I am following the tutorials from Tutplus and youtube on Android WeatherApp creation. Please find my code below. I am trying to connect to OpenWeatherMap and get JSON weather data. Here are my problems:
Its not working.
Is this the right way to create the URL for accessing OpenWeatherMap.
When I registered with the OpenWeatherMap, it gave me a KEY. I am not sure what to do with that. I used it in my code, after getting the httpurlconnection from the server for setting "x-api-key". Don't know if its needed or am doing it
when i get the inputstream, the reader is null and the application hangs after that.
Here is the code:
public class WeatherGrabber {
private static final String TAG = "WeatherGrabber";
private static final String CURRENT_WEATHER_URL =
"http://api.openweathermap.org/data/2.5/weather?q=%s&mode=json";
private static BufferedReader reader;
private static final String my_key = "307ec986e69c22c9a24a1bcf9edd21ea";
public static String loadCurrentWeather(Context context, String city) {
String data = null;
try{
URL web_url = new URL(String.format(CURRENT_WEATHER_URL, city) );
HttpURLConnection conn = (HttpURLConnection)
web_url.openConnection();
conn.addRequestProperty("x-api-key", my_key);
reader = new BufferedReader(new
InputStreamReader(conn.getInputStream()));
String inputLine;
StringBuffer json = new StringBuffer();
while((inputLine = reader.readLine() )!= null){
json.append(inputLine).append("\n");
}
data = json.toString();
}catch (IOException e){
e.printStackTrace();
}finally {
try {
if (in != null)
in.close();
}catch (Exception e) {
e.printStackTrace();
}
}
return data;
}// end of loadCurrentWeather() method
}
You can't run network requests directly on the main thread. You need to use AsyncTask class to do this.
Create a class in you activity
private class LoadCurrentWeatherAsync extends AsyncTask<Void, Void, String>{
#Override
protected String doInBackground(Void... params) {
try {
//Call to your function here
return loadCurrentWeather(MainActivity.this, "newyork");
} catch (Exception e){
return e.toString();
}
}
#Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
//Do what ever you what with this output
Log.d("data", s);
}
}
Then call it inside your activity onCreate method
new LoadCurrentWeatherAsync().execute();
Also make sure that you have enabled the internet permissions in AndroidManifest.xml . Inside the manifest tag insert
<uses-permission android:name="android.permission.INTERNET" />
It's ok
They use the api key to track whether request is from free or paid plan.
I suspect that's because you are sending the network request on main thread. Try the above code
Related
I am trying to get a JSON string from a url and save it into SQLite in my android app.
I was trying some tutorials then realize the suggested methods has a void return type. Are there a more simple straight forward way of getting a JSON String and putting it into an arraylist ready to be saved into SQLite?
Below is what I was stuck at a helper class that gets the data from the url
as they said that the main thread OnCreate does not allow a background process like this. Is there a way to change the return type of AsyncTask or is there a more simple way to fetch JSON String with android?
public class FetchData extends AsyncTask<Void, Void, Void> {
#Override
protected void doInBackground(ArrayList<String>... voids) {
try {
URL url = new URL("http://192.168.403.211/api/wordsupdate.php");
HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
InputStream inputStream = httpURLConnection.getInputStream();
BufferedReader bufferedReader = new BufferedReader (new InputStreamReader(inputStream));
String line ="";
while (line != null) {
line = bufferedReader.readLine();
}
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
}
Go with Volley API. Check the code below which demonstrate POST request. Hope you'll get useful information.
public void getAddress(final String uid) {
String url = "Add Url Here"; // Request a string response from the provided URL.
StringRequest stringRequest = new StringRequest(Request.Method.POST, url,
new Response.Listener<String>() {
#Override
public void onResponse(String response) {
JSONArray dataArray;
JSONObject jsonObject;
address_ids = new ArrayList<>();
address_names = new ArrayList<>();
address_line1 = new ArrayList<>();
address_line2 = new ArrayList<>();
address_state = new ArrayList<>();
address_district = new ArrayList<>();
address_taluka = new ArrayList<>();
address_pincode = new ArrayList<>();
address_status = new ArrayList<>();
address_default = new ArrayList<>();
try {
jsonObject = new JSONObject(response);
dataArray = jsonObject.getJSONArray(JSON_ARRAY);
//adding response values to respective array
for (int i = 0; i < dataArray.length(); i++) {
//Creating a json object of the current index
JSONObject obj;
try {
//getting json object from current index
obj = dataArray.getJSONObject(i);
address_ids.add(obj.getString(TAG_ADDRESS_ID));
address_names.add(obj.getString(TAG_ADDRESS_NAME));
address_line1.add(obj.getString(TAG_ADDRESSLINE_FIRST));
address_line2.add(obj.getString(TAG_ADDRESSLINE_SECOND));
address_state.add(obj.getString(TAG_STATE));
address_district.add(obj.getString(TAG_DISTRICT));
address_taluka.add(obj.getString(TAG_TALUKA));
address_pincode.add(obj.getString(TAG_PINCODE));
address_status.add(obj.getString(TAG_ADDRESS_STATUS));
} catch (JSONException e) {
e.printStackTrace();
}
}
} catch (JSONException e) {
e.printStackTrace();
}
//setting up response values to the fragment
//Toast.makeText(getActivity(), "Error:"+response, Toast.LENGTH_LONG).show();
Log.e(TAG, "onResponse: " + response);
address_name.setText("Name : " + address_names.get(0));
address.setText("Address : " + address_line1.get(0) + "," + address_line2.get(0) + "-" + address_pincode.get(0));
taluka.setText("Taluka : " + address_taluka.get(0));
district.setText("District : " + address_district.get(0));
state.setText("State : " + address_state.get(0));
mCircularProgressBar.setIndeterminate(false);
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Toast.makeText(getApplication(), "Taking bit longer", Toast.LENGTH_LONG).show();
}
}) {
#Override
protected Map<String, String> getParams() {
Map<String, String> params = new HashMap<String, String>();
params.put("mk_address_id", address_id);
return params;
}
};
queue.add(stringRequest);
}
Check this link from Android developer, you can find more info their.
In your code change the "extends" from
AsyncTask<Void, Void, Void>
to
AsyncTask<Void, Void, String>
and the doInBackground method to
protected String doInBackground(ArrayList<String>... voids)
and you will get the string back in the onPostExecute method
Yes there is a way to change the return types: Have a look at your extends AsyncTask: It says AsyncTask<Void, Void, Void>.
According to Android Developers, this means <Params, Progress, Result>.
This means that your
ArrayList<String>... voids won't work too, because you have the Params part set to Void but try to get an ArrayList<String>.
So, to solve your problem, change the three Voids to whatever you need it to input and output.
However, to deserialize JSON you should use an external library (or use a 3rd party library for REST calls altogether).
//AsyncTask has onPostExecute which will be called after background execution, where you will get the result in mainthread
class FetchData extends AsyncTask<Void, Void, String> {
#Override
protected String doInBackground(Void... voids) {
try {
URL url = new URL("http://192.168.403.211/api/wordsupdate.php");
HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
InputStream inputStream = httpURLConnection.getInputStream();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
StringBuilder builder = new StringBuilder();
String line;
while ((line = bufferedReader.readLine()) != null) {
builder.append(line);
}
return builder.toString();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(String result) {
//Your result String is here which runs on MAIN THREAD
super.onPostExecute(result);
}
}
Retrofit 2 will help you - easy and simple
Edit : For Async task see the top answer here
What arguments are passed into AsyncTask<arg1, arg2, arg3>?
In your code snippet , you specified AsyncTask params types are Void. Void means , it does't have any return value. As per AsyncTask Syntax,
You have to specify three arguments.
1- InputType- DoInBanckground
2- ProgressType - Publish Progress.
3- OutputType - OnPostExecute.
The three types used by an asynchronous task are the following:
Params, the type of the parameters sent to the task upon execution.
Progress, the type of the progress units published during the background computation.
Result, the type of the result of the background computation.
In your snippet doInBackground method and AsycTask types are mismatching .
For more information : https://developer.android.com/reference/android/os/AsyncTask.html
I am storing the data that I parsed from the JSON that is returned by my API request into the Firebase database.
submitButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String APIURL = "https://api.github.com/users/" + idInput.getText().toString();
String repoURL = "https://api.github.com/users/" + idInput.getText().toString() + "/repos";
new JSONTask().execute(APIURL);
//new JSONTask().execute(repoURL);
String parsedUserID = idInput.getText().toString();
SM.sendDataToProfile(parsedUserID);
viewPager.setCurrentItem(1);
//addUser(parsedUserID);
}
});
When the button is clicked, it calls a new JSONTask (asynctask) on the APIURL.
JSONTask
public class JSONTask extends AsyncTask<String, String, String> {
#Override
// Any non-UI thread process is running in this method. After completion, it sends the result to OnPostExecute
protected String doInBackground(String... params) {
HttpURLConnection connection = null;
BufferedReader reader = null;
try {
// Pass in a String and convert to URL
URL url = new URL(params[0]);
connection = (HttpURLConnection) url.openConnection();
connection.connect();
InputStream stream = connection.getInputStream();
// Reads the data line by line
reader = new BufferedReader(new InputStreamReader(stream));
StringBuffer strBuffer = new StringBuffer();
String line = "";
while ((line = reader.readLine()) != null) {
strBuffer.append(line);
}
// If we are able to get the data do below :
String retreivedJson = strBuffer.toString();
return retreivedJson;
// When we are not able to retreive the Data
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (connection != null) {
// close both connection and the reader
connection.disconnect();
}
try {
if (reader != null) {
reader.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
return null;
}
And it does parsing in another function.
My question is, as you can see on my setOnClickListener, I tried to make two JSONTask on two different URLs because the first URL gives me the information of the user and the second URL (repoURL) gives me the information of the user's repositories. I tried to fetch the repo info of the user and store it into the DB, but it seems like this is a wrong approach.
What is a right way to call two separate AsyncTasks on two different URLs?
EDIT
private void addUserRepo(final String githubID, final String[] repoList) {
DatabaseReference users = databaseReference.child("users");
users.addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
List list = new ArrayList<String>(Arrays.asList(repoList));
databaseReference.child("users").child(githubID).child("Repos").setValue(list);
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
Using data parsed from
public void formatJSONArray(String results){
try {
JSONArray jsonArray = new JSONArray(results);
RepoInfo[] repoList = new RepoInfo[jsonArray.length()];
for(int i = 0; i < jsonArray.length(); i++){
JSONObject jsonObject=jsonArray.getJSONObject(i);
if(jsonObject.optString("name") != null) {
repoList[i].setRepoName(jsonObject.getString("name"));
//repoNameList.add(jsonObject.getString("name"));
}
if(jsonObject.optString("description") != null) {
repoList[i].setDescription(jsonObject.getString("description"));
//descriptionList.add(jsonObject.getString("description"));
}
if(jsonObject.optJSONObject("owner") != null){
JSONObject ownerObject=jsonObject.getJSONObject("owner");
if(ownerObject.optString("login")!=null) {
repoList[i].setOwner(ownerObject.getString("login"));
//userNameList.add(ownerObject.getString("login"));
}
}
}
} catch (JSONException jsonException){
}
}
The response of two different URLs will surely not be similar. So you need different parse methods for them.
One lazy way would be to use two different AsyncTasks subclasses for two different urls.
Another way would be to store a flag inside the asynctask indicating whether it is dealing with user or repo.
public class JSONTask extends AsyncTask <String , String , String> {
boolean fetchingRepo;
#Override
protected String doInBackground (String... params) {
fetchingRepo = params[0].endsWith("/repos");
//other statements
}
Now inside onPostExecute:
if(fetchingRepo){
//parse one way
} else {
//parse another way
}
I'm trying to see how works an Asynctask class in android. In particular i want reveal in real time the status of the class for see when it is running and when it has finished. For do this, i have created a class that extend the main activity and another class that is the asynctaks class.
This is my main class:
public class PhotoManagement extends Activity{
private String numberOfSelectedPhotos;
private Bitmap currentImage;
private String initConfiguration = "http://www.something.com";
private String response;
private ArrayList<String> formatPhotoList = new ArrayList<String>(); //create a list that will contains the available format of the photos downloaded from the server
private ArrayList<String> pricePhotoList = new ArrayList<String>(); //create a list that will contains the available price for each format of the photos
DownloadWebPageTask webPage = new DownloadWebPageTask();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
protected void onResume(){
super.onResume();
webPage.execute(initConfiguration);
if(webPage.getStatus() == AsyncTask.Status.PENDING){
Log.i("STATUS","PENDING");
}
if(webPage.getStatus() == AsyncTask.Status.RUNNING){
Log.i("","RUNNING");
}
if(webPage.getStatus() == AsyncTask.Status.FINISHED){
Log.i("","FINISHED");
}
}
}
As you can see i want only see the passages of the status with a simple log.
And here there is the asynctask class.
private class DownloadWebPageTask extends AsyncTask<String, Void, String> {
#Override
protected String doInBackground(String... urls) {
for (String url : urls) {
DefaultHttpClient client = new DefaultHttpClient(); //create a new http client
HttpGet httpGet = new HttpGet(url); //create a new http request passing a valid url
try {
HttpResponse execute = client.execute(httpGet); //try to execute the http get request
InputStream content = execute.getEntity().getContent(); //prepare the input stream to read the bytes of the request
BufferedReader buffer = new BufferedReader(
new InputStreamReader(content));
String s = "";
while ((s = buffer.readLine()) != null) {
response += s; //until is present a line to read, the response variable store the value of the lines
}
} catch (Exception e) {
Log.i("MyApp", "Download Exception : " + e.toString()); //Print the error if something goes wrong
}
}
return response; //return the response
}
#Override
protected void onPostExecute(String result) {
result = doInBackground(initConfiguration); //take the result from the DownloadWebPageTask class
result = result.replace("null", "");
Log.i("RESULT",""+result);
//find the price and format value from the result using XmlPullParser
try {
XmlPullParserFactory factory = XmlPullParserFactory.newInstance();
factory.setNamespaceAware(true);
XmlPullParser xpp = factory.newPullParser();
xpp.setInput( new StringReader ( result ) );
int attributeNumber = xpp.getAttributeCount();
int eventType = xpp.getEventType();
String currentTag = null;
while(eventType != XmlPullParser.END_DOCUMENT){
if(eventType == XmlPullParser.START_TAG) {
currentTag = xpp.getName();
if (currentTag.equals("product")){
xpp.getAttributeValue(null, "name");
formatPhotoList.add(xpp.getAttributeValue(null, "name"));
Log.i("FORMAT PHOTO",""+xpp.getAttributeValue(null, "name"));
}
}
eventType = xpp.next();
}
} catch (XmlPullParserException e) {
e.printStackTrace();
Log.i("","ERROR XML PULL PARSER");
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
Log.i("","ERROR IOEXCEPTION");
}
}
}
}
As you can see i have implemented also the method onPostExecute that should be called when the asynctask method has finished to execute the instructions right?
So at this point i don't understand why my log RUNNING and my log FINISHED never appear on the log cat.
What i'm doing wrong?
I'm tried to follow this topic Android, AsyncTask, check status? but in my case it isn't working.
Thanks
Problem :
You are creating object like
DownloadWebPageTask webPage = new DownloadWebPageTask();
But you are calling asynctask on different object,
new DownloadWebPageTask().execute(initConfiguration);
Solution :
It should be like
webPage.execute(initConfiguration);
#Override
protected void onResume(){
super.onResume();
new DownloadWebPageTask().execute(initConfiguration);
here do like this
#Override
protected void onResume(){
super.onResume();
webPage.execute(initConfiguration);
You didn't implement webPage.execute(), add it
Most probably the task hasn't finished or even started yet. As you probably know the AsyncTask is doing it's (background) work on a different thread, so your onResume is running in parallel with it. You can either use the task's get() method to wait for it to finish and get the result of the doInBackground() method and then query for it's status or notify your activity from the task's onPostExecute() method to let it know (and log) that it has finished. I don't recommend you the first option because it will actually block the UI thread and will make your usage of AsyncTask pointless.
I'm using AsyncTask and all the examples I found about an AsyncTask is inside an activity.
I'm trying to make an application with a lot of activity and some must download a HTML page. I don't really want to copy-paste the same code all the time in every activity. I find this to be dirty.
So I need to do it as a special class Async HttpGet and pass the function with an argument. I will execute after the doinbackground (different for every activity).
Is this possible or do I need to copy-paste my code in every activity and change the do in background to do what I need after downloading the HTML page?
Here's an AsyncTask that will download data from a url and update the calling activity.
Make sure your calling activity implements the interface DownloadDataTask.DownloadCompleteHandler and that it passes itself as parameter to the DownloadDataTask constructor.
public class DownloadDataTask extends AsyncTask<String, Integer, String> {
public interface DownloadCompleteHandler
{
public void handleDownloadComplete(String result);
}
private DownloadCompleteHandler handler;
private String url;
public DownloadDataTask(DownloadCompleteHandler handler, String url) {
this.handler = handler;
this.url = url;
}
/* AsyncTask methods */
#Override
protected String[] doInBackground(String... empty) {
return downloadData(url);
}
#Override
protected void onPostExecute(String result) {
handler.handleDownloadComplete(result);
}
/* Downloading Data */
private String downloadData(String urlStr) {
InputStream is = null;
String result = new String();
try {
is = getInputStream(urlStr);
BufferedReader in = new BufferedReader(new InputStreamReader(is));
String inputLine;
while ((inputLine = in.readLine()) != null) {
result += inputLine;
} catch (MalformedURLException ex) {
return "Malformed URL: " + ex.getMessage();
} catch (SocketTimeoutException ex) {
return "Connection timed out";
} catch (IOException ex) {
return "IOException: " + ex.getMessage();
}
finally {
if (is != null)
is.close();
}
return result;
}
private InputStream getInputStream(String urlStr) throws IOException
{
URL url = new URL(urlStr);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setReadTimeout(7000);
conn.setConnectTimeout(7000);
conn.setRequestMethod("GET");
conn.setDoInput(true);
conn.connect();
return conn.getInputStream();
}
}
Just create a class that extends AsyncTask that you can reuse.
public abstract class MyAsyncTask extends AsyncTask<Void, Void, String> {
private final String url;
public MyAsyncTask(String url){
this.url = url;
}
#Override
protected String doInBackground(Void... params){
// get data from url.
return null;
}
}
And then to call it, just create an instance of that class.
new MyAsyncTask("http://www.google.com"){
public void onPostExecute(String result){
// update your views.
}
}.execute();
Well what you can do is create an listener for AsyncTask completion, which listens when your AsyncTask is completed and return you the data. I had created an example to execute database queries in background thread and then returning the data to the Activity. Just check it and you can create similar AsyncTask for your problem.
UPDATE:-
Also you can use BroadCastReceiver as a Listener when your AsyncTask is completed and return the value.
Interface is another option for creating a Listener for AsyncTask.
Here is a demo from my github
I'm having a really tough nut to crack with a bug. Api being used is v11, honeycomb 3.0
I have a asynctask inside a fragment downloading from a XML api with basic authentication. It works perfectly even when i change the parameters from the fragment within with the edittexts etc. But when i try to mutate a autocompletetextview from outside the fragment, suddenly i get a "no element at line 1. column 0" exception. I tried the androidhttpclient, fiddled with systemprop(http.keepalive), and completly narrowed it down to this method.
public void setStations(String a, String b){
AutoCompleteTextView fromET = (AutoCompleteTextView ) getView().findViewById(R.id.from);
fromET.setText(a);
AutoCompleteTextView toET = (AutoCompleteTextView) getView().findViewById(R.id.to);
toET.setText(b);
}
When this method executes it botches up my downloadtask somewhere. If i manually edit these textview it works fine.
class LoadDataTask extends AsyncTask<String, Integer, ArrayList<Reisadvies>> {
private Exception ex;
private ProgressDialog pd;
protected void onPreExecute() {
//loadprogressdialog
}
protected ArrayList<Reisadvies> doInBackground(String... params) {
try{
ex = null;
return new APIreader().getRA(params[0], params[1], params[2],params[3],params[4],params[5], params[6]);
}catch (Exception e){
cancel(true);
pd.dismiss();
ex = e;
return null;
}
}
protected void onPostExecute(ArrayList<Reisadvies> ra){
//send list to activity
}
protected void onCancelled() {
super.onCancelled();
showError(ex);
}
}
};
public ArrayList<Reisadvies> getRA(String fromStation, String toStation, String viaStation, String dateTime, String departure, String hslAllowed, String yearCard) throws APIException{
try{
String uri = url(fromStation, toStation, viaStation, dateTime, departure, hslAllowed,yearCard);
URL url = new URL(uri);
HttpURLConnection uc = (HttpURLConnection) url.openConnection();
if (!url.getHost().equals(uc.getURL().getHost())) {
throw new APIException("HotspotForwadingActive");
}
String basicAuth = "Basic " + "username:password"; //base64 encoded
uc.setRequestProperty ("Authorization", basicAuth);
uc.connect();
BufferedReader in = new BufferedReader(new InputStreamReader(uc.getInputStream(), "UTF-8"));
try{
return (ArrayList<Reisadvies>) new XMLParser().parseRP(in);
}finally{
uc.connect();
}
}catch (Exception e){
e.printStackTrace();
throw new APIException(e.getMessage());
}
}
I think there is a problem in doInBackground:
pd.dismiss();
You can do operations on UI element only in UI Thread. It means that you can do this in onPostExecute method, or, if you want, you can use runOnUiThread method:
runOnUiThread(new Runnable() {
public void run() {
pd.dismiss();
}
});
I hope this is helpful...
You are right about that too, but the problem was different. Just found out that it was to urlencoding. Should have figured that out right away but was throw off by the fact that it worked sometimes with a space in it :)