I am having a little bit of trouble getting JSON to load in my project.
I used this getJSON method listed in the answers but it won't work. I figured out that simply the connect() function is throwing a RuntimeException.
Here is my whole class including the getJSON method from another question:
private class GetUnis extends AsyncTask<Void, Void, Void> {
@Override
protected Void doInBackground(Void... params) {
HttpsURLConnection con = null;
try {
URL u = new URL(URL2);
con = (HttpsURLConnection) u.openConnection();
con.connect();
BufferedReader br = new BufferedReader(new InputStreamReader(con.getInputStream()));
StringBuilder sb = new StringBuilder();
String line;
while ((line = br.readLine()) != null) {
sb.append(line + "\n");
}
br.close();
test = sb.toString();
} catch (MalformedURLException ex) {
ex.printStackTrace();
} catch (IOException ex) {
ex.printStackTrace();
} finally {
if (con != null) {
try {
con.disconnect();
} catch (Exception ex) {
ex.printStackTrace();
}
}
}
return null;
}
}
And I am calling it like this: new GetUnis().execute();
Edit: Here is the StackTrace
java.lang.RuntimeException: An error occured while executing doInBackground()
at android.os.AsyncTask$3.done(AsyncTask.java:304)
at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355)
at java.util.concurrent.FutureTask.setException(FutureTask.java:222)
at java.util.concurrent.FutureTask.run(FutureTask.java:242)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:818)
Caused by: java.lang.ClassCastException: com.android.okhttp.internal.http.HttpURLConnectionImpl cannot be cast to javax.net.ssl.HttpsURLConnection
at com.example.lukaskohl.myapplication.SelectUni$GetUnis.doInBackground(SelectUni.java:138)
at com.example.lukaskohl.myapplication.SelectUni$GetUnis.doInBackground(SelectUni.java:131)
at android.os.AsyncTask$2.call(AsyncTask.java:292)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:818)
You can call it from you ui thread you need to do this in a background thread
Basically create an asynctask and move your logic to connect to there
use this code to get the json response as string:
/**
* This method returns the entire result from the HTTP response.
*
* @param url The URL to fetch the HTTP response from.
* @return The contents of the HTTP response.
* @throws IOException Related to network and stream reading
*/
public static String getResponseFromHttpUrl(URL url) throws IOException {
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
try {
InputStream in = urlConnection.getInputStream();
Scanner scanner = new Scanner(in);
scanner.useDelimiter("\\A");
boolean hasInput = scanner.hasNext();
if (hasInput) {
return scanner.next();
} else {
return null;
}
} finally {
urlConnection.disconnect();
}
}
this one is to check internet connection and will help you avoid calling this task when the user is offline
public static boolean isNetworkAvaliable(Context ctx) {
ConnectivityManager connectivityManager = (ConnectivityManager) ctx
.getSystemService(Context.CONNECTIVITY_SERVICE);
return ((connectivityManager
.getNetworkInfo(ConnectivityManager.TYPE_MOBILE) != null && connectivityManager
.getNetworkInfo(ConnectivityManager.TYPE_MOBILE).getState() == NetworkInfo.State.CONNECTED)
|| (connectivityManager
.getNetworkInfo(ConnectivityManager.TYPE_WIFI) != null && connectivityManager
.getNetworkInfo(ConnectivityManager.TYPE_WIFI)
.getState() == NetworkInfo.State.CONNECTED)) ;
}
private class GetUnits extends AsyncTask<URL, Void, String> {
@Override
protected void onPreExecute() {
super.onPreExecute();
}
@Override
protected String doInBackground(URL... params) {
URL Url = params[0];
String searchResults = null;
try {
searchResults =getResponseFromHttpUrl(Url);
} catch (IOException e) {
e.printStackTrace();
}
if(searchResults!=null){
try {
JSONArray unitsArray = new JSONArray(searchResults);
// do something cool with units
//// TODO: 02/08/2017
}catch (Exception e){
e.printStackTrace();
Log.e("Places","error "+e);
}
return searchResults;
}
@Override
protected void onPostExecute(String searchResults) {
}
}