I have a problem with AsyncTask, onPostExecute method runs before doInBackground method finishes its job.
I'm trying to get some data from Firebase database, save it to an array list of "Didattica" objects to be passed to an expandable list view, I have 4 object on the database.
The problem is that onPostExecute runs soon after doInBackground and then doInBackground finishes its job populating the arrayList.
public class DidatticaActivity extends AppCompatActivity {
ArrayList<Didattica> reishiki1 = null;
private ExpandableListView listView1;
private ExpandableListAdapter listAdapter1;
private List<String> listDataHeader1;
private HashMap<String, List<String>> listHash1;
AsyncTaskDidattica atDidattica;
final FirebaseDatabase database = FirebaseDatabase.getInstance();
private DatabaseReference refDidattica1;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_didattica);
listHash1 = new HashMap<>();
listDataHeader1 = new ArrayList<>();
listView1 = findViewById(R.id.lvReishiki);
atDidattica = new AsyncTaskDidattica();
atDidattica.execute();
listAdapter1 = new ExpandableListAdapter(this, listDataHeader1,listHash1);
listView1.setAdapter(listAdapter1);
}
private class AsyncTaskDidattica extends AsyncTask<String, String, HashMap<String, ArrayList<Didattica>>>{
#Override
protected void onPreExecute() {
super.onPreExecute();
}
#Override
protected HashMap<String, ArrayList<Didattica>> doInBackground(String... strings) {
HashMap result = new HashMap<>();
reishiki1 = new ArrayList<>();
try {
refDidattica1 = database.getReference("didattica/1-reishiki");
refDidattica1.addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot1) {
Log.i("shinseiLog", "onDataChange" );
for (DataSnapshot child1 : dataSnapshot1.getChildren()) {
Didattica d1 = child1.getValue(Didattica.class);
reishiki1.add(d1);
}
Log.i("shinseiLog", "rei size1: " + reishiki1.size());
}
#Override
public void onCancelled(DatabaseError databaseError) {}
});
result.put("reishiki", reishiki1);
Log.i("shinseiLog", "map size 1: " + result.size());
return result;
}catch(Exception e){
Log.i("shinseiLog", "eccezione in doInBackground");
}
return null;
}
#Override
protected void onPostExecute(HashMap<String, ArrayList<Didattica>> result) {
super.onPostExecute(result);
ArrayList<Didattica> rei = result.get("reishiki");
Log.i("shinseiLog", "rei size2: " + rei.size());
for(Didattica r: rei){
listDataHeader1.add(r.getTitolo());
listHash1.put(r.getTitolo(),r.getList());
}
Log.i("shinseiLog", "header: " + listDataHeader1.size());
Log.i("shinseiLog", "hash: " + listHash1.size());
listAdapter1.notifyDataSetChanged();
}
}
}
I added some logs to help understand the order:
I/shinseiLog: map size 1: 1
I/shinseiLog: rei size2: 0
I/shinseiLog: header: 0
I/shinseiLog: hash: 0
I/shinseiLog: onDataChange
I/shinseiLog: rei size1: 4
Last row correctly shows that the arrayList contains all my data, but it is too late.
Why is it executing this way? Where am I wrong?
Thanks
Remember that firebase is async.
So your method...
public void onDataChange(DataSnapshot dataSnapshot1) {
}
...is executing in another thread. That's why onPostExecute is executed first.
Try this, put the code from onPostexecute code inside the method onDataChange, see this picture
Firebase is already Asynchronous, you dont need to use an AsyncTask to get or upload data.
Related
I am busy with an application where i am getting data from my azure database with sql and storing it in an array. I created a separate class where i get my data and my main activity connects to this class and then displays it.
Here is my getData class:
public class GetData {
Connection connect;
String ConnectionResult = "";
Boolean isSuccess = false;
public List<Map<String,String>> doInBackground() {
List<Map<String, String>> data = null;
data = new ArrayList<Map<String, String>>();
try {
ConnectionHelper conStr=new ConnectionHelper();
connect =conStr.connectionclass(); // Connect to database
if (connect == null) {
ConnectionResult = "Check Your Internet Access!";
} else {
// Change below query according to your own database.
String query = "select * from cc_rail";
Statement stmt = connect.createStatement();
ResultSet rs = stmt.executeQuery(query);
while (rs.next()) {
Map<String,String> datanum=new HashMap<String,String>();
datanum.put("NAME",rs.getString("RAIL_NAME"));
datanum.put("PRICE",rs.getString("RAIL_UNIT_PRICE"));
datanum.put("RANGE",rs.getString("RAIL_RANGE"));
datanum.put("SUPPLIER",rs.getString("RAIL_SUPPLIER"));
datanum.put("SIZE",rs.getString("RAIL_SIZE"));
data.add(datanum);
}
ConnectionResult = " successful";
isSuccess=true;
connect.close();
}
} catch (Exception ex) {
isSuccess = false;
ConnectionResult = ex.getMessage();
}
return data;
}
}
And in my Fragmentactivity.java I simply just call the class as shown here:
List<Map<String,String>> MyData = null;
GetValence mydata =new GetValence();
MyData= mydata.doInBackground();
String[] fromwhere = { "NAME","PRICE","RANGE","SUPPLIER","SIZE" };
int[] viewswhere = {R.id.Name_txtView , R.id.price_txtView,R.id.Range_txtView,R.id.size_txtView,R.id.supplier_txtView};
ADAhere = new SimpleAdapter(getActivity(), MyData,R.layout.list_valence, fromwhere, viewswhere);
list.setAdapter(ADAhere);
list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
HashMap<String,Object> obj=(HashMap<String,Object>)ADAhere.getItem(position);
String ID=(String)obj.get("A");
Toast.makeText(getActivity(), ID, Toast.LENGTH_SHORT).show();
}
});
My problem comes when I want to include the onPreExecute and onPostExecute because I am relatively new to android studio and I do not know where to put the following lines of code:
#Override
protected void onPreExecute() {
ProgressDialog progress;
progress = ProgressDialog.show(MainActivity.this, "Synchronising", "Listview Loading! Please Wait...", true);
}
#Override
protected void onPostExecute(String msg) {
progress.dismiss();
}
You need to get the data from your azure database using a background service or AsyncTask. However, you are defining a class GetData which does not extend AsyncTask and hence the whole operation is not asynchronous. And I saw you have implemented doInBackground method which is not applicable here as you are not extending AsyncTask. I would suggest an implementation like the following.
You want to get some data from your azure database and want to show them in your application. In these kind of situations, you need to do this using an AsyncTask to call the server api to get the data and pass the data to the calling activity using an interface. Let us have an interface like the following.
public interface HttpResponseListener {
void httpResponseReceiver(String result);
}
Now from your Activity while you want to get the data through an web service call, i.e. AsyncTask, just the pass the interface from the activity class to the AsyncTask. Remember that your AsyncTask should have an instance variable of that listener as well. So the overall implementation should look like the following.
public abstract class HttpRequestAsyncTask extends AsyncTask<Void, Void, String> {
public HttpResponseListener mHttpResponseListener;
private final Context mContext;
HttpRequestAsyncTask(Context mContext, HttpResponseListener listener) {
this.mContext = mContext;
this.mHttpResponseListener = listener;
}
#Override
protected String doInBackground(Void... params) {
String result = null;
try {
// Your implementation of getting data from your server
} catch (Exception e) {
e.printStackTrace();
}
return result;
}
#Override
protected void onPostExecute(final String result) {
mHttpResponseListener.httpResponseReceiver(result);
}
#Override
protected void onCancelled() {
mHttpResponseListener.httpResponseReceiver(null);
}
}
Now you need to have the httpResponseReceiver function implemented in the calling Activity. So the sample activity should look like.
public class YourActivity extends AppCompatActivity implements HttpResponseListener {
// ... Other code and overriden functions
public void callAsyncTaskForGettingData() {
// Pass the listener here
HttpRequestAsyncTask getDataTask = new HttpRequestGetAsyncTask(
YourActivity.this, this);
getDataTask.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
}
#Override
public void httpResponseReceiver(String result) {
// Get the response callback here
// Do your changes in UI elements here.
}
}
To read more about how to use AsyncTask, you might consider having a look at here.
I am relatively new to RxJava/RxAndroid. I have been using AsyncTask to do my long running tasks before now.
I have converted most of my AsyncTask to RxJava but this one.
The particular problem I am having is calling something like AsyncTask's publishProgress(params); in
the background thread. I need to do this to update the progress of a ProgressBar.
First this is the code in AsyncTask
private static class AddBooksToDatabase extends AsyncTask<String, String, String> {
//dependencies removed
AddBooksToDatabase(AddBooksDbParams params) {
//Removed assignment codes
}
#Override
protected String doInBackground(String... strings) {
//Initializing custom SQLiteOpenHelper and SQLite database
File mFile = new File(mFolderPath);
int booksSize = getFilesInFolder(mFile).size();
String[] sizeList = {String.valueOf(booksSize)};
//The first publishProgress is used to set the max of the progressbar
publishProgress(sizeList);
for (int i = 0; i < booksSize; i++) {
//publishProgress with current item, current file
publishProgress(String.valueOf(i), getFilesInFolder(mFile).get(i).getName());
//Inserting current items in database. Code removed
}
return null;
}
#Override
protected void onPreExecute() {
//Show ProgressBar
}
#Override
protected void onPostExecute(String s) {
//Hide ProgressBar
}
#Override
protected void onProgressUpdate(String... values) {
super.onProgressUpdate(values);
if (values.length == 1) {
//The first call to publishProgress
mProgressBar.setMax(Integer.parseInt(values[0]));
} else {
//Subsequent calls to publish progress
Log.i(TAG, "Current item is " + values[0] + " and current file is " + values[1]);
infoText.setText(values[1]);
mProgressBar.setProgress(Integer.parseInt(values[0]), true);
}
}
#Override
protected void onCancelled() {
cancel(true);
}
}
Code Using RxJava
final Observable<String[]> addBooksObserver = Observable.create(new Observable.OnSubscribe<String[]>() {
#Override
public void call(Subscriber<? super String[]> subscriber) {
subscriber.onNext(setAddSubscription());
subscriber.onCompleted();
}
})
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread());
private String[] setAddSubscription() {
S//Initializing custom SQLiteOpenHelper and SQLite database
File mFile = new File(mFolderPath);
int booksSize = getFilesInFolder(mFile).size();
String[] sizeList = {String.valueOf(booksSize)};
//The first publishProgress is used to set the max of the progressbar
addBooksObserver.doOnNext(addReturnParams(String.valueOf(sizeList.length), null, null));
for (int i = 0; i < booksSize; i++) {
EpubReader reader = new EpubReader();
//publishProgress with current item, current file*
addBooksObserver.doOnNext(addReturnParams(String.valueOf(sizeList.length),
String.valueOf(i), getFilesInFolder(mFile).get(i).getName()));
//Inserting current item in database. Code removed
}
return null;
}
private String[] addReturnParams(String totalItems, String currentItem, String currentFile) {
return new String[]{totalItems, currentItem, currentFile};
}
The problem is that lines addBooksObserver.doOnNext(addReturnParams( are displaying this error
doOnNext (rx.functions.Action1) cannot be applied to (java.lang.String[])
I don't know have any idea how to fix this because I thought that since setAddSubscription() and addReturnParams(String totalItems, String currentItem, String currentFile) are returning String array then this shouldn't be a problem. Please can you help me out?
you just have to pass the values to the onNext method of your subscriber, not the doOnNext method of your observable!
you also have to subscribe to the service. try something like this for your obserable:
Observable.create(new Observable.OnSubscribe<String[]>() {
#Override
public void call(Subscriber<? super String[]> subscriber) {
setAddSubscription(subscriber);
subscriber.onCompleted();
}
})
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Subscriber<String[]>() {
#Override
public void onCompleted() {
// handle 'oparation is done'
}
#Override
public void onError(Throwable e) {
}
#Override
public void onNext(String[] values) {
if (values.length == 1) {
//The first call to publishProgress
mProgressBar.setMax(Integer.parseInt(values[0]));
} else {
//Subsequent calls to publish progress
Log.i(TAG, "Current item is " + values[0] + " and current file is " + values[1]);
infoText.setText(values[1]);
mProgressBar.setProgress(Integer.parseInt(values[0]), true);
}
}
});
you also need to modify your private methods a little bit:
private void setAddSubscription(Subscriber<? super String[]> subscriber) {
//Initializing custom SQLiteOpenHelper and SQLite database
File mFile = new File(mFolderPath);
int booksSize = getFilesInFolder(mFile).size();
String[] sizeList = {String.valueOf(booksSize)};
//The first publishProgress is used to set the max of the progressbar
subscriber.onNext(addReturnParams(String.valueOf(sizeList.length), null, null));
for (int i = 0; i < booksSize; i++) {
EpubReader reader = new EpubReader();
//publishProgress with current item, current file*
subscriber.onNext(addReturnParams(String.valueOf(sizeList.length),
String.valueOf(i), getFilesInFolder(mFile).get(i).getName()));
//Inserting current item in database. Code removed
}
}
private String[] addReturnParams(String totalItems, String currentItem, String currentFile) {
return new String[]{totalItems, currentItem, currentFile};
}
You can use Subject to call onNext() manually like this:
Subject<Event> event = Subject.create();
Now call the onNext() for sending event like:
event.onNext("event");
Finally you can return Observable by using this code:
event.toFlowable(BackpressureStrategy.LATEST)
.toObservable();
Your Observer should be like Observable.create(new Observable.OnSubscribe<String>() & in your call method you should loop through the StringArray & pass it to onNext for example:
#Override
public void call(Subscriber<? super String> subscriber) {
for(String val : setAddSubscription()) {
subscriber.onNext(val);
}
subscriber.onCompleted();
}
now onNext shall return you individual items & onCompleted will be called upon the loop is finished.
Edit
myObserver.subscribe(new Subscriber<String>() {
#Override
public void onCompleted() {
// handle completion.
}
#Override
public void onError(Throwable e) {
}
#Override
public void onNext(String value) {
// do whatever with each value passed to onNext
}
});
Observable.create(emitter -> {
for (int i = 0; i < 10; i++) {
int[] ii = {i, i * 2};
emitter.onNext(ii);
}
emitter.onComplete();
}).observeOn(AndroidSchedulers.mainThread()).subscribeOn(Schedulers.io()).subscribe(o -> {
// update progress
int[] i = (int[]) o;
Toast.makeText(SearchActivity.this, "oftad " + i[0] + " - " + i[1], Toast.LENGTH_SHORT).show();
}, t -> {
// on error
Toast.makeText(SearchActivity.this, t.getMessage(), Toast.LENGTH_SHORT).show();
}, () -> {
// progress tamom shod
Toast.makeText(SearchActivity.this, "completed", Toast.LENGTH_SHORT).show();
});
I need to show in a listview a query result to the DB. I'm returning the query 2 values ("cod", "value"). I thought of using a SimpleAdapter to solve the problem, but it did not work.
this is my code:
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.techcharacteristic);
PopulateTechCharacteristicList populateList = new PopulateTechCharacteristicList(
this);
populateList.execute();
SimpleAdapter adapter = new SimpleAdapter(this, list,
R.layout.techcharacteristic_rows,
new String[] {"cod", "value"}, new int[] {
R.id.techCharacteristic, R.id.techCharacteristicName });
setListAdapter(adapter);
}
public class PopulateTechCharacteristicList extends
AsyncTask<Integer, String, Integer> {
ProgressDialog progress;
Context context;
public PopulateTechCharacteristicList(Context context) {
this.context = context;
}
protected void onPreExecute() {
progress = ProgressDialog.show(TechCharacteristicList.this,
getResources().getString(R.string.Wait), getResources()
.getString(R.string.LoadingOperations));
}
protected Integer doInBackground(Integer... paramss) {
ArrayList<TechCharacteristic> arrayTechChar = new ArrayList<TechCharacteristic>();
TechCharacteristicWSQueries techCharWSQueries = new TechCharacteristicWSQueries();
try {
arrayTechChar = techCharWSQueries
.selectTechCharacteristicByAsset("ARCH-0026");
HashMap<String, String> temp = new HashMap<String,
for(TechCharacteristic strAux : arrayTechChar)
{
temp.put("cod", strAux.getTechCharacteristic() + " - " + strAux.getTechCharacteristicName());
temp.put("value", strAux.getTechCharacteristicValue());
list.add(temp);
}
} catch (QueryException e) {
e.printStackTrace();
return 0;
}
return 1;
}
protected void onPostExecute(Integer result) {
if(result == 1)
progress.dismiss();
}
}
On account of being utlizando the same codes ("cod", "value") to include values in the HashMap, my listView is always showing the last item inserted. But in my statement SimpleAdapter'm using hard coded ("cod", "value") and whenever I put any value other than ("cod", "value") in the HashMap, the listView carries empty.
Can anyone help me?
On account of being utlizando the same codes ("cod", "value") to
include values in the HashMap, my listView is always showing the
last item inserted.
As you are creating HashMap object out of for loop, and adding values to that object only in the for loop,hence the previous values get erased and you get only last values.
To solve this you need to create the HashMap object in for loop corresponding to each row.
Try
HashMap<String, String> temp = null;
for(TechCharacteristic strAux : arrayTechChar)
{
temp = new HashMap<String,String>();
temp.put("cod", strAux.getTechCharacteristic() + " - " + strAux.getTechCharacteristicName());
temp.put("value", strAux.getTechCharacteristicValue());
list.add(temp);
}
In the following code I search HighScore class for the best time results ordered by ascending.
So I'm getting list of best results.
What I having a difficulty is to add the name and the school name to of each time result to the list.(please see the attached images)
private class RemoteDataTask extends AsyncTask<Void, Void, Void> {
// Override this method to do custom remote calls
protected Void doInBackground(Void... params) {
// Gets the current list of bestTime in sorted order
ParseQuery query = new ParseQuery("TestsTopRecords");
query.orderByAscending("bestTime");
try {
results = query.find();
} catch (ParseException e) {
}
return null;
}
#Override
protected void onPreExecute() {
HighScoreTable.this.progressDialog = ProgressDialog.show(HighScoreTable.this, "",
"Loading...", true);
super.onPreExecute();
}
#Override
protected void onProgressUpdate(Void... values) {
super.onProgressUpdate(values);
}
#Override
protected void onPostExecute(Void result) {
// Put the list of results into the list view
ArrayAdapter<Double> adapter = new ArrayAdapter<Double>(HighScoreTable.this,R.layout.todo_row);
for (ParseObject object : results) {
adapter.add((Double) object.get("bestTime"));
}
setListAdapter(adapter);
HighScoreTable.this.progressDialog.dismiss();
TextView empty = (TextView) findViewById(android.R.id.empty);
empty.setVisibility(View.VISIBLE);
}
}
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_high_score_table);
TextView empty = (TextView) findViewById(android.R.id.empty);
empty.setVisibility(View.INVISIBLE);
new RemoteDataTask().execute();
registerForContextMenu(getListView());
}
Here's probably the simplest hack to do this.
Use String instead of Double and do this
ArrayAdapter<String> adapter = new ArrayAdapter<String>(HighScoreTable.this,R.layout.todo_row);
for (ParseObject object : results) {
adapter.add((Double) object.get("bestTime") + " " + object.getString("Name") + " " + object.getString("SchoolAndCity"));
}
I have an application that does some long calculations, and I would like to show a progress dialog while this is done. So far I have found that I could do this with threads/handlers, but didn't work, and then I found out about the AsyncTask.
In my application I use maps with markers on it, and I have implemented the onTap function to call a method that I have defined. The method creates a dialog with Yes/No buttons, and I would like to call an AsyncTask if Yes is clicked. My question is how to pass an ArrayList<String> to the AsyncTask (and work with it there), and how to get back a new ArrayList<String> like a result from the AsyncTask?
The code of the method looks like this:
String curloc = current.toString();
String itemdesc = item.mDescription;
ArrayList<String> passing = new ArrayList<String>();
passing.add(itemdesc);
passing.add(curloc);
ArrayList<String> result = new ArrayList<String>();
new calc_stanica().execute(passing,result);
String minim = result.get(0);
int min = Integer.parseInt(minim);
String glons = result.get(1);
String glats = result.get(2);
double glon = Double.parseDouble(glons);
double glat = Double.parseDouble(glats);
GeoPoint g = new GeoPoint(glon, glat);
String korisni_linii = result.get(3);
So, as you see, I would like to send the string array list "passing" to the AsyncTask, and to get the "result" string array list back from it. And the calc_stanica AssycTask class looks like this:
public class calc_stanica extends AsyncTask<ArrayList<String>, Void, ArrayList<String>> {
ProgressDialog dialog;
#Override
protected void onPreExecute() {
dialog = new ProgressDialog(baraj_mapa.this);
dialog.setTitle("Calculating...");
dialog.setMessage("Please wait...");
dialog.setIndeterminate(true);
dialog.show();
}
protected ArrayList<String> doInBackground(ArrayList<String>... passing) {
//Some calculations...
return something; //???
}
protected void onPostExecute(Void unused) {
dialog.dismiss();
}
So my question is how to get the elements of the "passing" array list in the AsyncTask doInBackground method (and use them there), and how to return an array list to use in the main method (the "result" array list)?
Change your method to look like this:
String curloc = current.toString();
String itemdesc = item.mDescription;
ArrayList<String> passing = new ArrayList<String>();
passing.add(itemdesc);
passing.add(curloc);
new calc_stanica().execute(passing); //no need to pass in result list
And change your async task implementation
public class calc_stanica extends AsyncTask<ArrayList<String>, Void, ArrayList<String>> {
ProgressDialog dialog;
#Override
protected void onPreExecute() {
dialog = new ProgressDialog(baraj_mapa.this);
dialog.setTitle("Calculating...");
dialog.setMessage("Please wait...");
dialog.setIndeterminate(true);
dialog.show();
}
protected ArrayList<String> doInBackground(ArrayList<String>... passing) {
ArrayList<String> result = new ArrayList<String>();
ArrayList<String> passed = passing[0]; //get passed arraylist
//Some calculations...
return result; //return result
}
protected void onPostExecute(ArrayList<String> result) {
dialog.dismiss();
String minim = result.get(0);
int min = Integer.parseInt(minim);
String glons = result.get(1);
String glats = result.get(2);
double glon = Double.parseDouble(glons);
double glat = Double.parseDouble(glats);
GeoPoint g = new GeoPoint(glon, glat);
String korisni_linii = result.get(3);
}
UPD:
If you want to have access to the task starting context, the easiest way would be to override onPostExecute in place:
new calc_stanica() {
protected void onPostExecute(ArrayList<String> result) {
// here you have access to the context in which execute was called in first place.
// You'll have to mark all the local variables final though..
}
}.execute(passing);
Why would you pass an ArrayList??
It should be possible to just call execute with the params directly:
String curloc = current.toString();
String itemdesc = item.mDescription;
new calc_stanica().execute(itemdesc, curloc)
That how varrargs work, right?
Making an ArrayList to pass the variable is double work.
I sort of agree with leander on this one.
call:
new calc_stanica().execute(stringList.toArray(new String[stringList.size()]));
task:
public class calc_stanica extends AsyncTask<String, Void, ArrayList<String>> {
#Override
protected ArrayList<String> doInBackground(String... args) {
...
}
#Override
protected void onPostExecute(ArrayList<String> result) {
... //do something with the result list here
}
}
Or you could just make the result list a class parameter and replace the ArrayList with a boolean (success/failure);
public class calc_stanica extends AsyncTask<String, Void, Boolean> {
private List<String> resultList;
#Override
protected boolean doInBackground(String... args) {
...
}
#Override
protected void onPostExecute(boolean success) {
... //if successfull, do something with the result list here
}
}
I dont do it like this. I find it easier to overload the constructor of the asychtask class ..
public class calc_stanica extends AsyncTask>
String String mWhateveryouwantToPass;
public calc_stanica( String whateveryouwantToPass)
{
this.String mWhateveryouwantToPass = String whateveryouwantToPass;
}
/*Now you can use whateveryouwantToPass in the entire asynchTask ... you could pass in a context to your activity and try that too.*/ ... ...
You can receive returning results like that:
AsyncTask class
#Override
protected Boolean doInBackground(Void... params) {
if (host.isEmpty() || dbName.isEmpty() || user.isEmpty() || pass.isEmpty() || port.isEmpty()) {
try {
throw new SQLException("Database credentials missing");
} catch (SQLException e) {
e.printStackTrace();
}
}
try {
Class.forName("org.postgresql.Driver");
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
try {
this.conn = DriverManager.getConnection(this.host + ':' + this.port + '/' + this.dbName, this.user, this.pass);
} catch (SQLException e) {
e.printStackTrace();
}
return true;
}
receiving class:
_store.execute();
boolean result =_store.get();
Hoping it will help.