Develop Reference

How to fetch data from net faster and display in listView?

I have a news app. My app takes so much time to fetch data from server and display it on the listView.But i have seen that apps like flipboard,facebook and Game News which has more data to fetch than mine does it faster.I think my app loads the entire data and displays the entire list together.Is there a way to display the list such that it loads the items in listView one by one?I do the fetching using a AsyncTaskLoader in the background.Also how to display a large list of news like 100 in a list .
MainActivity:
package com.example.android.gametalks;
import android.app.LoaderManager;
import android.content.Intent;
import android.content.Loader;
import android.net.Uri;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity implements LoaderManager.LoaderCallbacks<List<GameNews>> {
//IGN url
final String ign_url = "https://newsapi.org/v1/articles?source=ign&sortBy=top&apiKey=679f6fb918d34343b18590ca70f7fcde";
final String google_url = " https://newsapi.org/v1/articles?source=google-news&sortBy=top&apiKey=679f6fb918d34343b18590ca70f7fcde";
final String engadget_url = "https://newsapi.org/v1/articles?source=engadget&sortBy=top&apiKey=679f6fb918d34343b18590ca70f7fcde";
GameAdapter adapter ;
private View progressBar;
final private int game_loader = 0;
ArrayList<String> urls = new ArrayList<>();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
urls.add(ign_url);
urls.add(google_url);
urls.add(engadget_url);
//Getting listView
ListView gameListView = (ListView) findViewById(R.id.listView);
//progress bar finding
progressBar = findViewById(R.id.progress_bar);
ArrayList<GameNews> gameList = new ArrayList<>();
//Making a new arrayAdapter
adapter = new GameAdapter(this,gameList);
//Connecting ArrayAdapter to ListView
gameListView.setAdapter(adapter);
getLoaderManager().initLoader(game_loader, null, this);
//ListView item click listner
gameListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
GameNews currentEarthquake = adapter.getItem(i);
String url = currentEarthquake.getUrl();
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setData(Uri.parse(url));
startActivity(intent);
}
});
}
#Override
public Loader<List<GameNews>> onCreateLoader(int i, Bundle bundle) {
return new GameLoader(this,urls);
}
#Override
public void onLoadFinished(Loader<List<GameNews>> loader, List<GameNews> games) {
progressBar.setVisibility(View.INVISIBLE);
adapter.clear();
if(games == null)
{
return;
}
adapter.addAll(games);
}
#Override
public void onLoaderReset(Loader<List<GameNews>> loader) {
adapter.clear();
}
}
GameLoader:
package com.example.android.gametalks;
import android.content.AsyncTaskLoader;
import android.content.Context;
import java.util.ArrayList;
import java.util.List;
/**
* Created by apple on 9/8/17.
*/
public class GameLoader extends AsyncTaskLoader<List<GameNews>> {
private ArrayList<String> Urls = new ArrayList<>();
public GameLoader(Context context, ArrayList<String> Url) {
super(context);
Urls = Url;
}
#Override
protected void onStartLoading()
{
forceLoad();
}
#Override
public List<GameNews> loadInBackground() {
if(Urls == null)
{
return null;
}
// Perform the HTTP request for earthquake data and process the response.
List<GameNews> games = QueryUtils.FetchEarthquakeData(Urls);
return games;
}
}
QueryUtils(Here the network fetching takes place):
package com.example.android.gametalks;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.util.Log;
import android.widget.ListView;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.nio.charset.Charset;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
/**
* Helper methods related to requesting and receiving earthquake data from USGS.
*/
public final class QueryUtils {
private static final String LOG_TAG = QueryUtils.class.getSimpleName();
/**
* Create a private constructor because no one should ever create a {#link QueryUtils} object.
* This class is only meant to hold static variables and methods, which can be accessed
* directly from the class name QueryUtils (and an object instance of QueryUtils is not needed).
*/
private QueryUtils() {
}
public static List<GameNews> FetchEarthquakeData(ArrayList<String> Url) {
List<GameNews> games ;
List<GameNews> Total = new ArrayList<>();
URL url;
Log.d(LOG_TAG,Url.get(0));
for(int i = 0 ; i < Url.size(); i++) {
url = createUrl(Url.get(i));
try {
//Make http request
String jsonResponse = makeHttpRequest(url);
games = extractFeatureFromJson(jsonResponse);
Total.addAll(games);
} catch (IOException e) {
Log.e("IOException", "" + e);
}
}
return Total;
}
private static URL createUrl(String stringUrl) {
URL url = null;
try {
url = new URL(stringUrl);
} catch (MalformedURLException e) {
Log.e(LOG_TAG, "Error with creating URL ", e);
}
return url;
}
private static String makeHttpRequest(URL url) throws IOException {
String jsonResponse = "";
InputStream inputStream = null;
HttpURLConnection urlConnection = null;
try {
urlConnection = (HttpURLConnection) url.openConnection();
if (urlConnection.getResponseCode() == 200) {
inputStream = urlConnection.getInputStream();
jsonResponse = readInputStream(inputStream);
} else {
Log.e(LOG_TAG, "" + urlConnection.getResponseCode());
return null;
}
} catch (IOException e) {
Log.d(LOG_TAG, "" + e);
} finally {
if (urlConnection != null) {
urlConnection.disconnect();
}
if (inputStream != null) {
// function must handle java.io.IOException here
inputStream.close();
}
}
return jsonResponse;
}
private static String readInputStream(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();
}
private static ArrayList<GameNews> extractFeatureFromJson(String jsonResponse) {
ArrayList<GameNews> games = new ArrayList<>();
try {
JSONObject jsonObject = new JSONObject(jsonResponse);
JSONArray articles = jsonObject.getJSONArray("articles");
for (int i = 0; i < articles.length(); i++) {
JSONObject currentGame = articles.getJSONObject(i);
// Extract the value for the key called "mag"
String title = currentGame.getString("title");
// Extract the value for the key called "place"
String description = currentGame.getString("description");
// Extract the value for the key called "url"
String url = currentGame.getString("url");
//Extract value from key called urlToImage
String urlToImage = "nn";
urlToImage = currentGame.getString("urlToImage");
URL urlOfImage = null;
Bitmap bmp = null;
try {
urlOfImage = new URL(urlToImage);
} catch (MalformedURLException e) {
e.printStackTrace();
}
try {
bmp = BitmapFactory.decodeStream(urlOfImage.openConnection().getInputStream());
} catch (IOException e) {
e.printStackTrace();
}
// Create a new {#link Earthquake} object with the magnitude, location, time,
// and url from the JSON response.
GameNews game = new GameNews(title, description,bmp,url);
// Add the new {#link Earthquake} to the list of earthquakes.
games.add(game);
}
} catch (JSONException e) {
Log.d(LOG_TAG, "" + e);
}
return games;
}
}
Thanks in advance.

UDACITY Sunshine Android app showing multiple data values and multiple refresh options

I am new to android and I was trying to learn android using the UDACITY course on building the sunshine app.
Thanks to a couple of stackoverflow posts I was able fix my app from crashes and then get data from the internet using the API key.
Everything works fine except that the data is duplicated and there are 2 actionbars and hereby 2 refresh buttons.
This was just after I completed lesson 2.
My code for forecastfragment.java class and MainActivity.java class are as follows-:
package com.example.hemant.sunshine.app;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.text.format.Time;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.text.SimpleDateFormat;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Date;
import java.util.List;
/**
* A placeholder fragment containing a simple view.
*/
public class ForecastFragment extends Fragment {
ArrayAdapter<String> mForecastAdapter;
public ForecastFragment() {
}
#Override
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setHasOptionsMenu(true);
}
#Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater){
inflater.inflate(R.menu.forecastfragment,menu);
}
#Override
public boolean onOptionsItemSelected(MenuItem item){
int id=item.getItemId();
if(id==R.id.action_refresh){
FetchWeatherTask weatherTask = new FetchWeatherTask();
weatherTask.execute("47408");
return true;
}
return super.onOptionsItemSelected(item);
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
new FetchWeatherTask().execute("47408");
super.onActivityCreated(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
String[] forecastArray={
"Mon 6/23 - Sunny - 31/17",
"Tue 6/24 - Foggy - 21/8",
"Wed 6/25 - Cloudy - 22/17",
"Thurs 6/26 - Rainy - 18/11",
"Fri 6/27 - Foggy - 21/10",
"Sat 6/28 - TRAPPED IN WEATHERSTATION - 23/18",
"Sun 6/29 - Sunny - 20/7"
};
List<String> weekForecast = new ArrayList<String>
(Arrays.asList(forecastArray));
// Now that we have some dummy forecast data, create an ArrayAdapter.
// The ArrayAdapter will take data from a source (like our dummy
forecast) and
// use it to populate the ListView it's attached to.
// Now that we have some dummy forecast data, create an ArrayAdapter.
// The ArrayAdapter will take data from a source (like our dummy
forecast) and
// use it to populate the ListView it's attached to.
mForecastAdapter =
new ArrayAdapter<String>(
getActivity(), // The current context (this activity)
R.layout.list_item_forecast, // The name of the layout
ID.
R.id.list_item_forecast_textview, // The ID of the
textview to populate.
weekForecast);
View rootView= inflater.inflate(R.layout.fragment_main, container,
false);
ListView listView = (ListView) rootView.findViewById(
R.id.listview_forecast);
listView.setAdapter(mForecastAdapter);
return rootView;
}
public class FetchWeatherTask extends AsyncTask<String, Void, String[]> {
private final String LOG_TAG = FetchWeatherTask.class.getSimpleName();
/* The date/time conversion code is going to be moved outside the
asynctask later,
* so for convenience we're breaking it out into its own method now.
*/
private String getReadableDateString(long time){
// Because the API returns a unix timestamp (measured in seconds),
// it must be converted to milliseconds in order to be converted to
valid date.
Date date = new Date(time * 1000);
impleDateFormat format = new SimpleDateFormat("EEE MMM dd");
return format.format(date).toString();
}
/**
* Prepare the weather high/lows for presentation.
*/
private String formatHighLows(double high, double low) {
// For presentation, assume the user doesn't care about tenths of a degree.
long roundedHigh = Math.round(high);
long roundedLow = Math.round(low);
String highLowStr = roundedHigh + "/" + roundedLow;
return highLowStr;
}
/**
* Take the String representing the complete forecast in JSON Format and
* pull out the data we need to construct the Strings needed for the
wireframes.
+ *
+ * Fortunately parsing is easy: constructor takes the JSON string and converts it
+ * into an Object hierarchy for us.
+ */
private String[] getWeatherDataFromJson(String forecastJsonStr, int
numDays)
throws JSONException
{
// These are the names of the JSON objects that need to be extracted.
final String OWM_LIST = "list";
final String OWM_WEATHER = "weather";
final String OWM_TEMPERATURE = "temp";
final String OWM_MAX = "max";
final String OWM_MIN = "min";
final String OWM_DATETIME = "dt";
final String OWM_DESCRIPTION = "main";
JSONObject forecastJson = new JSONObject(forecastJsonStr);
JSONArray weatherArray = forecastJson.getJSONArray(OWM_LIST);
// OWM returns daily forecasts based upon the local time of the
//city that is being
// asked for, which means that we need to know the GMT offset to
//translate this data
// properly.
// Since this data is also sent in-order and the first day is
//always the
// current day, we're going to take advantage of that to get a nice
// normalized UTC date for all of our weather.
/* Time dayTime = new Time();
dayTime.setToNow();
// we start at the day returned by local time. Otherwise this is a mess.
int julianStartDay = Time.getJulianDay(System.currentTimeMillis(),
dayTime.gmtoff);
// now we work exclusively in UTC
dayTime = new Time();*/
String[] resultStrs = new String[numDays];
for(int i = 0; i < weatherArray.length(); i++) {
// For now, using the format "Day, description, hi/low"
String day;
String description;
String highAndLow;
// Get the JSON object representing the day
JSONObject dayForecast = weatherArray.getJSONObject(i);
// The date/time is returned as a long. We need to convert that
// into something human-readable, since most people won't read
//"1400356800" as
// "this saturday".
long dateTime= dayForecast.getLong(OWM_DATETIME);
day = getReadableDateString(dateTime);
// description is in a child array called "weather", which is 1 element
//long.
JSONObject weatherObject =
dayForecast.getJSONArray(OWM_WEATHER).getJSONObject(0);
description = weatherObject.getString(OWM_DESCRIPTION);
// Temperatures are in a child object called "temp". Try not to name
//variables
// "temp" when working with temperature. It confuses everybody.
JSONObject temperatureObject =
dayForecast.getJSONObject(OWM_TEMPERATURE);
double high = temperatureObject.getDouble(OWM_MAX);
double low = temperatureObject.getDouble(OWM_MIN);
highAndLow = formatHighLows(high, low);
resultStrs[i] = day + " - " + description + " - " + highAndLow;
}
for (String s : resultStrs) {
Log.v(LOG_TAG, "Forecast entry: " + s);
}
return resultStrs;
}
#Override
protected String[] doInBackground(String... params) {
//If there's no zzip code, there's nothing to look up. Verify size of
//params.
if (params.length==0){
return null;
}
// These two need to be declared outside the try/catch
// so that they can be closed in the finally block.
HttpURLConnection urlConnection = null;
BufferedReader reader = null;
// Will contain the raw JSON response as a string.
String forecastJsonStr = null;
String format= "json";
String units= "metric";
int numDays= 7;
try {
// Construct the URL for the OpenWeatherMap query
// Possible parameters are avaiable at OWM's forecast API page, at
// http://openweathermap.org/API#forecast
final String FORECAST_BASE_URL =
"http://api.openweathermap.org/data/2.5/forecast/daily?";
final String QUERY_PARAM = "q";
final String FORMAT_PARAM = "mode";
final String UNITS_PARAM = "units";
final String DAYS_PARAM = "cnt";
final String APPID_PARAM = "appid";
Uri builtUri = Uri.parse(FORECAST_BASE_URL).buildUpon()
.appendQueryParameter(QUERY_PARAM, params[0])
.appendQueryParameter(FORMAT_PARAM, format)
.appendQueryParameter(UNITS_PARAM, units)
.appendQueryParameter(DAYS_PARAM, Integer.toString(numDays))
.appendQueryParameter(APPID_PARAM, BuildConfig.OPEN_WEATHER_MAP_API_KEY)
.build();
URL url = new URL(builtUri.toString());
Log.v(LOG_TAG, "Built URI " + builtUri.toString());
/* String baseUrl =
"http://api.openweathermap.org/data/2.5/forecast/daily?
q=94043&mode=json&units=metric&cnt=7";
String apiKey = "&APPID=" + BuildConfig.OPEN_WEATHER_MAP_API_KEY;
URL url = new URL(baseUrl.concat(apiKey));*/
// 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.
return 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.
return null;
}
forecastJsonStr = buffer.toString();
Log.v(LOG_TAG, "Forecast JSON String:" +forecastJsonStr);
} catch (IOException e) {
Log.e(LOG_TAG, "Error ", e);
// If the code didn't successfully get the weather data, there's
//no point in attemping
// to parse it.
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 {
return getWeatherDataFromJson(forecastJsonStr, numDays);
} catch (JSONException e) {
Log.e(LOG_TAG, e.getMessage(), e);
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(String[] result) {
if (result != null) {
mForecastAdapter.clear();
for(String dayForecastStr : result) {
mForecastAdapter.add(dayForecastStr);
}
// Data has been returned from the server
mForecastAdapter.notifyDataSetChanged();
}
}
}
}
MainActivity.java is as follows-:
package com.example.hemant.sunshine.app;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.ActionBar;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new ForecastFragment())
.commit();
}
}
#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;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}

You are using same fragment via static and dynamic way. That is FrameLayout and fragment in activity_main.xml. You are initiating first fargment in MainActivity via FragmentTransaction as below.
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new ForecastFragment())
.commit();
}
And another fragment is created statically in the content_main.xml
<fragment xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/fragment"
android:name="com.sunshine.ForecastFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
tools:layout="#layout/fragment_main" />
As a result you are initiating 2 fragment and see duplicated data.
To remove one of them will work for you. For example remove FrameLayout in the activity_main.xml:
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="#style/AppTheme.AppBarOverlay">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:popupTheme="#style/AppTheme.PopupOverlay" />
</android.support.design.widget.AppBarLayout>
<include layout="#layout/content_main" />
<android.support.design.widget.FloatingActionButton
android:id="#+id/fab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom|end"
android:layout_margin="#dimen/fab_margin"
android:src="#android:drawable/ic_dialog_email" />
and remove the following part in the MainAcitivty.java:
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new ForecastFragment())
.commit();
}
Why you have 2 refresh button. Because you are using Toolbar item in acitivity_main.xml and AppTheme with DarkActionBar. To use toolbar you must use a theme with No Actionbar.
In the AndroidManifest.xml replace this line.
"android:theme="#style/AppTheme">"
with
android:theme="#style/AppTheme.NoActionBar">
Then go to MainActivity and init your Toolbar as follows
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
if (getSupportActionBar() != null) {
getSupportActionBar().setDisplayShowTitleEnabled(true);
}

UDACITY Sunshine Android App Error - java.io.FileNotFoundException

Im a beginner in Android Development and i have been following the SUNSHINE App. Everything seemed to be going great until today that I ran the App and found an Error: java.io.FileNotFoundException:http://api.openweathermap.org/data/2.5/forecast/daily?q=94043&mode=json&units=metric&cnt=7
I did my research and it appears The Openweathermap api now requires an API key.
As a beginner I do not know how to implement this to my current app so as I can continue with my course. I'm simply STUCK because of this.and I would appreciate any work through/help to overcome this:(THANK YOU)
Here is my ForecastFragment.java:
package com.example.android.sunshine.app;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Date;
import java.util.List;
/**
* A placeholder fragment containing a simple view.
*/
public class ForecastFragment extends Fragment {
private ArrayAdapter<String> mForecastAdapter;
public ForecastFragment() {
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setHasOptionsMenu(true);
}
#Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
inflater.inflate(R.menu.forecastfragment, menu);
}
#Override
public boolean onOptionsItemSelected(MenuItem item){
int id = item.getItemId();
if (id == R.id.action_refresh){
FetchWeatherTask weatherTask = new FetchWeatherTask();
weatherTask.execute("94043");
return true;
}
return super.onOptionsItemSelected(item);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
String[] data = {
"Today - Sunny - 88/63",
"Tommorow-Foggy-70/40",
"weds - Cloudy - 72/63",
"Thurs - Asteroids - 75/65",
"Fri - Heavy Rains - 65/56",
"Sat - HELP TRAPPED IN WEATHERSATION - 60/51",
"Sun - Sunny - 80/68"
};
List<String> weekForecast = new ArrayList<String>(Arrays.asList(data));
mForecastAdapter =
new ArrayAdapter<String>(
getActivity(), R.layout.list_item_forcast,
R.id.list_item_forecast_textview,
weekForecast);
ListView listView = (ListView) rootView.findViewById(
R.id.listView_forecast);
listView.setAdapter(mForecastAdapter);
return rootView;
}
public class FetchWeatherTask extends AsyncTask<String, Void, String[]> {
private final String LOG_TAG = FetchWeatherTask.class.getSimpleName();
private String getReadableDateString(long time){
Date date = new Date(time*1000);
SimpleDateFormat format = new SimpleDateFormat("E,MMM d");
return format.format(date).toString();
}
private String formatHighLows(double high,double low){
long roundedHigh = Math.round(high);
long roundedLow = Math.round(low);
return null;
}
private String[] getWeatherDataFromJson(String forecastJsonStr, int numDays)
throws JSONException{
final String OWM_LIST = "list";
final String OWM_WEATHER = "weather";
final String OWM_TEMPERATURE = "temp";
final String OWM_MAX = "max";
final String OWM_MIN = "min";
final String OWM_DATETIME = "dt";
final String OWM_DESCRIPTION = "main";
JSONObject forecastJson = new JSONObject(forecastJsonStr);
JSONArray weatherArray = forecastJson.getJSONArray(OWM_LIST);
String[] resultStrs = new String[numDays];
for (int i=0; i < weatherArray.length(); i++){
String day;
String description;
String highAndLow;
JSONObject dayForecast = weatherArray.getJSONObject(i);
long dateTime = dayForecast.getLong(OWM_DATETIME);
day = getReadableDateString(dateTime);
JSONObject weatherObject = dayForecast.getJSONArray(OWM_WEATHER).getJSONObject(0);
description = weatherObject.getString(OWM_DESCRIPTION);
JSONObject temperatureObject = dayForecast.getJSONObject(OWM_TEMPERATURE);
double high = temperatureObject.getDouble(OWM_MAX);
double low = temperatureObject.getDouble(OWM_MIN);
highAndLow = formatHighLows(high, low);
resultStrs[i] = day +"-"+description +"-"+ highAndLow;
}
for (String s : resultStrs){
Log.v(LOG_TAG,"Forecast entry"+s);
}
return resultStrs;
}
#Override
protected String[] doInBackground(String... params){
if (params.length == 0){
return null;
}
HttpURLConnection urlConnection = null;
BufferedReader reader = null;
String forecastJsonStr = null;
String format = "json";
String units = "metric";
int numDays = 7;
try {
// Construct the URL for the OpenWeatherMap query
// Possible parameters are avaiable at OWM's forecast API page, at
// http://openweathermap.org/API#forecast
final String FORECAST_BASE_URL =
"http://api.openweathermap.org/data/2.5/forecast/daily?";
final String QUERY_PARAM = "q";
final String FORMAT_PARAM = "mode";
final String UNITS_PARAM = "units";
final String DAYS_PARAM = "cnt";
Uri builtUri = Uri.parse(FORECAST_BASE_URL).buildUpon()
.appendQueryParameter(QUERY_PARAM, params[0])
.appendQueryParameter(FORMAT_PARAM,format)
.appendQueryParameter(UNITS_PARAM, units)
.appendQueryParameter(DAYS_PARAM, Integer.toString(numDays))
.build();
URL url = new URL(builtUri.toString());
Log.v(LOG_TAG,"Built URI" + builtUri.toString());
// 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.
forecastJsonStr = 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.
forecastJsonStr = null;
}
forecastJsonStr = buffer.toString();
} catch (IOException e) {
Log.e(LOG_TAG, "Error ", e);
// If the code didn't successfully get the weather data, there's no point in attemping
// to parse it.
forecastJsonStr = 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 {
return getWeatherDataFromJson(forecastJsonStr, numDays);
} catch (JSONException e){
Log.e(LOG_TAG, e.getMessage(),e);
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(String[] result) {
if (result !=null){
mForecastAdapter.clear();
for (String dayForecastStr : result){
mForecastAdapter.add(dayForecastStr);
}
}
}
}
}

To add the API key you just need to append the parameter to the end of the query:
http://api.openweathermap.org/data/2.5/forecast/daily?q=94043&mode=json&units=metric&cnt=7&appid=[your_api_key]
If you click through the examples on their page, you'll see that they've updated their samples to include an API key: http://openweathermap.org/forecast5

First sign up for an API key here
Then add the API key to the end of the query:
http://api.openweathermap.org/data/2.5/forecast/daily?q=94043&mode=json&units=metric&cnt=7&appid=[your_api_key]

Android: how to restart a method with a button click

I have a button that gets month and year from spinners then calls an Async task, which read json data. That part works fine But if I try and change the month and year then click the button again it does nothing. I have to press back to reload the page to click the button again to get different results.
Here is my code. Can any of you smart folks please help me.
package com.app.simplictyPortal;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.List;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import com.app.simplicityPortal.adapter.InvoiceAdapter;
import android.app.Fragment;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.Spinner;
public class InvoiceFragment extends Fragment {
public InvoiceFragment(){}
Button load;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_invoice, container, false);
ArrayList<String> years = new ArrayList<String>();
int thisYear = Calendar.getInstance().get(Calendar.YEAR);
int currentMonth = Calendar.getInstance().get(Calendar.MONTH);
for (int i = 2013; i <= thisYear; i++)
{
years.add(Integer.toString(i));
}
//String tmonth = Integer.toString(currentMonth);
String tyear = Integer.toString(thisYear);
final Spinner year = (Spinner)rootView.findViewById(R.id.spinner1);
final Spinner month = (Spinner)rootView.findViewById(R.id.spinner2);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(getActivity(),
android.R.layout.simple_spinner_item, years);
// Specify the layout to use when the list of choices appears
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
// Apply the adapter to the spinner
year.setAdapter(adapter);
year.setSelection(adapter.getPosition(tyear));
ArrayAdapter<CharSequence> adapter2 = ArrayAdapter.createFromResource(getActivity(),
R.array.month, android.R.layout.simple_spinner_item);
// Specify the layout to use when the list of choices appears
adapter2.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
// Apply the adapter to the spinner
month.setAdapter(adapter2);
month.setSelection(currentMonth);
load=(Button)rootView.findViewById(R.id.button1);
load.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
String y = (String) year.getSelectedItem();
int im = month.getSelectedItemPosition();
String m = Integer.toString(im +1);
final GlobalClass globalVariable = (GlobalClass) getActivity().getApplicationContext();
final String Compid = globalVariable.getCompid();
new InvoiceAsyncTask().execute("http://dev-sql1:8080/api/invoice/getall/"+Compid+"?m="+m+"&y="+y);
}
});
return rootView;
}
public void invoice(JSONArray jArray) {
ListView lv = (ListView) getView().findViewById(R.id.listView1);
List<ListViewItem> items = new ArrayList<InvoiceFragment.ListViewItem>();
try {
for (int i = 0; i <jArray.length(); i++) {
final JSONObject json_data = jArray.getJSONObject(i);
items.add(new ListViewItem()
{{
Vendor= json_data.optString("CarrierName");
Bill = "$ " + json_data.optString("BillAmount");
Serviceacct = json_data.optString("ServiceAccountNumber");
Date = json_data.optString("ReceivedDate");
}});
}
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
InvoiceAdapter adapter = new InvoiceAdapter(getActivity(), items);
lv.setAdapter(adapter);
// TODO Auto-generated method stub
}
public class ListViewItem
{
public String Vendor;
public String Bill;
public String Serviceacct;
public String Date;
} public static String GET(String url){
InputStream inputStream = null;
String result = "";
try {
// create HttpClient
HttpClient httpclient = new DefaultHttpClient();
// make GET request to the given URL
HttpResponse httpResponse = httpclient.execute(new HttpGet(url));
// receive response as inputStream
inputStream = httpResponse.getEntity().getContent();
// convert inputstream to string
if(inputStream != null)
result = convertInputStreamToString(inputStream);
else
result = "Did not work!";
} catch (Exception e) {
Log.d("InputStream", e.getLocalizedMessage());
}
return result;
}
private static String convertInputStreamToString(InputStream inputStream) throws IOException{
BufferedReader bufferedReader = new BufferedReader( new InputStreamReader(inputStream));
String line = "";
String result = "";
while((line = bufferedReader.readLine()) != null)
result += line;
inputStream.close();
return result;
}
public class InvoiceAsyncTask extends AsyncTask<String, Void, String> {
#Override
protected String doInBackground(String... urls) {
return GET(urls[0]);
}
// onPostExecute displays the results of the AsyncTask.
#Override
protected void onPostExecute(String result) {
try {
JSONArray jArray = new JSONArray(result);
invoice(jArray);
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}

How do you process results of your InvoiceAsyncTask? Do you implement a callback from your AsyncTask's onPostExecute() to the activity?
Maybe the sample below will help you.
First, implement AsyncTask class with callback interface:
public class ServerRequestAsyncTask extends AsyncTask<String, Void, ServerResponseDetails> {
public ServerRequestAsyncTask(Fragment fragment, ServerRequestDetails request) {
mFragment = fragment;
mRequest = request;
}
public interface OnServerRequestAsyncTaskCompletedListener {
void onServerRequestAsyncTaskCompleted(ServerResponseDetails response);
}
public void cancel() {
if (mHttpGet != null && !mHttpGet.isAborted()) mHttpGet.abort();
cancel(true);
}
And also add onPostExecute():
#Override
protected void onPostExecute(ServerResponseDetails response) {
if (mFragment != null) mFragment.onServerRequestAsyncTaskCompleted(response);
}
I call AsyncTask from Fragment, but you can use it with Activity instead.
Then, in your Activity you implement interface:
#Override
public void onServerRequestAsyncTaskCompleted(ServerResponseDetails response) {
// do what you need here, then 'finish' task by setting mServerRequest to null
mServerRequest = null;
}
And to execute AsyncTask:
protected ServerRequestAsyncTask mServerRequest = null;
public boolean isServerRequestRunning() {
return (mServerRequest != null);
}
public void cancelServerRequest() {
mServerRequest.cancel();
}
public void sendServerRequest(Fragment fragment, ServerRequestDetails request) {
if (Application.isNetworkAvailable()) {
if (!isServerRequestRunning()) {
mServerRequest = new ServerRequestAsyncTask(fragment, request);
mServerRequest.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR,
{params});
}
}
}
mServerRequest variable holds reference to currently executed task. You can call mServerRequest.cancel() if need to abort.

Thanks Everyone But I have figured it out. I needed to cancel the Async task in the post execute method.
#Override
protected void onPostExecute(String result) {
try {
JSONArray jArray = new JSONArray(result);
invoice(jArray);
cancel(true);
isCancelled();
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

AsyncTask doesn't call onPostExecute(Result result)

I m trying here to display a 7 day weather forecast from OWM API using AsyncTask.
doInBackground(String...param) method is also working fine. I have checked the LOGCAT.
After the async has finished the execution. I tried to refresh the ListView on refresh button in the menu. But it seems the onPostExecute() does care all about.
ForecastFragment.java
package com.example.sunshine;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Date;
import java.util.List;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ListView;
/**
* A placeholder fragment containing a simple view.
*/
public class ForecastFragment extends Fragment {
private ArrayAdapter<String> mForeCastAdapter;
public String[] forecastArray;
public ForecastFragment() {
}
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setHasOptionsMenu(true);
}
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
inflater.inflate(R.menu.forecastfragment, menu);
}
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.action_refresh) {
new FetchWeatherTask().execute("44700");
return true;
}
return super.onOptionsItemSelected(item);
}
protected void onPostExecute(String[] result) {
if (result != null) {
Log.v("msg", result[0]);
mForeCastAdapter.clear();
// forecastArray = result;
for (String dayForecastStr : result) {
mForeCastAdapter.add(dayForecastStr);
// mForeCastAdapter.notifyDataSetChanged();
}
}
mForeCastAdapter.notifyDataSetChanged();
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState)
{
String[] list = { "1", "2", "3" };
List<String> weekForeCast = new ArrayList<String>(
Arrays.asList(list));
mForeCastAdapter = new ArrayAdapter<String>(getActivity(),
R.layout.list_item_forecast, R.id.list_item_forecast_textview,
weekForeCast);
View rootView = inflater.inflate(R.layout.fragment_main, container,
false);
ListView weekList = (ListView) rootView
.findViewById(R.id.list_item_forecast);
weekList.setAdapter(mForeCastAdapter);
return rootView;
}
}
class FetchWeatherTask extends AsyncTask<String, Void, String[]> {
private final String LOG_TAG = FetchWeatherTask.class.getSimpleName();
protected ArrayAdapter<String> mForeCastAdapter;
/*
* The date/time conversion code is going to be moved outside the asynctask later, so for convenience we're breaking it out into its own method now.
*/
private String getReadableDateString(long time) {
// Because the API returns a unix timestamp (measured in seconds),
// it must be converted to milliseconds in order to be converted to
// valid date.
Date date = new Date(time * 1000);
SimpleDateFormat format = new SimpleDateFormat("E, MMM d");
return format.format(date).toString();
}
/**
* Prepare the weather high/lows for presentation.
*/
private String formatHighLows(double high, double low) {
// For presentation, assume the user doesn't care about tenths of a
// degree.
long roundedHigh = Math.round(high);
long roundedLow = Math.round(low);
String highLowStr = roundedHigh + "/" + roundedLow;
return highLowStr;
}
/**
* Take the String representing the complete forecast in JSON Format and pull out the data we need to construct the Strings needed for the wireframes.
*
* Fortunately parsing is easy: constructor takes the JSON string and converts it into an Object hierarchy for us.
*/
private String[] getWeatherDataFromJson(String forecastJsonStr, int numDays)
throws JSONException {
// These are the names of the JSON objects that need to be extracted.
final String OWM_LIST = "list";
final String OWM_WEATHER = "weather";
final String OWM_TEMPERATURE = "temp";
final String OWM_MAX = "max";
final String OWM_MIN = "min";
final String OWM_DATETIME = "dt";
final String OWM_DESCRIPTION = "main";
JSONObject forecastJson = new JSONObject(forecastJsonStr);
JSONArray weatherArray = forecastJson.getJSONArray(OWM_LIST);
String[] resultStrs = new String[numDays];
for (int i = 0; i < weatherArray.length(); i++) {
// For now, using the format "Day, description, hi/low"
String day;
String description;
String highAndLow;
// Get the JSON object representing the day
JSONObject dayForecast = weatherArray.getJSONObject(i);
// The date/time is returned as a long. We need to convert that
// into something human-readable, since most people won't read
// "1400356800" as
// "this saturday".
long dateTime = dayForecast.getLong(OWM_DATETIME);
day = getReadableDateString(dateTime);
// description is in a child array called "weather", which is 1
// element long.
JSONObject weatherObject = dayForecast.getJSONArray(OWM_WEATHER)
.getJSONObject(0);
description = weatherObject.getString(OWM_DESCRIPTION);
// Temperatures are in a child object called "temp". Try not to name
// variables
// "temp" when working with temperature. It confuses everybody.
JSONObject temperatureObject = dayForecast
.getJSONObject(OWM_TEMPERATURE);
double high = temperatureObject.getDouble(OWM_MAX);
double low = temperatureObject.getDouble(OWM_MIN);
highAndLow = formatHighLows(high, low);
resultStrs[i] = day + " - " + description + " - " + highAndLow;
for (String s : resultStrs)
{
Log.v(LOG_TAG, "Forecast Array : " + s);
}
}
return resultStrs;
}
#Override
protected String[] doInBackground(String... params)
{
// These two need to be declared outside the try/catch
// so that they can be closed in the finally block.
HttpURLConnection urlConnection = null;
BufferedReader reader = null;
// Will contain the raw JSON response as a string.
String forecastJsonStr = null;
String format = "json";
String units = "metric";
int numDays = 7;
try {
// Construct the URL for the OpenWeatherMap query
// Possible parameters are avaiable at OWM's forecast API page, at
// http://openweathermap.org/API#forecast
// URL url = new
// URL("http://api.openweathermap.org/data/2.5/forecast/daily?" +
// "q=94043&mode=json&units=metric&cnt=7");
final String FORECAST_BASE_URL= ="http://api.openweathermap.org/
data/2.5/forecast/daily?";
final String QUERY_PARAM = "q";
final String MODE_PARAM = "mode";
final String UNIT_PARAM = "units";
final String DAYS_PARAM = "cnt";
Uri urlBuild = Uri
.parse(FORECAST_BASE_URL)
.buildUpon()
.appendQueryParameter(QUERY_PARAM, params[0])
.appendQueryParameter(MODE_PARAM, format)
.appendQueryParameter(UNIT_PARAM, units)
.appendQueryParameter(DAYS_PARAM, Integer.toString(numDays))
.build();
URL url = new URL(urlBuild.toString());
//Log.v(LOG_TAG, "Build URL " + urlBuild.toString());
// 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.
return 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.
return null;
}
forecastJsonStr = buffer.toString();
// Log.v(LOG_TAG, "Forecast JSON String" + forecastJsonStr);
}
catch (IOException e) {
Log.e(LOG_TAG, "Error ", e);
// If the code didn't successfully get the weather data, there's no
// point in attemping
// to parse it.
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 {
return getWeatherDataFromJson(forecastJsonStr, numDays);
}catch(JSONException e){
Log.e(LOG_TAG,e.getMessage(), e);
e.printStackTrace();
}
return null;
}
}

Try using the method onPostExecute in your AsyncTask class rather than your Fragment class. The AsyncTask class looks like this:
private class MyTask extends AsyncTask<String, Void, String[]> {
#Override
protected String[] doInBackground(String... params) {
}
#Override
protected void onPostExecute(String result[]) {
}
#Override
protected void onPreExecute() {
}
#Override
protected void onProgressUpdate(Void... values) {
}
}
For your case, you will want to put the onPostExecute method inside your FetchWeatherTask class as such:
class FetchWeatherTask extends AsyncTask<String, Void, String[]> {
....
#Override
protected void onPostExecute(String result[]) {
if (result != null) {
Log.v("msg", result[0]);
mForeCastAdapter.clear();
//forecastArray = result;
for (String dayForecastStr : result) {
mForeCastAdapter.add(dayForecastStr);
//mForeCastAdapter.notifyDataSetChanged();
}
}
mForeCastAdapter.notifyDataSetChanged();
}
....
}

You should be overriding the OnPostExecute() in your FetchWeatherTask the same way you are overriding doInBackground()

The async task doesm't have an onPostExecute() method. You have a method called onPostExecute() in your fragment but not in asynctask.
Note that your IDE didn't auto-complete #Override there. If you added it there yourself, you'd get an error about not overriding a base class method.

First time solved the answer on my own by proper use of LogCat - This is great
The error was causing due to double declaration of public static ArrayAdapter<String> mForeCastAdapter=null.
Solved it using the line numbers given along each error.
P.S: I was searching for answers for about 4 hours before I posted the question. I guess it was for some good reason.