Develop Reference

Android: ProgressDialog in external async class (sth block async thread)

I have main activity:
public class ChooseWriteSentenceActivity extends ActionBarActivity{
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
String userName = "Zdzisiu";
String password = "Ziemniak";
MainServie service = new MainService(this);
boolean isExsist = service.findUser(String userName, String password);
//more code...
}
}
In my app service uses repositories and jsonconsumers but for simpler code I'm skipping them.
public class MyService{
private Context context;
public MyService(Context context){
this.context = context
}
public boolean findUser(String userName, String password){
String resultS = null;
try{
resultS = new QueryExecutorFindUser(context).execute(userName,password).get();
}
catch(Exception ex){
ex.printStackTrace();
}
boolean realRes = jsonConsumer(resultS).getFindUser();
return realRes;
}
}
public class QueryExecutorFindUser extends AsyncTask<String,Void,String> {
protected final String connectionUrl = "http://myWebService:44302/Service.svc/";
protected ProgressDialog progressDialog;
protected Context curContext;
public QueryExecutor(Context context){
curContext = context;
}
#Override
protected void onPreExecute()
{
super.onPreExecute();
progressDialog = ProgressDialog.show(curContext,"Loading...",
"Loading application View, please wait...", false, false);
}
#Override
protected void onPostExecute(String result)
{
super.onPostExecute(result);
progressDialog.dismiss();
}
protected String doInBackground(String... args){
String result = null;
String url = connectionUrl + args[0] + "/" + args[1];
HttpResponse response = null;
HttpClient httpclient = this.getNewHttpClient();
HttpGet get = new HttpGet(url);
get.setHeader("Accept", "application/json");
get.setHeader("Content-type", "application/json");
try{
response = httpclient.execute(get);
StatusLine statusLine = response.getStatusLine();
if(statusLine.getStatusCode() == HttpStatus.SC_OK){
if(response != null){
ByteArrayOutputStream out = new ByteArrayOutputStream();
response.getEntity().writeTo(out);
out.close();
result = out.toString();
}
} else{
throw new IOException(statusLine.getReasonPhrase());
}
} catch(Exception ex){
ex.getMessage();
} finally{
if(response != null){
try{
response.getEntity().getContent().close();
} catch(Exception ex){
}
}
}
return result;
}
}
And progress dialog is show but only after all code in onCreatre in ChooseWriteSentenceActivity including doInBacground(...) from QueryExecutor is finished (so it disappears practically at the same time). It looks like sth waiting for thread with QueryExecutorFindUser.doInBackground() and it is runs like synchronously (?), I think that because when I debug code onPreExecute() is running correctly (and start before doInBackground(...)) and progressDialog.isShowing() == true (but not on the screen :( ).
If I remove extends AsyncTask from QueryExecutorFindUser and make private class with this extension in main activity (and run all code from onCreated() including service.findUser() in thisPrivateClass.doInBackground(...)) it works okey.
I prefer to have progressDialog in one place no in all main activities (of cource in practise I use QueryExecutor for all queries not only findUser) but I don't have idea what i am doing wrong. I spent all day on it with no result :(

Dialogs are tied to an Activity and ultimately must be hosted by one. So until your app's activity gets created, the dialog will not display.

Checking the AsyncTask status seems not working correctly (log doesn't appear on log cat)

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.

Convert android AsyncTask call to a separate class and call from all activities

I am new to android development. I have a AsyncTask function in my application. Calling http request from all activities. Now in each activity I am using the following class to connect to server, in some activities I even called twice !!.
Basically I am a web developer and in such cases we use a single class which can be accessed from entire application(web) and use the common function to do the same activity. The only difference is input and out put will be changed.
My doubt is in this case can I use ( convert) this to such a function or class ?
My assume is
Create an android class ( which can be accessed from all the activities )
Just make the JSON string we need with specific server ( for process in server )
Just pass the created json to the created class and then made the http connect )
Process the returned data from server
Pass that to the corresponding activity
So that I can use the same function for all the activities and I can avoid duplicate query
Can I convert this code to such a manner ?
My Code
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setRequestedOrientation (ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
setContentView(R.layout.activity_main);
LogIN loginUser = new LogIN();
LoginUser.execute("");
}
private class LogIN extends AsyncTask<String, Integer, String> {
#Override
protected String doInBackground(String... sUrl) {
try {
String path = "http://www.domain_name.com/app/checkSession.php";
HttpClient client = new DefaultHttpClient();
HttpConnectionParams.setConnectionTimeout(client.getParams(), 10000);
HttpResponse response;
JSONObject json = new JSONObject();
try {
HttpPost post = new HttpPost(path);
json.put("access_token", "123456");
post.setHeader("json", json.toString());
StringEntity se = new StringEntity(json.toString());
se.setContentEncoding((Header) new BasicHeader(HTTP.CONTENT_TYPE, "application/json"));
post.setEntity(se);
response = client.execute(post);
/* Checking response */
if (response != null) {
InputStream in = response.getEntity().getContent();
String a = convertStreamToString(in);
JSONObject jsono = stringToJsonobj(a);
String passedStringValue = jsono.getString("result");
if(passedStringValue.equals("1")){
flags=1;
//Log.v("TAGG", "Success");
}
else {
flags=0;
//Log.v("TAGG", "Failed !");
}
}
} catch (Exception e) {
e.printStackTrace();
}
} catch (Exception e) {
}
return null;
}
#Override
protected void onPreExecute() {
super.onPreExecute();
showDialogue("Login Processing", "Loading");
}
#Override
protected void onProgressUpdate(Integer... progress) {
super.onProgressUpdate(progress);
}
#Override
protected void onPostExecute(String result) {
if(flags.equals(1)){
Itent homepage = new Intent(MainActivity.this, RegisterDevice.class);
startActivity(homepage);
finish();
}
else {
Intent homepage = new Intent(MainActivity.this, LoginActivity.class);
startActivity(homepage);
finish();
}
super.onPostExecute(result);
}
}
}
Please any one help/advise
Thanks in advance

Extract your class to a different file and make it public
public class LogIN extends AsyncTask<Object, Integer, String> {
private ILoginListener listener;
#Override
protected String doInBackground(Object... arg0) {
try {
this.listener = (ILoginListener) arg0[0];
//You can also send the url in the obj array
String theUrl = (String) arg0[1];
String path = "http://www.domain_name.com/app/checkSession.php";
HttpClient client = new DefaultHttpClient();
HttpConnectionParams.setConnectionTimeout(client.getParams(), 10000);
HttpResponse response;
JSONObject json = new JSONObject();
try {
HttpPost post = new HttpPost(path);
json.put("access_token", "123456");
post.setHeader("json", json.toString());
StringEntity se = new StringEntity(json.toString());
se.setContentEncoding((Header) new BasicHeader(HTTP.CONTENT_TYPE, "application/json"));
post.setEntity(se);
response = client.execute(post);
/* Checking response */
if (response != null) {
InputStream in = response.getEntity().getContent();
String a = convertStreamToString(in);
JSONObject jsono = stringToJsonobj(a);
String passedStringValue = jsono.getString("result");
if(passedStringValue.equals("1")){
flags=1;
//Log.v("TAGG", "Success");
}
else {
flags=0;
//Log.v("TAGG", "Failed !");
}
}
} catch (Exception e) {
e.printStackTrace();
}
} catch (Exception e) {
}
return null;
}
#Override
protected void onPreExecute() {
super.onPreExecute();
showDialogue("Login Processing", "Loading");
}
#Override
protected void onProgressUpdate(Integer... progress) {
super.onProgressUpdate(progress);
}
#Override
protected void onPostExecute(String result) {
listener.logInSessionCheckListener(flag.equals(1));
super.onPostExecute(result);
}
}
Regarding your other question, I normally have an interface for that, something like this:
public interface ILoginListener {
public void logInSessionCheckListener(SomeNeeded Value);
}
I implement the interface in the class where i need the postExecute result and in the overriden method you can to what you want with the result of your task.
Your class where you user it will look something like this:
public class SomeClass implements ILoginListener {
//Call it like this from any class:
LogIN loginTask = new LogIn();
Object[] someParams = new Object[2];
//add the listener
someParams[0] = SomeClass.this
//add the url
someParams[1] = someUrlString;
loginTask.execute(someParams);
#Override
public void logInSessionCheckListener(SomeNeeded Value){
//do Stuff with your results
}
}

You can do it like make separate class for everything inside doInBackground() method and called it in all activity with passing parameter to
LogIN loginUser = new LogIN(yourparameter);
LoginUser.execute("");
and check parameter in AsyncTask Class constructor like
public LogIN(Myparameter){
// Your data
}

On the other hand you can use this great framework for android : android-query and the async API.
It allows you to perform asynchroneous network tasks from activities and easily work with the results of your requests.

You should use interfaces to implement a callback to your ui activity.
Have a look at this thread, it might be useful:
android asynctask sending callbacks to ui
And your asyntask class should be in a seperate java file with public acces.
And to pass the parametres you simply have to call a new LogIN async Task like this:
new LogIN().execute(urls);
Hope it helped :)

Remember that you can never know when AsyncTask is going to finish. So if you're using this to authenticate users and then perform task X, task Y, or task Z,
then maybe it's better to create a Login helper class
public class LoginHelper {
public boolean login(params){
// Authenticate user and return true if successfull
}
}
and then have in your Activity classes
private class X extends AsyncTask {
#Override
protected String doInBackground(String... sUrl) {
...
boolean authenticated = LoginHelper.login(params...);
if(authenticated == true) {
// Perform task X here...
} else {
// Inform the user that the login failed...
}
}

First of all
You have to pass the context in which you are calling your async task
Sample Code
Login loginTask = new Long(getContext());
loginTask.execute();
You class Login should have a constructor that accepts the Context
Sample Code
public class Login extends AsyncTask<String, Integer, String> {
private Context mContext ;
private ProgressDialog pd;
private Handler handler = new Handler { };
public Login (Context context){
mContext = context ;
}
.....
Then make sure to create the method showDialog inside Login class to show the progress dialog
Note
You can add what ever Constructors you need to customize the behaviour of your Login task
for example : pass boolean parameter to tell that the Login Task is cancelable....
Hope that help you :)

Read data from database located at server in android

I have one database file whose name is menu.db and this file is located at server now i want to read data from this database.
i also have registration page on the application i am working on, as user press submit button then all the user information should be store on that database at server.
if anyone solved this problem then please help me.
if any one knows then please help me.

I have the following code. It authenticates the user password. you should call this method inside doBackground() of AsyncTask extended Class.
public boolean authenticate(String strUsername, String strPassword)
{
boolean bReturn = false;
InputStream pInputStream = null;
ArrayList<NameValuePair> pNameValuePairs = new ArrayList<NameValuePair>();
pNameValuePairs.add(new BasicNameValuePair("userid", strUsername));
pNameValuePairs.add(new BasicNameValuePair("password", strPassword));
try
{
HttpClient pHttpClient = new DefaultHttpClient();
String strURL = p_strServerIP + "Login.php";
HttpPost pHttpPost = new HttpPost(strURL);
pHttpPost.setEntity(new UrlEncodedFormEntity(pNameValuePairs));
HttpResponse pHttpResponse = pHttpClient.execute(pHttpPost);
HttpEntity pHttpEntity = pHttpResponse.getEntity();
pInputStream = pHttpEntity.getContent();
BufferedReader pBufferedReader = new BufferedReader(new InputStreamReader(pInputStream,"iso-8859-1"),8);
StringBuilder pStringBuilder = new StringBuilder();
String strLine = pBufferedReader.readLine();
pInputStream.close();
if(strLine != null)
{
if((strLine).equals("permit"))
{
bReturn = true;
}
}
}
catch (Exception e)
{
Log.e("log_tag", "Caught Exception # authenticate(String strUsername, String strPassword):" + e.toString());
}
return bReturn;
}
The class you extend from AsyncTask should be something like
class ConnectionTask extends AsyncTask<String, Void, Boolean>
{
private SharedPreferences mSettings;
private Context mContext;
ConnectionTask(SharedPreferences settings, Context context)
{
mSettings = settings;
mContext = context;
}
protected void onProgressUpdate(Integer... progress)
{
}
protected void onPostExecute(Boolean result)
{
Toast.makeText(mContext, "Authentication over.", Toast.LENGTH_LONG).show();
}
#Override
protected Boolean doInBackground(String... params)
{
pVerifier.authenticate(params[0], params[1]);
return true;
}
}

check amount data uploaded to the server

how to check the amount of data in each time uploaded to the server, this is my code which I call inside a AsyncTask
public String conxDatosInPost(String Direccion, ArrayList<NameValuePair> Parametros) throws Exception {
BufferedReader in = null;
try {
HttpClient client = ClienteHttp();
HttpPost request = new HttpPost(Direccion);
UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(Parametros);
request.setEntity(formEntity);
HttpResponse response = client.execute(request);
//long logitud = response.getEntity().getContentLength();
in = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
StringBuffer sb = new StringBuffer("");
String line = "";
String NL = System.getProperty("line.separator");
while ((line = in.readLine()) != null) {
sb.append(line + NL);
}
in.close();
String result = sb.toString();
Log.d("El resultado de cnxposin es :----------- ", result +"fn");
return result;
} finally {
if (in != null) {
try {
in.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
This is my class CLienteHttp();
private HttpClient ClienteHttp() {
if (mHttpCliente == null) {
public static final int HTTP_TIMEOUT = 30 * 1000; // milliseconds
mHttpCliente = new DefaultHttpClient();
final HttpParams params = mHttpCliente.getParams();
HttpConnectionParams.setConnectionTimeout(params, HTTP_TIMEOUT);
HttpConnectionParams.setSoTimeout(params, HTTP_TIMEOUT);
ConnManagerParams.setTimeout(params, HTTP_TIMEOUT);
}
return mHttpCliente;
}
And this is my class asyncTask
public class NuevoPostImagen extends AsyncTask<String, Integer, String>{
#Override
protected String doInBackground(String... params) {
objAcceso = new AccesoBd();
String jsRes="";
SharedPreferences userDetails = getParent().getSharedPreferences("MisPreferencias", MODE_PRIVATE);
ArrayList<NameValuePair> ParametrosDeEnvio = new ArrayList<NameValuePair>();
ParametrosDeEnvio.add(new BasicNameValuePair("from",Integer.toString(userDetails.getInt("Id",0))));
ParametrosDeEnvio.add(new BasicNameValuePair("idrecurso",Integer.toString(idEvento)));
ParametrosDeEnvio.add(new BasicNameValuePair("texto","nada"));
ParametrosDeEnvio.add(new BasicNameValuePair("titulo",txtFTitulo.getText().toString()));
ParametrosDeEnvio.add(new BasicNameValuePair("imageFile",sImagenBsase64));
try{
//here
String jes=objAcceso.conxDatosInPost(params[0],ParametrosDeEnvio);
jsRes = "ok";
} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}finally{return jsRes;}
}
#Override
public void onProgressUpdate(Integer... args){
Pro.setProgress(args[0]);
}
#Override
protected void onPostExecute( String result) {
Pro.dismiss();
if (result.toString().equals("ok")){
LlenarEvento();
dOpciones.dismiss();
dHacerFoto.dismiss();
}
}
#Override
protected void onPreExecute() {
Pro = ProgressDialog.show(getParent(), "", "Enviando",true,true);
Pro.setCancelable(false);
}
}
Can I update my progress bar with the existing code?
Once the cliente.execute (httpost).
I wonder how I can put a listener or something to check the number of bytes uploaded being updated every second or every time you upload them? I need to update my progress bar, according to the quantity that has been uploaded.
Please, I can help?

You can use async task for this. you have to over ride 3 methods.
doinbackground()
onpreexecute()
onpostexecute()
onProgressUpdate
i think this will help u to understand hw to do it . How to implement file upload progress bar in android