output.
DataOutputStream printout;
printout = new DataOutputStream(urlConnection.getOutputStream());
printout.writeBytes(jsonparams);
printout.flush();
printout.close();
}
int HttpResult =urlConnection.getResponseCode();
StringBuffer buffer = new StringBuffer();
if(HttpResult ==HttpURLConnection.HTTP_OK){
InputStream inputStream = urlConnection.getInputStream();
if (inputStream == null) {
return null;
}
reader = new BufferedReader(new InputStreamReader(inputStream));
String line;
while ((line = reader.readLine()) != null) {
buffer.append(line + "\n");
}
System.out.println(""+buffer.toString());
}else{
InputStream errorStream = urlConnection.getErrorStream();
if (errorStream == null) {
return null;
}
reader = new BufferedReader(new InputStreamReader(errorStream));
String line;
while ((line = reader.readLine()) != null) {
buffer.append(line + "\n");
}
System.out.println(urlConnection.getResponseMessage());
}
return buffer.toString();
} catch (IOException e) {
Log.d("IOException", e.toString());
return null;
} catch (JSONException j) {
Log.d("JSONException", j.toString());
return null;
} finally {
if (urlConnection != null) {
urlConnection.disconnect();
}
if (reader != null) {
try {
reader.close();
} catch (IOException e) {
Log.d("IOException", "unable to close the reader");
}
}
}
}
#Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
mRawData = result;
//Log.d("onPostExecute", result);
if (mRawData == null) {
if (mRawURL == null) {
mDownloadStatus = DownloadStatus.NOT_INITIALIZED;
} else {
mDownloadStatus = DownloadStatus.FAILED_OR_EMPTY;
}
} else {
mDownloadStatus = DownloadStatus.PROCESSED;
}
}
private String getQuery(List<NameValuePair> params) throws UnsupportedEncodingException {
StringBuilder result = new StringBuilder();
boolean first = true;
for (NameValuePair pair : params) {
if (first)
first = false;
else
result.append("&");
result.append(URLEncoder.encode(pair.getName(), "UTF-8"));
result.append("=");
result.append(URLEncoder.encode(pair.getValue(), "UTF-8"));
}
return result.toString();
}
}
}
enum DownloadStatus {
IDLE,
PROCESSING,
NOT_INITIALIZED,
FAILED_OR_EMPTY,
PROCESSED
}
Here is the specific data formatting class the extends above class
public class GetJobCardJsonData extends GetRawData {
private static String LOG_TAG = GetAuthenticationJsonData.class.getSimpleName();
private static String JOBCARD_SERVICE_URL = "http://www.appservice.com/appservice/jobcardinfoservice.asmx/GetJobCardInfo";
private List<JobCard> mJobCardList;
private CarcalDownloadListener mListener;
public GetJobCardJsonData(String CurrentDate, int DealershipID) {
super(null);
List<NameValuePair> mParams = new ArrayList<NameValuePair>();
mParams.add(new BasicNameValuePair("JobCardDate", CurrentDate));
mParams.add(new BasicNameValuePair("DealershipID", String.valueOf(DealershipID)));
this.setRawParams(mParams);
}
public List<JobCard> getJobCardList() {
return mJobCardList;
}
public void getjobcards() {
super.setRawURL(JOBCARD_SERVICE_URL);
DownloadJobCardJsonData mDownloadJobCardJsonData = new DownloadJobCardJsonData();
mDownloadJobCardJsonData.execute(JOBCARD_SERVICE_URL);
}
public void setOnCarcalDownloadListener(CarcalDownloadListener onCarcalDownloadListener) {
this.mListener = onCarcalDownloadListener;
}
private void processResult() {
if (getDownloadStatus() != DownloadStatus.PROCESSED) {
Log.e(LOG_TAG, "Error Downloading the raw file.");
return;
}
if (mJobCardList == null){
mJobCardList = new ArrayList<JobCard>();
}
final String JOBCARD_JOBCARDID = "JobCardID";
final String JOBCARD_GETSTOCKNUMBER_WITH_DELIVERYTIME = "StockNumberWithDeliveryTime";
final String JOBCARD_CUSTOMERNAME = "CustomerName";
final String JOBCARD_MODELNUMBER = "ModelNumber";
final String JOBCARD_COLOR = "Color";
final String JOBCARD_SALEEXECUTIVE = "SaleExecutive";
final String JOBCARD_ORDERSTATUS = "OrderStatus";
final String JOBCARD_SHOWROOMSTATUS = "ShowRoomStatus";
try {
JSONArray jsonArray = new JSONArray(getRawData());
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject jobcarditem = jsonArray.optJSONObject(i);
Long JOBCARDID = jobcarditem.getLong(JOBCARD_JOBCARDID);
String STOCKWITHDELIVERY = jobcarditem.getString(JOBCARD_GETSTOCKNUMBER_WITH_DELIVERYTIME);
String CUSTOMERNAME = jobcarditem.getString(JOBCARD_CUSTOMERNAME);
String MODELNUMBER = jobcarditem.getString(JOBCARD_MODELNUMBER);
String COLOR = jobcarditem.getString(JOBCARD_COLOR);
String SALEEXECUTIVE = jobcarditem.getString(JOBCARD_SALEEXECUTIVE);
int ORDERSTATUS = jobcarditem.getInt(JOBCARD_ORDERSTATUS);
int SHOWROOMSTATUS = jobcarditem.getInt(JOBCARD_SHOWROOMSTATUS);
JobCard mJobCard = new JobCard(JOBCARDID, STOCKWITHDELIVERY, CUSTOMERNAME, MODELNUMBER, COLOR, SALEEXECUTIVE, ORDERSTATUS, SHOWROOMSTATUS);
mJobCardList.add(mJobCard);
}
} catch (JSONException jsone) {
jsone.printStackTrace();
Log.e(LOG_TAG, "Error processing json data.");
}
}
public class DownloadJobCardJsonData extends DownloadRawData {
#Override
protected String doInBackground(String... params) {
return super.doInBackground(params[0]);
}
#Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
processResult();
mListener.OnDownloadCompleted();
}
}
}
Here is the code that is called on the activity
private JobCardRecyclerViewAdapter mJobCardRecyclerViewAdapter;
private GetJobCardJsonData mGetJobCardJsonData;
SessionManager session;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_job_card_calender);
activateToolbarWithHomeEnabled();
String formattedDate="";
if (session.getCurrentDate() == ""){
Calendar c = Calendar.getInstance();
SimpleDateFormat df = new SimpleDateFormat("MM/dd/yyyy");
formattedDate = df.format(c.getTime());
currentDateTextView.setText(formattedDate);
}else {
formattedDate = session.getCurrentDate();
currentDateTextView.setText(formattedDate);
}
// Fetch data for current date.
mGetJobCardJsonData = new GetJobCardJsonData(formattedDate, session.getDealershipID());
mGetJobCardJsonData.getjobcards();
mGetJobCardJsonData.setOnCarcalDownloadListener(new CarcalDownloadListener() {
#Override
public void OnDownloadCompleted() {
List<JobCard> mJobCards = mGetJobCardJsonData.getJobCardList();
mJobCardRecyclerViewAdapter = new JobCardRecyclerViewAdapter(mJobCards, JobCardCalenderActivity.this);
mRecyclerView.setAdapter(mJobCardRecyclerViewAdapter);
}
});
}
Can anyone help on what i am doing wrong that is freezing the UI. It was working fine before and has started to freeze the UI suddenly.

I was able to fix the issue, the problem was not with Async task but with the layout. I accidently wrapped the recycler view with scroll view. which was causing the UI to freeze. Looks weird that a scroll view caused the whole UI thread to freeze. but here is my solution
<ScrollView
android:layout_width="match_parent"
android:layout_height="match_parent">
<view
android:id="#+id/jobCardRecyclerView"
class="android.support.v7.widget.RecyclerView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="#id/jobCardHeader"
android:scrollbars="vertical"></view>
</ScrollView>
Changed it to
<view
android:id="#+id/jobCardRecyclerView"
class="android.support.v7.widget.RecyclerView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="#id/jobCardHeader"
android:scrollbars="vertical"></view>
hope it will be helpful for others facing same problem.