Develop Reference

Android Studio: setOnItemClickListener

I have two AppCompatActivitys, both should have an onItemClickListener, but one of them doesn't do anything on click. I've just added a Toast for test reason, later on it should call a function to delete an item from list (with an ajax request)
What am I doing wrong?
I have made custom list and custom adapter for this - I know, I am new to Android Studio, but the other Activity works fine, and I cant find any differences.
public class ActivityListofProducts extends AppCompatActivity {
ProgressDialog pd;
SharedPreferences preferences;
String userid;
String session;
String list_id = "-1"; // or other values
String appVersion = "";
private ArrayList<listProductItem> myProducts = new ArrayList<listProductItem>();
private ArrayList<listProductItem> groceryFilterProducts = new ArrayList<listProductItem>();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
handleIntent(getIntent());
setContentView(R.layout.activity_list_of_products);
this.setTitle(getString(R.string.grocery_list));
Bundle b = getIntent().getExtras();
SwipeRefreshLayout swipeRefreshLayout = (SwipeRefreshLayout) findViewById(R.id.refreshLayout);
if (b != null)
list_id = b.getString("list_id");
Toast.makeText(this, "List to open " + " " + list_id, Toast.LENGTH_SHORT).show();
preferences =
getSharedPreferences(this.getPackageName(), this.MODE_PRIVATE);
userid = preferences.getString("userid", "");
session = preferences.getString("session", "");
appVersion = preferences.getString("appVersion", "");
getData();
swipeRefreshLayout.setOnRefreshListener(
new SwipeRefreshLayout.OnRefreshListener() {
#Override
public void onRefresh() {
getData();
swipeRefreshLayout.setRefreshing(false);
}
}
);
}
public void getData() {
AsyncTask<String, String, String> Task_GetListofProducts = new Task_GetListofProducts();
Task_GetListofProducts.execute("https://get-some-json.com");
}
public void initListofProducts(String jsonString) {
Log.i("jsonString",jsonString);
try {
JSONObject jsonResponse = new JSONObject(jsonString);
JSONObject jsonListMode = jsonResponse.getJSONObject("list");
String ListName = jsonListMode.optString("name");
this.setTitle(ListName);
JSONArray jsonMainNode = jsonResponse.optJSONArray("data");
for (int i = 0; i < jsonMainNode.length(); i++) {
JSONObject jsonChildNode = jsonMainNode.getJSONObject(i);
int item_amount = jsonChildNode.optInt("item_amount");
int id = jsonChildNode.optInt("id");
String item_name = jsonChildNode.optString("item_name",">Name<");
int done = jsonChildNode.optInt("done", 0);
String timestamp = jsonChildNode.optString("timestamp", "");
String item_scale = jsonChildNode.optString("item_scale", "x");
String img = jsonChildNode.optString("img", "x");
double bestprice = jsonChildNode.optDouble("bestprice");
//int oitems = jsonChildNode.optInt("oitems", 0);
//int shared = jsonChildNode.optInt("shared", 0);
String outPut = "item_amount:"+ item_amount +" id:"+ id +" item_name:"+ item_name +" done:"+ done +" timestamp:"+ timestamp +" item_scale:"+ item_scale +" img:"+ img;
Log.i("outPut",outPut);
myProducts.add(new listProductItem(id, item_name, item_amount, item_scale, img, done, timestamp, bestprice));
}
final ListView lv = findViewById(R.id.grocery_list_of_products);
lv.setAdapter(new listofProductsAdapter(this, myProducts));
lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> a, View v, int position, long id) {
/*
!! HERE is my problem. This Code seems not to be executed !!
*/
Toast.makeText(ActivityListofProducts.this, "Should handle click now.", Toast.LENGTH_SHORT).show();
}
});
} catch (JSONException e) {
Toast.makeText(getApplicationContext(), "Error" + e.toString(), Toast.LENGTH_SHORT).show();
}
}
public void setProductDone(int pid, int done) {
String url = "put-some-json.com";
new ActivityListofProducts.Task_SetProductDone().execute(url);
}
private class Task_SetProductDone extends AsyncTask<String, String, String> {
protected void onPreExecute() {
super.onPreExecute();
pd = new ProgressDialog(ActivityListofProducts.this);
pd.setMessage("Please wait");
pd.setCancelable(false);
pd.show();
}
protected String doInBackground(String... params) {
HttpURLConnection connection = null;
BufferedReader reader = null;
Log.i("doInBackground",params.toString());
try {
URL url = new URL(params[0]);
connection = (HttpURLConnection) url.openConnection();
connection.connect();
InputStream stream = connection.getInputStream();
reader = new BufferedReader(new InputStreamReader(stream));
StringBuffer buffer = new StringBuffer();
String line = "";
while ((line = reader.readLine()) != null) {
buffer.append(line + "\n");
Log.d("Response: ", "> " + line); //here you will get whole response...... :-)
}
return buffer.toString();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (UnknownHostException e) {
Toast.makeText(ActivityListofProducts.this, "No Internet?", Toast.LENGTH_SHORT).show();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (connection != null) {
connection.disconnect();
}
try {
if (reader != null) {
reader.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
return null;
}
#Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
if (pd.isShowing()) {
pd.dismiss();
}
Log.i("onPostExecute", result);
}
}
private class Task_GetListofProducts extends AsyncTask<String, String, String> {
protected void onPreExecute() {
super.onPreExecute();
pd = new ProgressDialog(ActivityListofProducts.this);
pd.setMessage("Please wait");
pd.setCancelable(false);
pd.show();
myProducts = new ArrayList<listProductItem>(); //empty list
}
protected String doInBackground(String... params) {
HttpURLConnection connection = null;
BufferedReader reader = null;
Log.i("doInBackground",params.toString());
try {
URL url = new URL(params[0]);
connection = (HttpURLConnection) url.openConnection();
connection.connect();
InputStream stream = connection.getInputStream();
reader = new BufferedReader(new InputStreamReader(stream));
StringBuffer buffer = new StringBuffer();
String line = "";
while ((line = reader.readLine()) != null) {
buffer.append(line + "\n");
Log.d("Response: ", "> " + line); //here you will get whole response...... :-)
}
return buffer.toString();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (connection != null) {
connection.disconnect();
}
try {
if (reader != null) {
reader.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
return null;
}
#Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
if (pd.isShowing()) {
pd.dismiss();
}
initListofProducts(result);
}
}
private class Task_FindProducts extends AsyncTask<String, String, String> {
protected void onPreExecute() {
super.onPreExecute();
pd = new ProgressDialog(ActivityListofProducts.this);
pd.setMessage("Please wait");
pd.setCancelable(false);
pd.show();
myProducts = new ArrayList<listProductItem>(); //empty list
}
protected String doInBackground(String... params) {
HttpURLConnection connection = null;
BufferedReader reader = null;
Log.i("doInBackground",params.toString());
try {
URL url = new URL(params[0]);
connection = (HttpURLConnection) url.openConnection();
connection.connect();
InputStream stream = connection.getInputStream();
reader = new BufferedReader(new InputStreamReader(stream));
StringBuffer buffer = new StringBuffer();
String line = "";
while ((line = reader.readLine()) != null) {
buffer.append(line + "\n");
Log.d("Response: ", "> " + line); //here you will get whole response...... :-)
}
return buffer.toString();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (connection != null) {
connection.disconnect();
}
try {
if (reader != null) {
reader.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
return null;
}
#Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
if (pd.isShowing()) {
pd.dismiss();
}
setFilterProducts(result);
}
}
}

Android - Call Thread synchronized on UI thread

I try to create synchronized threads, but I always get the following error: android.os.NetworkOnMainThreadException.
I've read more posts, but they don't work for me.
Below I write the code blocks that do not work for me:
1.
final SyncApp syncJob = new SyncApp();
Thread t = new Thread (new Runnable () {
                         #Override
                         public void run () {
                             synchronized (syncJob) {
                                 String s = syncJob.insert (newJobs, GlobalVariables.URL_LOCALHOST + "jobs");
                                 txtState.setText (s);
                             }}});
                         }
                     });
                     t.Start ();
// t.run ();
2.
myClass.runOnUiThread(new Runnable() {
public void run() {...}
})
3.
Running code in main thread from another thread
SyncApp:
public class SyncApp {
synchronized public String insert(List<Jobs> job, String... params) {
URL url = null;
HttpURLConnection conn = null;
try {
url = new URL(params[0]);
conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("POST");
conn.setRequestProperty("Content-Type", "application/json");
conn.setDoInput(true);
conn.setDoOutput(true);
String str = new Gson().toJson(job);
byte[] outputInBytes = str.getBytes();
OutputStream os = conn.getOutputStream();
os.write( outputInBytes );
os.flush();
int responseCode=conn.getResponseCode();
String response = null;
if (responseCode == HttpsURLConnection.HTTP_OK) {
String line;
BufferedReader br=new BufferedReader(new InputStreamReader(conn.getInputStream()));
while ((line=br.readLine()) != null) {
response+=line;
}
}
else {
response=conn.getResponseMessage();
}
return response;
} catch (Exception e) {
e.printStackTrace();
} finally {
conn.disconnect();
}
return null;
}
}
I need to call a thread, wait for the answer and call another thread. Their answers I must use them in the activity

I need to call a thread, wait for the answer and call another thread.
Their answers I must use them in the activity
Example using async tasks to accomplish objective.
In this code, let A be your activity which needs to call a thread,
wait for the answer and call another thread. Customize as needed.
Since you never wait in UI threads, callbacks are used to accomplish synchronization.
Let A be your activity class:
public class A extends Activity {
// some method in activity where you launch a background thread (B)
// which then completes and invokes callback which then creates and launches
// a background thread (C) which then completes and invokes a callback.
//
// In callback C, you are on the UI thread.
protected void someMethod() {
new B(new B.CallbackB() {
public void result(Object o) {
new C(new C.CallbackC() {
public void result(Object o, Object answerFromB) {
// OK - C is now done and we are on UI thread!
// 'o' is answer from C
// 'answerFromB' also provided
}
}, o).execute(new Object());
}
).execute(new Object());
}
}
Define a class B:
public class B extends AsyncTask<Object, Void, Object> {
public static interface CallbackB {
void result(Object o);
}
private CallbackB cb;
public B (CallbackB cb) {
this.cb = cb;
}
protected Object doInBackground(Object... params) {
// do work and return an answer.
return new Object();
}
protected void onPostExecute(Object result) {
if (cb != null) {
cb.result(result);
}
}
}
Define a class C:
public class C extends AsyncTask<Object, Void, Object> {
public static interface CallbackC {
void result(Object o, Object answerFromB);
}
private CallbackC cb;
private Object answerFromB;
public C (CallbackC cb, Object answerFromB) {
this.cb = cb;
this.answerFromB = answerFromB;
}
protected Object doInBackground(Object... params) {
// do work and return an answer.
return new Object();
}
protected void onPostExecute(Object result) {
if (cb != null) {
cb.result(result, answerFromB);
}
}
}
For reference:
https://stackoverflow.com/a/9963705/2711811

My solution is:
public class Sync extends AppCompatActivity {
...
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_sync_server);
dao = new DAO(this);
txtState = findViewById(R.id.txt_log);
btnSincro = findViewById(R.id.btn_sincro);
btnSincro.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
countCall = 0;
callFlow();
}
});
btnHome = findViewById(R.id.btn_home);
btnHome.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(SyncServerActivity.this, MainActivity.class);
startActivity(intent);
}
});
}
private void callFlow() {
switch (countCall) {
case 0:
templates = toTemplate("url");
break;
case 1:
jobs = toJobs("url");
break;
case 2:
job = ... //select item
res = sendJobs(jobs, "url");
break;
default:
runOnUiThread(new Runnable() {
#Override
public void run() {
btnSincro.setEnabled(true);
txtState.append("\n\nEND");
}
});
}
}
private void nextStep() {
setText(txtState, "\nSync \n" + countCall + "/3");
countCall++;
callFlow();
}
private void setText(final TextView text, final String value) {
runOnUiThread(new Runnable() {
#Override
public void run() {
text.setText(value);
}
});
}
public List<Templates> toTemplate(final String... params) {
final List<Templates> list = new ArrayList<>();
Thread t = new Thread(new Runnable() {
#Override
public void run() {
URL url = null;
BufferedReader reader = null;
HttpURLConnection connection = null;
try {
url = new URL(params[0]);
connection = (HttpURLConnection) url.openConnection();
connection.connect();
InputStream stream = connection.getInputStream();
reader = new BufferedReader(new InputStreamReader(stream));
int responseCode = connection.getResponseCode();
String response = null;
if (responseCode == HttpsURLConnection.HTTP_OK) {
StringBuffer buffer = new StringBuffer();
String line = "";
while ((line = reader.readLine()) != null) {
buffer.append(line);
}
String finalJson = buffer.toString();
JSONObject parentObject = new JSONObject(finalJson);
JSONArray parentArray = parentObject.getJSONArray("data");
for (int i = 0; i < parentArray.length(); i++) {
Templates item = new Gson().fromJson(parentArray.get(i).toString(), Templates.class);
list.add(item);
}
} else {
response = connection.getResponseMessage();
}
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
} finally {
if (connection != null)
connection.disconnect();
try {
if (reader != null)
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
nextStep(); //call next Thread
}
}
});
t.start();
return list;
}
public List<Jobs> toJobs(final String... params) {
final List<Jobs> list = new ArrayList<>();
Thread t = new Thread(new Runnable() {
#Override
public void run() {
URL url = null;
BufferedReader reader = null;
HttpURLConnection connection = null;
try {
url = new URL(params[0]);
connection = (HttpURLConnection) url.openConnection();
connection.connect();
InputStream stream = connection.getInputStream();
reader = new BufferedReader(new InputStreamReader(stream));
int responseCode = connection.getResponseCode();
String response = null;
if (responseCode == HttpsURLConnection.HTTP_OK) {
StringBuffer buffer = new StringBuffer();
String line = "";
while ((line = reader.readLine()) != null) {
buffer.append(line);
}
String finalJson = buffer.toString();
JSONObject parentObject = new JSONObject(finalJson);
JSONArray parentArray = parentObject.getJSONArray("data");
for (int i = 0; i < parentArray.length(); i++) {
Jobs item = new Gson().fromJson(parentArray.get(i).toString(), Jobs.class);
list.add(item);
}
} else {
response = connection.getResponseMessage();
}
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
} finally {
if (connection != null)
connection.disconnect();
try {
if (reader != null)
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
nextStep();
}
}
});
t.start();
return list;
}
public Boolean sendJobs(final List<Jobs> job, final String... params) {
final Boolean[] result = {false};
Thread t = new Thread(new Runnable() {
#Override
public void run() {
URL url = null;
HttpURLConnection conn = null;
try {
url = new URL(params[0]);
conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("POST");
conn.setRequestProperty("Content-Type", "application/json");
conn.setDoInput(true);
conn.setDoOutput(true);
String str = new Gson().toJson(job);
Log.d(TAG, str);
byte[] outputInBytes = str.getBytes();
OutputStream os = conn.getOutputStream();
os.write(outputInBytes);
os.flush();
int responseCode = conn.getResponseCode();
String response = null;
if (responseCode == HttpsURLConnection.HTTP_OK) {
String line;
BufferedReader br = new BufferedReader(new InputStreamReader(conn.getInputStream()));
while ((line = br.readLine()) != null) {
response += line;
}
result[0] = true;
} else {
response = conn.getResponseMessage();
}
} catch (Exception e) {
e.printStackTrace();
} finally {
conn.disconnect();
nextStep();
}
}
});
t.start();
return result[0];
}
}
Whenever a thread ends, it calls the nextStep() method, which starts the next trhead.

How to avoid force close application in Android

I've tried searching the internet for solution unfortunately I could not find the answer. I tried using try catch to catch error exception but still it won't work.
Here's my code. I have private class LoginTask
private class LoginTask extends AsyncTask<String,String,JSONObject> {
private String[] privateCredentials;
private String privateRequest;
private String errorMessage = "";
//initialize all here
//constructor
LoginTask(String[] credentials,String request) {
this.privateRequest = request;
this.privateCredentials = credentials;
}
#Override
protected void onPostExecute(JSONObject result) {
super.onPostExecute(result);
if(this.privateRequest=="login"){
try {
String response = result.getString("status");
if(response.equals("ok")){
onLoginSuccess(result.getString("username"),result.getString("full_name"),result.getInt("user_id"));
}else{
onLoginFails();
}
} catch (JSONException e) {
if(errorMessage!=""){
Toast ts;
ts = Toast.makeText(LoginActivity.this,errorMessage,Toast.LENGTH_LONG);
ts.show();
}
//e.printStackTrace();
}
}
}
#Override
protected JSONObject doInBackground(String... params) {
String result = "";
JSONObject resultObj = null;
HttpURLConnection con = null;
BufferedReader br = null;
JSONObject cred = new JSONObject();
if(this.privateRequest=="login"){
try {
cred.put("username", this.privateCredentials[0]);
cred.put("password", this.privateCredentials[1]);
URL url = new URL(params[0]);
con = (HttpURLConnection) url.openConnection();
;
con.setDoOutput(true);
con.setDoInput(true);
con.setRequestProperty("Content-Type", "application/json");
con.setRequestProperty("Accept", "application/json");
con.setRequestMethod("POST");
con.connect();
OutputStream outputStream = con.getOutputStream();
outputStream.write(cred.toString().getBytes());
InputStream stream = con.getInputStream();
br = new BufferedReader(new InputStreamReader(stream));
StringBuffer buffer = new StringBuffer();
String line = "";
while ((line = br.readLine()) != null) {
buffer.append(line);
}
//get the result
JSONObject jsonObj = new JSONObject(buffer.toString());
resultObj = jsonObj;
// return buffer.toString();
}catch (JSONException e) {
errorMessage = e.getMessage();
final String error = e.getMessage();
//e.printStackTrace();
runOnUiThread(new Runnable(){
public void run() {
//ErrorDialog(e.getMessage());
Toast ts;
ts = Toast.makeText(LoginActivity.this,error,Toast.LENGTH_LONG);
ts.show();
}
});
} catch (ProtocolException e) {
errorMessage = e.getMessage();
final String error = e.getMessage();
//e.printStackTrace();
runOnUiThread(new Runnable(){
public void run() {
//ErrorDialog(e.getMessage());
Toast ts;
ts = Toast.makeText(LoginActivity.this,error,Toast.LENGTH_LONG);
ts.show();
}
});
//e.printStackTrace();
} catch (IOException e) {
errorMessage = e.getMessage();
final String error = e.getMessage();
//e.printStackTrace();
runOnUiThread(new Runnable(){
public void run() {
//ErrorDialog(e.getMessage());
Toast ts;
ts = Toast.makeText(LoginActivity.this,error,Toast.LENGTH_LONG);
ts.show();
}
});
//e.printStackTrace();
} finally {
if(con!=null) {
con.disconnect();
}
}
return resultObj;
}
return null;
}
}
And here's my event listener code in the login activity.
//when clicking the login button
loginBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
//do now the login process
userText.setVisibility(view.INVISIBLE);
passwordText.setVisibility(view.INVISIBLE);
tvRegister.setVisibility(view.INVISIBLE);
umlogo.setVisibility(view.INVISIBLE);
//set textviews to invisible
/* tv[0].setVisibility(view.INVISIBLE);
tv[1].setVisibility(view.INVISIBLE);*/
//set also the button to invisible
loginBtn.setVisibility(view.INVISIBLE);
//set visible the progress bar
pb.setVisibility(view.VISIBLE);
//set now the user login credentials
credentials[0] = userText.getText().toString();
credentials[1] = passwordText.getText().toString();
loginTask = new LoginTask(credentials,"login");
//loginTask.execute("http://10.0.2.2/sampleRequest.php");
//loginTask.execute("http://10.0.2.2/motorpool_june_2016_laravel/public/mobile/login");
loginTask.execute("http://128.199.105.49/mobile/login");
//SessionHolder.login(credentials, la);
}
});
However it is still not working. Please help. :(

You can't compare Strings with == in java. You must write it like below:
if(this.privateRequest.equals("login")){
== tests for reference equality (whether they are the same object)

i have API key but when i put it in my android studio to return me list its return me but nothing and i can sad that its return me json

public class GetPlaceSearchTask extends AsyncTask<String , Void ,String>
{
private Context context;
private ProgressDialog dialog;
public static final String SEND_RESULT_SEARCH_BROADCAST_FROM_TASK = "send_result_search";
private String API_LOCATION = "https://maps.googleapis.com/maps/api/place/nearbysearch/" +
"json?location=-33.8670522,151.1957362&radius=500&type=restaurant&name=cruise&key=";
public GetPlaceSearchTask(Context context) {
this.context = context;
}
protected void onPreExecute() {
if (context != null) {
dialog = new ProgressDialog(context);
dialog.setTitle("Downloading");
dialog.show();
}
}
#Override
protected String doInBackground(String... params) {
HttpsURLConnection connection = null;
BufferedReader reader = null;
StringBuilder builder = new StringBuilder();
try {
URL url = new URL(String.format(API_LOCATION, params[0], params[1]));
connection = (HttpsURLConnection) url.openConnection();
if (connection.getResponseCode() != HttpsURLConnection.HTTP_OK) {
return null;
}
reader = new BufferedReader(new InputStreamReader(connection.getInputStream()));
String line;
while ((line = reader.readLine()) != null) {
builder.append(line);
}
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
if (connection != null) {
connection.disconnect();
}
if (reader != null) {
try {
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return builder.toString();
}
#Override
protected void onPostExecute(String result) {
if (dialog != null) {
dialog.dismiss();
}
Intent intent = new Intent(SEND_RESULT_SEARCH_BROADCAST_FROM_TASK);
intent.putExtra("result_search", result);
LocalBroadcastManager.getInstance(context).sendBroadcast(intent);
}
public static class GetPlaceSearchTextTask extends AsyncTask<String , Void , String>{
private String API_TEXT = "https://maps.googleapis.com/maps/api/place/textsearch/" +
"json?query=%1$s&location=[%2$s,%3$s]&radius=5000&key=";
public static final String SEND_BROADCAST_RESULT_TEXT_FROM_TASK = "sand_text_result";
private Context context;
private ProgressDialog dialog ;
public GetPlaceSearchTextTask(Context context){
this.context = context;
}
#Override
protected void onPreExecute() {
if (context != null) {
dialog = new ProgressDialog(context);
dialog.setTitle("Downloading");
dialog.show();
}
}
#Override
protected String doInBackground(String... params) {
HttpsURLConnection connection = null;
BufferedReader reader = null;
StringBuilder builder = new StringBuilder() ;
try {
URL url = new URL(API_TEXT + params[0] + params[1] + params[2]) ;
connection = (HttpsURLConnection) url.openConnection();
if (connection.getResponseCode() != HttpsURLConnection.HTTP_OK){
return null;
}
reader = new BufferedReader(new InputStreamReader(connection.getInputStream())) ;
String line;
while ((line=reader.readLine())!= null){
builder.append(line);
}`enter code here`
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
if (connection!=null)
connection.disconnect();
if (reader!=null)
try {
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
return builder.toString();
}
#Override
protected void onPostExecute(String result_text) {
if (dialog!=null){
dialog.dismiss();
}`enter code here`
Intent intent = new Intent(SEND_BROADCAST_RESULT_TEXT_FROM_TASK);
intent.putExtra("text" , result_text);
LocalBroadcastManager.getInstance(context).sendBroadcast(intent);
}
}
}

Android How to wait for an AsyncTask to finish

I have an AsyncTask which acts as a client and get a string from a server and puts it in a String. After the task I use the response from the server but the data haven't changed yet - it's null.
connectBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
...
Client myClient = new Client(responseTV);
myClient.execute();
if (responseStr.charAt(0) == '1') { <----- responseStr is null
changeBrightness(Integer.parseInt(responseStr.substring(1)));
}
}
});
I assume the code keeps going after .execute() which is not very good in my situation.
Update: Added code for Client class.
public class Client extends AsyncTask<Void, Void, Void> {
String response = "";
TextView responseTV;
public Client(TextView responseTV) {
this.responseTV = responseTV;
}
#Override
protected Void doInBackground(Void... params) {
Socket socket = null;
try {
socket = new Socket(IP, PORT);
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream(BUFFER_SIZE);
byte[] buffer = new byte[BUFFER_SIZE];
int bytesRead;
InputStream inputStream = socket.getInputStream();
while ((bytesRead = inputStream.read(buffer)) != -1) {
byteArrayOutputStream.write(buffer, 0, bytesRead);
response += byteArrayOutputStream.toString("UTF-8");
}
} catch (UnknownHostException e) {
e.printStackTrace();
response = "UnknownHostException: " + e.toString();
} catch (IOException e) {
e.printStackTrace();
response = "IOException: " + e.toString();
} finally {
if (socket != null) {
try {
socket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return null;
}
#Override
protected void onPostExecute(Void aVoid) {
//Toast.makeText(MainActivity.this, response, Toast.LENGTH_LONG).show();
responseTV.setText(response);
responseStr = response;
super.onPostExecute(aVoid);
}
}

if (responseStr.charAt(0) == '1') { <----- responseStr is null
changeBrightness(Integer.parseInt(responseStr.substring(1)));
}
Use this code in onPostExecute() method of AsyncTask. It runs on the UI thread and is exactly the method you need after finishing work in doInBackground().