Develop Reference

loading data from the list when android app open

Hi I just created app for loading data from the website once the button is clicked in android.I want to change the app for loading data when the application open.How will I do it?
Here is my code..
public class PrimaryActivity extends Activity {
private static final String URL = "http://livechennai.com/powershutdown_news_chennai.asp";
ProgressDialog mProgressDialog;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_primary);
Button btnFetchData = (Button) findViewById(R.id.btnData);
btnFetchData.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
new FetchWebsiteData().execute();
}
});
}
private class FetchWebsiteData extends AsyncTask<Void, Void, String[]> {
String websiteTitle, websiteDescription,websiteDescription1,websiteDescription2,websiteDescription3,listValue,listValue1;
ProgressDialog progress;
#Override
protected void onPreExecute() {
super.onPreExecute();
//some code here
}
#Override
protected String[] doInBackground(Void... params) {
ArrayList<String> hrefs=new ArrayList<String>();
try {
// parsing here
}
} catch (IOException e) {
e.printStackTrace();
}
//get the array list values
for(String s:hrefs)
{
//website data
}
//parsing first URL
} catch (IOException e) {
e.printStackTrace();
}
//parsing second URL
} catch (IOException e) {
e.printStackTrace();
}
try{
List<String> listString = new ArrayList<String>(Arrays.asList(resultArray));
listString.addAll(Arrays.asList(resultArray1));
String [] outResult= new String[listString.size()];
int i=0;
for(String str: listString){
outResult[i]=str;
i++;
}
return outResult;
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(String[] result) {
ListView list=(ListView)findViewById(R.id.listShow);
ArrayAdapter<String> arrayAdapter=new ArrayAdapter<String>(getBaseContext(),android.R.layout.simple_list_item_1,result);
list.setAdapter(arrayAdapter);
mProgressDialog.dismiss();
}
}
}
How to load the list view when we open the app? help me to get the exact answer?

Just load it in onCreate. This is what will be called when the app is opened first. Then read about other events like onResume.
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_primary);
new FetchWebsiteData().execute();
}

Call FetchWebsiteData().execute() from one of the activity lifecycle methods such as onStart, onCreate, or onResume - please refer to docs to determine which fits in your case.

Put the method which does the fetching i.e. new FetchWebsiteData().execute(); outside of the code of button click and in the activity.onResume() method.
onResume is called everytime an app comes to foreground, if you put it oncreate(), the method will be called only when the activity is created.

How to get updated value of EditText in Android

I'm new to android and working on a basic screen to use a web-service with android application.
I am posting values using AsyncTask and fetching the result from the webservice. It works fine until displaying the returned value. While displaying the Toast Message on click, I get old value of TextView resultReturned
public class TestPost extends Activity{
private TextView result = null;
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.my_screen);
result = (TextView)findViewById(R.id.resultReturned);
Button submit = (Button)findViewById(R.id.btnSubmit);
submit.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String[] strPost = new String[]{"value1", "value2"};
SendAsyncRequest asyncSend = new SendAsyncRequest();
asyncSend.execute(strPost);
// ResultView retains old value and gets correct value on second click
String returned = result.getText().toString();
Toast.makeText(getApplicationContext(), returned, Toast.LENGTH_LONG).show();
}
});
}
public class SendAsyncRequest extends AsyncTask<String, Void, String>{
private String fetchedData = "";
#Override
protected String doInBackground(String... params ) {
// perform async task
return fetchedData;
}
#Override
protected void onPostExecute(String result) {
setReturedValue(result);
}
}
private void setReturedValue(String data){
result.setText(data);
}
So, how do I get the updated text value of the TextView?

AsyncTask takes time to get response from request, Show toast message in postExecute() method, like this, and remove from onclick.
#Override
protected void onPostExecute(String result) {
Toast.makeText(getApplicationContext(), result, Toast.LENGTH_LONG).show();
}

Try this
submit.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String[] strPost = new String[]{"value1", "value2"};
SendAsyncRequest asyncSend = new SendAsyncRequest();
asyncSend.execute(strPost);
// ResultView retains old value and gets correct value on second click
String jsonResult;
try {
jsonResult=asyncSend.get();
} catch (InterruptedException | ExecutionException e) {
e.printStackTrace();
}
Toast.makeText(getApplicationContext(), jsonResult, Toast.LENGTH_LONG).show();
}
});
And return your Json String in doInBackground().

android html parsing with jsoup

Trying to parse an html pages like http://www.ts.kg/serials/ on android. Tried to do it with htmlcleaner, but it didnot work. Trying to do it with jsoup. In the begining was my code to complex. Here is the shortest code. The same thing works on java Please help. My Logs http://smartpics.kz/imgs/1361209668WW5O.JPG
Here is my class:
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
String[] names= {};
String url = "http://www.ts.kg/mults/";
try {
Document doc = Jsoup.connect(url).get();
Element e = doc.body();
Elements ggg = e.getElementsByAttributeValue("class", "categoryblocks");
for (int i =0;i<ggg.size();i++) {
Element linkk = ggg.get(i);
if(linkk.getElementsByTag("a")!=null){
Element atom = linkk.getElementsByTag("a").first();
String n = atom.getElementsByTag("span").first().text();
names[i] = n;
}
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
ListView lvMain = (ListView) findViewById(R.id.listViewData);
// создаем адаптер
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1, names);
// присваиваем адаптер списку
lvMain.setAdapter(adapter);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
}
posted 20.feb.2013:
tryed to do it as it was proposed by Shoshy (thanks for your answer), but it didn't work (perhaps because of my not-from-right-place-growing hands). Here is my modified code:
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
url = "http://www.ts.kg/mults/";
pd = ProgressDialog.show(MainActivity.this, "Working...", "request to server", true, false);
//Запускаем парсинг
new AsyncExecution().execute();
}
private ProgressDialog pd;
String url;;
String names[];
private class AsyncExecution extends AsyncTask<Void, Void, Void>{
#Override
protected Void doInBackground(Void... params) {
// here your task will be done in seperate thread from UI thread
// and if you want to use the variables (that will be modifed here)
// from anywhere in MainActivity, then you should declare them as global
// variable in MainActivity. remember you cannot update UI from here , like
// Toast message. if you want to do that you can use OnPostExecute
// method bellow .
try {
ArrayList<String> array = new ArrayList<String>();
Document doc = Jsoup.connect(url).get();
Element e = doc.body();
Elements ggg = e.getElementsByAttributeValue("class", "categoryblocks");
for (int i =0;i<ggg.size();i++) {
Element linkk = ggg.get(i);
if(linkk.getElementsByTag("a")!=null){
Element atom = linkk.getElementsByTag("a").first();
String n = atom.getElementsByTag("span").first().text();
array.add(n);
}
}
for (int i = 0;i<array.size();i++){
names[i]=array.get(i);
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(Void result) {
//Убираем диалог загрузки
pd.dismiss();
//Находим ListView
ListView listview = (ListView) findViewById(R.id.listViewData);
//Загружаем в него результат работы doInBackground
listview.setAdapter(new ArrayAdapter<String>(MainActivity.this,
android.R.layout.simple_list_item_1, names));
}
}
}

you have to make the request for getting the page in another thread from UI thread. you can use AsyncTask. i am giving some example by editing your code :
the link about AsyncTask is : about AsynckTask
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//the class is defined bellow
new AsyncExecution().execute();
//other codes.....
.......................
}
/// your other codes .....
// you need to add this class
private class AsyncExecution extends AsyncTask<Void, Void, Void>{
#Override
protected Void doInBackground(Void... params) {
// here your task will be done in seperate thread from UI thread
// and if you want to use the variables (that will be modifed here)
// from anywhere in MainActivity, then you should declare them as global
// variable in MainActivity. remember you cannot update UI from here , like
// Toast message. if you want to do that you can use OnPostExecute
// method bellow .
try {
Document doc = Jsoup.connect(url).get();
Element e = doc.body();
Elements ggg = e.getElementsByAttributeValue("class", "categoryblocks");
for (int i =0;i<ggg.size();i++) {
Element linkk = ggg.get(i);
if(linkk.getElementsByTag("a")!=null){
Element atom = linkk.getElementsByTag("a").first();
String n = atom.getElementsByTag("span").first().text();
names[i] = n;
}
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
#Override
protected void onPostExecute(Void result) {
}
}

AsyncTask as Inner class and static field issue

I have a method searchPlace() that updates a static Arrays of custom Place Object in a class A (FindItOnMap) with a google map, and a method updateMap() that updates the various geopoints .
I invoke these methods Button.onClick and all works properly.
Since these methods use internet data this operation could take a while, I have been looking for the implementation of an inner class B(YourCustomAsyncTask) inside the class A that extends AsyncTask to show a waiting dialog during the processing of these two methods
An user suggested a solution in this form (that apparently seems valid):
public class FindItOnMap extends MapActivity {
static Place[] foundResults;
private ProgressDialog dialog;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.ricerca_condominio);
mapView = (MapView)findViewById(R.id.mapView);
...........
((ImageButton) findViewById(R.id.btSearch)).setOnClickListener(mSearchListenerListener);
}
OnClickListener mSearchListener = new OnClickListener() {
public void onClick(View v) {
String location=editorLocation.getText().toString();
String name=editorName.getText().toString();
//Call the AsyncTask here
new YourCustomAsyncTask().execute(new String[] {name, location});
}
};
private class YourCustomAsyncTask extends AsyncTask <String, Void, Void> {
#Override
protected void onPreExecute() {
dialog = new ProgressDialog(Main.this);
dialog.setMessage("Loading....");
dialog.setIndeterminate(true);
dialog.setCancelable(true);
dialog.show(); //Maybe you should call it in ruinOnUIThread in doInBackGround as suggested from a previous answer
}
#Override
protected Void doInBackground(String... strings) {
try {
search(strings[0], string[1]);
return null;
} catch(Exception e) {
}
}
#Override
protected void onPostExecute(Void params) {
updateMapWithResult();
dialog.dismiss();
//result
}
.....
}
The waiting dialog is showed and the methods are invoked in background,
However for some strange reason the static list foundResults results filled with various null items...
How is this possible?
If I invoke the method search(location, name) outside the inner class all works properly and updateMapWithResult(); updates all geopoint, so these two methods are ok. Only if I try to invoke this in the inner class the json calls seem to be working but the static variable foundResults is filled with null elements and the program doesn't work properly.
Any suggestion?

I have understand where is the problem.
You have to run the search method on the UI thread.
So change this code block:
#Override
protected Void doInBackground(String... strings) {
try {
search(strings[0], string[1]);
return null;
} catch(Exception e) {
}
}
with this
#Override
protected Void doInBackground(final String... strings) {
try {
runOnUiThread(new Runnable() {
public void run() {
search(strings[0], string[1]);
return null;
}
});
} catch(Exception e) {
e.printStackTrace();
}
}
And all should works correctly.

Here is one problem:
OnClickListener mSearchListener = new OnClickListener() {
public void onClick(View v) {
String Location=editorLocation.getText().toString();
String name=editorName.getText().toString();
//Call the AsyncTask here
new YourCustomAsyncTask().execute(new String[] {name, location});
}
Your Location should be location.
Also here:
#Override
protected Void doInBackground(String... strings) {
try {
search(strings[0], string[1]);
} catch(Exception e) {
}
}
#Override
protected void onPostExecute(Void params) {
updateMapWithResult();
dialog.dismiss();
//result
}
In doInBackground you don't assign a value after you search. You might try this:
#Override
protected Void doInBackground(String... strings) {
try {
search(strings[0], string[1]);
String name = string[0];
String location = string[1]
} catch(Exception e) {
}
}
Or something else that will assign value while it runs. As it is, it appears that you just search, and then nothing else.
The reason foundResults is null is because you don't ever assign it a value.

There is nothing wrong with your AsyncTask. Please include the search() method.

Passing parameters to Asynctask

I am using Async tasks to get string from the menu activity and load up some stuff..but i am
not able to do so..Am i using it in the right way and am i passing the parameters correctly?
Please see the code snippet. thanks
private class Setup extends AsyncTask<Void, Integer, Void> {
#Override
protected Void doInBackground(Void... params) {
try {
if (!(getIntent().getExtras().isEmpty())) {
Bundle gotid = getIntent().getExtras();
identifier = gotid.getString("key");
}
} catch (Exception e) {
e.getStackTrace();
} finally {
if (identifier.matches("abc")) {
publishProgress(0);
db.insert_fri();
} else if ((identifier.matches("xyz"))) {
publishProgress(1);
db.insert_met();
}
}
return null;
}
#Override
protected void onProgressUpdate(Integer... i) {
// start the song here
if (i[0] == 0) {
song.setLooping(true);
song.start();
}
}
#Override
protected void onPostExecute(Void res) {
}
#Override
protected void onPreExecute() {
// do something before execution
}
}

Avoid adding a constructor.
Simply pass your paramters in the task execute method
new BackgroundTask().execute(a, b, c); // can have any number of params
Now your background class should look like this
public class BackgroundTask extends AsyncTask<String, Integer, Long> {
#Override
protected Long doInBackground(String... arg0) {
// TODO Auto-generated method stub
String a = arg0[0];
String b = arg0[1];
String c = arg0[2];
//Do the heavy task with a,b,c
return null;
}
//you can keep other methods as well postExecute , preExecute, etc
}

Instead of this i would do
private class Setup extends AsyncTask<String, Integer, Void> {
#Override
protected Void doInBackground(String... params) {
String identifier = params[0];
if (identifier.matches("abc")) {
publishProgress(0);
db.insert_fri();
} else if ((identifier.matches("xyz"))) {
publishProgress(1);
db.insert_met();
}
}
return null;
}
#Override
protected void onProgressUpdate(Integer... i) {
// start the song here
if (i[0] == 0) {
song.setLooping(true);
song.start();
}
}
#Override
protected void onPostExecute(Void res) {
}
#Override
protected void onPreExecute() {
// do something before execution
}
}
and check for "identifier" before invoking the asynctask to prevent overhead of creating a AsyncTask
like this
if (!(getIntent().getExtras().isEmpty())) {
Bundle gotid = getIntent().getExtras();
identifier = gotid.getString("key");
new Setup().execute(identifier);
}

A simple way is to add a constructor:
public Setup(String a, Int b) {
this.a = a;
this.b = b;
}

AsyncTask means doInBackground() returns Void, onProgressUpdate() takes Integer params and doInbackground takes... String params !
So you don't need (and REALLY shouldn't) use Intent, since it is meant to be used for passing arguments through Activities, not Threads.
And as told before, you can make a constructor and a global parameter to your class called "identifier"
public class Setup...
{
private String identifier;
public Setup(String a) {
identifier = a;
}
}
Hoped it could help.
Regards