Develop Reference

Asynctask return null in SDK 23 and below device

I'm using Asynctask to pass the parameters of API. The Asynctask executing but the String Response in Asynctask PostExecute giving me a null for a device with SDK 23 and below. But when the device is equal or higher to SDK24(Nougat), it works perfectly and the data are being sent to the API however when the SDK is 23 and lower data are not being sent to API. Does anyone encounter this problem? Please enlighten me what I miss in my code or I do wrong code. Massive thank you.
private class sendToServerOfficial extends AsyncTask<String,Void,String> {
int statusCodeone;
String convert_txt_et_username = et_username.getText().toString();
String convert_txt_content = et_content.getText().toString();
#Override
protected String doInBackground(String... strings) {
try {
urlURL = new URL("http://www.testingsite.com/api/sendServer?/ip="+getIPAddress+"&phone_num="+getMobilePhoneNumber+"&user_text="+convert_txt_et_username+"&content_text="+convert_txt_content);
HttpURLConnection httpURLConnection = (HttpURLConnection) urlURL.openConnection();
httpURLConnection.setRequestMethod("POST");
httpURLConnection.setRequestProperty("Content-Type","UTF-8");
httpURLConnection.connect();
statusCodeone = httpURLConnection.getResponseCode();
if (statusCodeone == 200) {
InputStream it = new BufferedInputStream(httpURLConnection.getInputStream());
InputStreamReader read = new InputStreamReader(it);
BufferedReader buff = new BufferedReader(read);
StringBuilder dta = new StringBuilder();
String chunks;
while ((chunks = buff.readLine()) != null) {
dta.append(chunks);
}
buff.close();
read.close();
return dta.toString();
}
}
catch (ProtocolException e) { e.printStackTrace(); }
catch (MalformedURLException e) { e.printStackTrace(); }
catch (IOException e) { e.printStackTrace(); }
return null;
}
#Override
protected void onPostExecute(String response) {
Toast.makeText(MainActivity.this, response + "Form is submitted already" + urlURL, Toast.LENGTH_LONG).show();
txt_inputURL.setEnabled(true);
btnClick.setClickable(true);
txt_inputURL.getText().clear();
}
}

How to Handle connection timeout in async task

I have a problem that I haven't solved yet and I need help.
When internet is slow application crashes. how can can I check connection timeout in asyntask.
I made an app that sometimes connect to web service to get data and i do that using async task
I want to make alert dialog on connection timeout when user can choose whether they want to retry or cancel, if they choose retry it will try to connect again
public class login extends AsyncTask<Void,Void,Void> {
InputStream ins;
String status, result, s = null, data = "",js;
int ss;
int responseCode;
#Override
protected void onPreExecute() {
super.onPreExecute();
pdlg.setTitle("Checking");
pdlg.setMessage("Please wait");
pdlg.setCancelable(false);
pdlg.show();
}
#Override
protected Void doInBackground(Void... params) {
StringBuilder sb = new StringBuilder();
ArrayList al;
try {
URL url = new URL("http://....login.php");
String param = "username=" + uname + "&password=" + pass;
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("POST");
connection.setConnectTimeout(15000);
connection.setReadTimeout(15000);
connection.setDoInput(true);
connection.setDoOutput(true);
OutputStream os = connection.getOutputStream();
BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(os, "UTF-8"));
bw.write(param);
bw.flush();
bw.close();
responseCode = connection.getResponseCode();
if (responseCode == HttpURLConnection.HTTP_OK) {
BufferedReader br = new BufferedReader(new InputStreamReader(connection.getInputStream()));
String line = "";
while ((line = br.readLine()) != null) {
sb.append(line + "\n");
}
}
data = sb.toString();
JSONObject json = new JSONObject(data);
status=json.getString("Status");//{"Login Status":"Success","Receipt Details":"No data available"}
// js=json.getString("Login");//{"Login":"Failed"}
} catch (MalformedURLException e) {
Log.i("MalformedURLException", e.getMessage());
} catch (IOException e) {
Log.i("IOException", e.getMessage());
} catch (JSONException e) {
Log.i("JSONException", e.getMessage());
}
return null;
}
protected void onPostExecute(Void result) {
super.onPostExecute(result);
String status1=status.trim();
if (status1.equals("Success")) {
Toast.makeText(getApplicationContext(), "Login Succes !!", Toast.LENGTH_SHORT).show();
Intent i = new Intent(Login.this, Home.class);
startActivity(i);
finish();
SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putBoolean("first_time", false);
editor.putString("userrname", uname);
editor.putString("password",pass);
editor.apply();
Toast.makeText(getApplicationContext(),"welcome : "+uname,Toast.LENGTH_LONG).show();
}
else {
Toast t=Toast.makeText(Login.this, "Username or Password is Incorrect", Toast.LENGTH_LONG);
t.setGravity(Gravity.BOTTOM,0,0);
t.show();
}
pdlg.dismiss();
}
}

You can use getErrorStream() ,
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
InputStream inp;
// if some error in connection
inp = connection.getErrorStream();
check this answer for more details..
according to the doc it returns
an error stream if any, null if there have been no errors, the
connection is not connected or the
server sent no useful data
.

use this two catch blocks to handle ConnectionTimeOut and socketTimeOut Exceptions
catch (SocketTimeoutException bug) {
Toast.makeText(getApplicationContext(), "Socket Timeout", Toast.LENGTH_LONG).show();
}
catch (ConnectTimeoutException bug) {
Toast.makeText(getApplicationContext(), "Connection Timeout", Toast.LENGTH_LONG).show();
}

For Connection time out add SocketTimeoutException in your catch block and its crashing because without null checking, you are trying to trim the string in onPostExecute
You should do like this, and check before using status
if(TextUtil.isEmpty(status)) {
pdlg.dismiss();
// We are getting empty response
return;
}
String status1=status.trim();

You can catch the Connection timeout exception in your code and then set the status according to your requirement and check for that status in onPostExecute to show the alert Dialog
try {
URL url = new URL("http://....login.php");
String param = "username=" + uname + "&password=" + pass;
// Your URL connection code here
catch (ConnectTimeoutException e) {
Log.e(TAG, "Timeout", e);
status="timeout"
} catch (SocketTimeoutException e) {
Log.e(TAG, " Socket timeout", e);
status="timeout"
}
in onPostExecute
if (status.equals("timeout")) {
// Show Alert Dialog.
}

What you are trying to do is previously done in some great networking lib. So I urge you to use one of the widley used network lib.
Volley.
Or if you want to understand you can just check the response status(or status code should be 408. I guess for connection time out) if it will return "connection time out" then you can call your code to the http client again to perform your task, you can also add a retry count to try for 2-3 times and then give up and send response to onpostexecute method.
Hope this helps.

Android - HttpsURLConnection - BAD REQUEST

I am trying to send a POST request using Plivo (VoIP server) to send a SMS to my cell phone, but I just receive BAD REQUEST (Request Code 400).
The error I received is "error": "invalid json data sent in raw POST"
I can't find where it's wrong.
Can someone help me?
final AsyncTask<String, Void, Boolean> request = new AsyncTask<String, Void, Boolean>() {
#Override
protected Boolean doInBackground(String... strings) {
Boolean retorno = true;
HttpsURLConnection request = null;
try {
request = (HttpsURLConnection) finalUrl.openConnection();
System.out.println("Define POST");
request.setRequestMethod("POST");
request.setUseCaches(false);
request.setDoOutput(true);
System.out.println("Define propriedades");
request.setRequestProperty("Content-Type", "application/json");
request.setRequestProperty("Accept", "application/json");
request.setRequestProperty("Accept-Charset", "UTF-8");
request.setRequestProperty("charset", "UTF-8");
System.out.println("Define autenticação");
String autenticacao = authID + ":" + authToken;
String basic = "Basic " + new String(Base64.encode(autenticacao.getBytes(), Base64.NO_WRAP));
request.setRequestProperty("Authorization", basic);
System.out.println("Define parâmetros");
JSONObject params = new JSONObject();
params.put("dst", numeroDestino);
params.put("src", numeroOrigem);
params.put("text", body);
System.out.println("Faz conexão e requisição");
request.connect();
OutputStreamWriter postParaEnvio = new OutputStreamWriter(request.getOutputStream());
postParaEnvio.write(URLEncoder.encode(params.toString(), "UTF-8"));
postParaEnvio.flush();
postParaEnvio.close();
int codigoStatus = request.getResponseCode();
for (Map.Entry<String, List<String>> header : request.getHeaderFields().entrySet()) {
System.out.println(header.getKey() + "=" + header.getValue());
}
if (codigoStatus == 202) {
System.out.println("OK");
} else {
System.out.println("Falha");
System.out.println(codigoStatus);
retorno = false;
}
} catch (IOException e) {
System.out.println("Falha Exception");
e.printStackTrace();
retorno = false;
} catch (JSONException e) {
e.printStackTrace();
retorno = false;
} finally {
request.disconnect();
}
return retorno;
}
#Override
protected void onPostExecute(Boolean result) {
indicadorDeAtividade.dismiss();
if(result) {
} else {
mostrarErro(0, R.string.erroEnviarCodigo);
}
}
}.execute();

SOLVED
When sending Json object, it must be passed to String but it cannot be coded.
Modifing the line postParaEnvio.write(URLEncoder.encode(params.toString(), "UTF-8")); to postParaEnvio.write(params.toString()); solved the problem.

I Think this may help you.
By the way,
My Dependencies : gradle->
compile 'com.android.support:appcompat-v7:23.4.0'
class BackGround extends AsyncTask<String, String, String> {
protected String doInBackground(String... params) {
String name = params[0];
String password = params[1];
String email = params[2];
String phone=params[3];
String data="";
int tmp;
try {
URL url = new URL("http://domain.com/yourFile.php");
String urlParams = "name="+name+"&password="+password+"&email="+email+"&phone="+phone;
HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
httpURLConnection.setDoOutput(true);
OutputStream os = httpURLConnection.getOutputStream();
os.write(urlParams.getBytes());
os.flush();
os.close();
InputStream is = httpURLConnection.getInputStream();
while((tmp=is.read())!=-1){
data+= (char)tmp;
}
is.close();
httpURLConnection.disconnect();
return data;
} catch (MalformedURLException e) {
e.printStackTrace();
return "Exception: "+e.getMessage();
} catch (IOException e) {
e.printStackTrace();
return "Exception: "+e.getMessage();
}
}
#Override
protected void onPostExecute(String s) {
if(s.equals("")){
s="Data Saved! Success...";
}
Toast.makeText(ctx, s, Toast.LENGTH_LONG).show();
}
}

HttpUrlConnection does not work on mobile device but on emulator

all of a sudden my mobile device can't connect to the local server anymore. async tasks are not executed and i just can't figure out why. slowly i'm getting really desperate because in my opinion i didn't change anything to cause this.
as an example, this is a background task which is not working
public class Login extends AsyncTask<String, Void, String>{
private String loginUrl = "http://...";
private int loginSuccess = 0;
public String getToken(String fromJson) throws JSONException {
JSONObject json = new JSONObject(fromJson);
if(json.has("api_authtoken")) {
loginSuccess = 1;
String appToken = json.getString("api_authtoken");
return appToken;
}
else {
return json.toString();
}
}
public String doInBackground(String... arg0) {
// so that they can be closed in the finally block.
HttpURLConnection urlConnection = null;
BufferedReader reader = null;
String authToken;
try {
// get logged in to get the api_authtoken
String email = (String) arg0[0];
String password = (String) arg0[1];
URL url = new URL(loginUrl);
// Create the request and open the connection
urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setRequestMethod("POST");
urlConnection.setRequestProperty("Content-Type", "application/json");
urlConnection.setRequestProperty("Accept", "application/json");
//put values of edittexts into json-Object
JSONObject data = new JSONObject();
try {
data.put("email", email);
data.put("password", password);
} catch(JSONException e) {
Log.e("EXCEPTION", "unexpected JSON exception", e);
e.printStackTrace();
}
urlConnection.connect();
OutputStreamWriter wr = new OutputStreamWriter(urlConnection.getOutputStream());
wr.write(data.toString());
wr.flush();
reader = new BufferedReader(new InputStreamReader(urlConnection.getInputStream()));
StringBuilder sb = new StringBuilder();
String line = null;
//read server response
while((line = reader.readLine()) != null) {
sb.append(line);
}
//receive server "answer"
try {
return getToken(sb.toString());
}catch(JSONException e) {
Log.e("LOG", "unexpected JSON exception", e);
e.printStackTrace();
} finally{
if (urlConnection != null) {
urlConnection.disconnect();
}
if (reader != null) {
try {
reader.close();
} catch (final IOException e) {
Log.e("MainActivity", "Error closing stream", e);
}
}
}
//return sb.toString();
return null;
}
catch(IOException e) {
Log.e("LoginTask", "Error ", e);
// If the code didn't successfully get the data, there's no point in attempting
// to parse it.
//forecastJsonStr = null;
return null;
}
}
public void onPostExecute(String result) {
super.onPostExecute(result);
//Log.v("RESULT", result);
if(result == null) {
CharSequence text = "no internet connection";
int duration = Toast.LENGTH_LONG;
Toast toast = Toast.makeText(MainActivity.this, text, duration);
toast.setGravity(Gravity.CENTER_VERTICAL, 0, 0);
toast.show();
}
if(loginSuccess == 0) {
// if the request wasn't successful
// give user a message via toast
CharSequence text = "wrong password or user. please try again";
int duration = Toast.LENGTH_LONG;
Toast toast = Toast.makeText(MainActivity.this, text, duration);
toast.setGravity(Gravity.CENTER_VERTICAL, 0, 0);
toast.show();
}
else {
// save token in shared preferences
SharedPreferences tokenPref = getSharedPreferences(getString(R.string.preference_token), Context.MODE_PRIVATE);
SharedPreferences.Editor editorToken = tokenPref.edit();
editorToken.putString(getString(R.string.saved_auth_token), result);
editorToken.commit();
//save login status = 1 in shared preferences
SharedPreferences loginPref = getSharedPreferences(getString(R.string.preference_logged_in), Context.MODE_PRIVATE);
SharedPreferences.Editor editorLogin = loginPref.edit();
editorLogin.putString(getString(R.string.saved_login), "1");
editorLogin.commit();
Intent mapsIntent = new Intent(getApplicationContext(), MapsActivity.class);
startActivity(mapsIntent);
}
}
}

HttpClient is not supported any more in sdk 23. You have to use URLConnection or downgrade to sdk 22 (compile 'com.android.support:appcompat-v7:22.2.0')
If you need sdk 23, add this to your gradle:
android {
useLibrary 'org.apache.http.legacy'
}
HttpClient won't import in Android Studio

You should think about using a HTTP library, there is a bunch of them on internet, some are really easy to use, optimize and errorless.
For example, Volley (made by Google, I really like this one), okHttp or Picasso (for image).
You should take a look at this.

If you want to send (output), for example with POST or PUT requests you need to use this :-
urlConnection.setDoOutput(true);
In your code :-
public class Login extends AsyncTask<String, Void, String>{
private String loginUrl = "http://...";
private int loginSuccess = 0;
public String getToken(String fromJson) throws JSONException {
JSONObject json = new JSONObject(fromJson);
if(json.has("api_authtoken")) {
loginSuccess = 1;
String appToken = json.getString("api_authtoken");
return appToken;
}
else {
return json.toString();
}
}
public String doInBackground(String... arg0) {
// so that they can be closed in the finally block.
HttpURLConnection urlConnection = null;
BufferedReader reader = null;
String authToken;
try {
// get logged in to get the api_authtoken
String email = (String) arg0[0];
String password = (String) arg0[1];
URL url = new URL(loginUrl);
// Create the request and open the connection
urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setRequestMethod("POST");
urlConnection.setRequestProperty("Content-Type", "application/json");
urlConnection.setRequestProperty("Accept", "application/json");
urlConnection.setDoOutput(true); // HERE
//put values of edittexts into json-Object
JSONObject data = new JSONObject();
try {
data.put("email", email);
data.put("password", password);
} catch(JSONException e) {
Log.e("EXCEPTION", "unexpected JSON exception", e);
e.printStackTrace();
}
OutputStreamWriter wr = new OutputStreamWriter(urlConnection.getOutputStream());
wr.write(data.toString());
wr.flush();
urlConnection.connect();
reader = new BufferedReader(new InputStreamReader(urlConnection.getInputStream()));
StringBuilder sb = new StringBuilder();
String line = null;
//read server response
while((line = reader.readLine()) != null) {
sb.append(line);
}
//receive server "answer"
try {
return getToken(sb.toString());
}catch(JSONException e) {
Log.e("LOG", "unexpected JSON exception", e);
e.printStackTrace();
} finally{
if (urlConnection != null) {
urlConnection.disconnect();
}
if (reader != null) {
try {
reader.close();
} catch (final IOException e) {
Log.e("MainActivity", "Error closing stream", e);
}
}
}
//return sb.toString();
return null;
}
catch(IOException e) {
Log.e("LoginTask", "Error ", e);
// If the code didn't successfully get the data, there's no point in attempting
// to parse it.
//forecastJsonStr = null;
return null;
}
}
public void onPostExecute(String result) {
super.onPostExecute(result);
//Log.v("RESULT", result);
if(result == null) {
CharSequence text = "no internet connection";
int duration = Toast.LENGTH_LONG;
Toast toast = Toast.makeText(MainActivity.this, text, duration);
toast.setGravity(Gravity.CENTER_VERTICAL, 0, 0);
toast.show();
}
if(loginSuccess == 0) {
// if the request wasn't successful
// give user a message via toast
CharSequence text = "wrong password or user. please try again";
int duration = Toast.LENGTH_LONG;
Toast toast = Toast.makeText(MainActivity.this, text, duration);
toast.setGravity(Gravity.CENTER_VERTICAL, 0, 0);
toast.show();
}
else {
// save token in shared preferences
SharedPreferences tokenPref = getSharedPreferences(getString(R.string.preference_token), Context.MODE_PRIVATE);
SharedPreferences.Editor editorToken = tokenPref.edit();
editorToken.putString(getString(R.string.saved_auth_token), result);
editorToken.commit();
//save login status = 1 in shared preferences
SharedPreferences loginPref = getSharedPreferences(getString(R.string.preference_logged_in), Context.MODE_PRIVATE);
SharedPreferences.Editor editorLogin = loginPref.edit();
editorLogin.putString(getString(R.string.saved_login), "1");
editorLogin.commit();
Intent mapsIntent = new Intent(getApplicationContext(), MapsActivity.class);
startActivity(mapsIntent);
}
}
}

android.os.NetworkOnMainThreadException

I am trying to set a url to my notification's setLargeIcon but while doing this I got the android.os.NetWorkOnMainThreadException error , I saw some posts that mention using AsyncTask, but I do not know how to implement that into my code.
#Override
public void onReceive(final Context context, Intent intent) {
Log.d(TAG, " START");
try {
if (intent == null)
{
Log.d(TAG, "Receiver intent null");
}
else
{
Log.d(TAG,intent.toString());
String action = intent.getAction();
Log.d(TAG, "got action " + action );
String channel = intent.getExtras().getString("com.parse.Channel");
JSONObject json = new JSONObject(intent.getExtras().getString("com.parse.Data"));
Log.d(TAG, "got action " + action + " on channel " + channel + " with:");
Iterator itr = json.keys();
while (itr.hasNext()) {
String key = (String) itr.next();
Log.d(TAG, "..."+key+ "=>" +json.getString(key));
if (key.equals("customdata"))
{
Log.d(TAG,"1.0");
msg=json.getString(key);
Log.d(TAG,msg.toString());
}
Log.d(TAG,"1.1");
if(key.equals("image_url"))
{
msg1=json.getString(key);
Log.d("msg1",msg1.toString());
}
}
Bitmap bitmap = getBitmapFromURL(msg1);
}
} catch (JSONException e) {
Log.d(TAG, "JSONException: " + e.getMessage());
}
}
public Bitmap getBitmapFromURL(String strURL) {
try {
URL url = new URL(strURL);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setDoInput(true);
connection.connect();
InputStream input = connection.getInputStream();
Bitmap myBitmap = BitmapFactory.decodeStream(input);
return myBitmap;
} catch (IOException e) {
e.printStackTrace();
return null;
}
}

you can use AsyncTask as:
class LoadBitmaps extends AsyncTask<String, Void, Void> {
#Override
protected void onPreExecute() {
// TODO Auto-generated method stub
super.onPreExecute();
// do something // show some progress of loading images
}
#Override
protected Void doInBackground(String... str) {
try {
URL url = new URL(str[0]);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setDoInput(true);
connection.connect();
InputStream input = connection.getInputStream();
Bitmap myBitmap = BitmapFactory.decodeStream(input);
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(Void v) {
// do something
}
}

This exception occurred because you getting the data from network in the main thread. Move it to AsyncTask's onBackground or a Thread so the process of getting data will be on background thread. Example (using a Thread) :
Thread thread = new Thread(new Runnable(){
#Override
public void run() {
try {
getBitmapFromURL(url);
} catch (Exception e) {
e.printStackTrace();
}
}
});
thread.start();
Take a look here if you are not sure whether to use Thread or AsyncTask :
Asynctask vs Thread in android