I'm new at android.I'm trying to develop a client app.Anyway,I have user profile activity which has friends and followers and counts are being showed with textview. When a user click on count of followers textview see friends list on dialog box as a listview. it is created an apiclient object for retrieving data as a json format from server.
friendsCountTxtView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
MyTApiClients apiclients = new MyApiClients(session);
apiclients.getFriendsListService().show(userID, userName, -1, countForList, new Callback<Response>() {
#Override
public void success(Result<Response> result) {
BufferedReader reader;
StringBuilder sb = new StringBuilder();
try {
reader = new BufferedReader(new InputStreamReader(result.response.getBody().in()));
String line;
while ((line = reader.readLine()) != null) {
sb.append(line);
}
} catch (IOException e) {
e.printStackTrace();
}
String jsonResult = sb.toString();
try {
JSONObject objResult = new JSONObject(jsonResult);
nextCursor = Long.parseLong(objResult.getString("next_cursor"));
ListViewLoaderTask listViewLoaderTask = new ListViewLoaderTask();
listViewLoaderTask.execute(jsonResult);
} catch (JSONException e) {
e.printStackTrace();
}
}
#Override
public void failure(Exception e) {
}
});
}
});
I used an asyncTask for parsing jsonobject and binding it listview.
private class ListViewLoaderTask extends AsyncTask<String, Void, SimpleAdapter> {
JSONObject jObject;
/** Returning an Adapter For Using Post Execute*/
#Override
protected SimpleAdapter doInBackground(String... strJson) {
try{
jObject = new JSONObject(strJson[0]);
UserProfileJsonParser userProfileJsonParser = new UserProfileJsonParser();
userProfileJsonParser.parse(jObject);
}catch(Exception e){
Log.d("JSON Exception1", e.toString());
}
UserProfileJsonParser userProfileJsonParser = new UserProfileJsonParser();
List<HashMap<String, String>> userProfiles = null;
try{
/** Getting the parsed data as a List construct */
userProfiles = userProfileJsonParser.parse(jObject);
}catch(Exception e){
Log.d("Exception",e.toString());
}
/** Keys used in Hashmap */
String[] from = { "name","screen_name"};
/** Ids of views in listview_layout */
int[] to = { R.id.name,R.id.screen_name};
SimpleAdapter adapter = new SimpleAdapter(UserProfileActivity.this, userProfiles, R.layout.friends_list_items_layout, from, to);
return adapter;
}
/** Invoked by the Android system on "doInBackground" is executed completely */
/** This will be executed in ui thread */
#Override
protected void onPostExecute(final SimpleAdapter adapter) {
dialoglist.setAdapter(adapter);
builder.setView(dialoglist);
if (!isDialogBoxOpen)
{
isDialogBoxOpen = true;
final Dialog dialog = builder.create();
dialog.show();
}
}
}
Later when user scrolls listview it executes another async method for loading more data.
dialoglist.setOnScrollListener(new OnScrollListener() {
private int currentVisibleItemCount;
private int currentScrollState;
private int currentFirstVisibleItem;
private int totalItem;
#Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
// TODO Auto-generated method stub
int threshold = 1;
int count = dialoglist.getCount();
if (scrollState == SCROLL_STATE_IDLE) {
if (dialoglist.getLastVisiblePosition() >= count
- threshold) {
// Execute LoadMoreDataTask AsyncTask
new LoadMoreDataTask().execute();
}
}
this.currentScrollState = scrollState;
this.isScrollCompleted();
}
#Override
public void onScroll(AbsListView view, int firstVisibleItem,
int visibleItemCount, int totalItemCount) {
// TODO Auto-generated method stub
this.currentFirstVisibleItem = firstVisibleItem;
this.currentVisibleItemCount = visibleItemCount;
this.totalItem = totalItemCount;
}
private void isScrollCompleted() {
if (totalItem - currentFirstVisibleItem == currentVisibleItemCount
&& this.currentScrollState == SCROLL_STATE_IDLE) {
/** To do code here*/
}
}
});
}
private class LoadMoreDataTask extends AsyncTask<Void, Void, Void> {
#Override
protected Void doInBackground(Void... params) {
MyApiClients apiclients = new MyApiClients(session);
apiclients.getFriendsListService().show(userID, userName, nextCursor, countForList, new Callback<Response>() {
#Override
public void success(Result<Response> result) {
BufferedReader reader = null;
StringBuilder sb = new StringBuilder();
try {
reader = new BufferedReader(new InputStreamReader(result.response.getBody().in()));
String line;
while ((line = reader.readLine()) != null) {
sb.append(line);
}
} catch (IOException e) {
e.printStackTrace();
}
String jsonResult = sb.toString();
try {
JSONObject objResult = new JSONObject(jsonResult);
nextCursor = Long.parseLong (objResult.getString("next_cursor"));
ListViewLoaderTask listViewLoaderTask = new ListViewLoaderTask();
listViewLoaderTask.execute(jsonResult);
} catch (JSONException e) {
e.printStackTrace();
}
}
#Override
public void failure(Exception e) {
}
});
return null;
}
#Override
protected void onPostExecute(Void result) {
}
}
Lastly when we load more data i call listViewLoaderTask again for binding retrieved data from service.
It works but there some problems. When reminder data comes(5 row) dialog box become smaller.And sometimes when i click text view it isn't opened dialog box.
Question 1: How can i make my dialog box stable. is Custom dialog efficiency solution for this.
Question 2: I used async methods for this operations. Do you think that my usage right ? What best practice way do you advice for my this task ?
Related
Hello i'm new to android studio and i have code which is showing recycler view list from json data. Now i want to open items in new activity.I want to open item from recyclerview and show image and some text in new activity. I need solution code.
I have tried some ways but it doesn't work.
This is my code:
public class MainActivity extends AppCompatActivity {
public static final int CONNECTION_TIMEOUT = 10000;
public static final int READ_TIMEOUT = 15000;
private RecyclerView mRVFishPrice;
private AdapterFish mAdapter;
SwipeRefreshLayout mSwipeRefreshLayout;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mSwipeRefreshLayout = (SwipeRefreshLayout)findViewById(R.id.swifeRefresh);
mSwipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
#Override
public void onRefresh() {
new AsyncFetch().execute();
}
});
new AsyncFetch().execute();
}
private class AsyncFetch extends AsyncTask<String, String, String> {
ProgressDialog pdLoading = new ProgressDialog(MainActivity.this);
HttpURLConnection conn;
URL url = null;
#Override
protected void onPreExecute() {
super.onPreExecute();
//this method will be running on UI thread
pdLoading.setMessage("\tLoading...");
pdLoading.setCancelable(false);
pdLoading.show();
}
#Override
protected String doInBackground(String... params) {
try {
url = new URL("https://MYURL.com");
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
return e.toString();
}
try {
// Setup HttpURLConnection class to send and receive data from php and mysql
conn = (HttpURLConnection) url.openConnection();
conn.setReadTimeout(READ_TIMEOUT);
conn.setConnectTimeout(CONNECTION_TIMEOUT);
conn.setRequestMethod("GET");
// setDoOutput to true as we recieve data from json file
conn.setDoOutput(true);
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
return e1.toString();
}
try {
int response_code = conn.getResponseCode();
// Check if successful connection made
if (response_code == HttpURLConnection.HTTP_OK) {
// Read data sent from server
InputStream input = conn.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(input));
StringBuilder result = new StringBuilder();
String line;
while ((line = reader.readLine()) != null) {
result.append(line);
}
// Pass data to onPostExecute method
return (result.toString());
} else {
return ("unsuccessful");
}
} catch (IOException e) {
e.printStackTrace();
return e.toString();
} finally {
conn.disconnect();
}
}
#Override
protected void onPostExecute(String result) {
//this method will be running on UI thread
mSwipeRefreshLayout.setRefreshing(false);
pdLoading.dismiss();
List<DataFish> data=new ArrayList<>();
pdLoading.dismiss();
try {
JSONArray jArray = new JSONArray(result);
for(int i=0;i<jArray.length();i++){
JSONObject json_data = jArray.getJSONObject(i);
DataFish fishData = new DataFish();
fishData.fishImage= json_data.getString("fish_img");
fishData.fishName= json_data.getString("fish_name");
fishData.catName= json_data.getString("cat_name");
fishData.sizeName= json_data.getString("size_name");
fishData.price= json_data.getInt("price");
data.add(fishData);
}
mRVFishPrice = (RecyclerView)findViewById(R.id.fishPriceList);
mAdapter = new AdapterFish(MainActivity.this, data);
mRVFishPrice.setAdapter(mAdapter);
mRVFishPrice.setLayoutManager(new LinearLayoutManager(MainActivity.this));
} catch (JSONException e) {
Toast.makeText(MainActivity.this, e.toString(), Toast.LENGTH_LONG).show();
}
}
}
}
I expect to open item from recyclerview list in new activity and show image item and some text.
You can archive this by passing an instance of the interface in your adapter class and implement that interface in your activity.
refer this to get insights link
Sample Snippets
Declare interface:
public interface AdapterCallback {
void onFishClick(DataFish item);
}
Pass interface instance via setup your adapter in activity.
new AdapterFish(MainActivity.this, data, new AdapterCallback() {
#Override
void onfishClick(DataFish item) {
// herer do your work
}
});
In your adapter constructor
private AdapterCallback callback;
AdapterFish(Context contex, data, AdapterCallback callback) {
...
this.callback = callback;
}
define click listener in a holder and inside a method call callback.onFishCall(selectedItem);
OnBindViewHolder(...) {
holder.button.onClicklistener(new OnClickListener{
...
if(callback != null) { // for null check
callback.onFishClikc(item);
}
});
}
I am implementing endless listview in Fragment. When I writes the code for setOnScrollListener for my listview then my app is crashing with the error The content of the adapter has changed but ListView did not receive a notification. Make sure the content of your adapter is not modified from a background thread, but only from the UI thread. Make sure your adapter calls notifyDataSetChanged() when its content changes. I have tried almost everything to apply notifyDataSetChanged() on my adapter. Please help me to solve the problem.
below is my code.
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View rootView = inflater.inflate(R.layout.fragment_all_campaign, container, false);
allCampaignList = (ListView) rootView.findViewById(R.id.allCampaignList);
adapter = new CampaignListAdapter(getActivity(), CampaignDataArrayList);
loadCampaignsData(offsetValue);
allCampaignList.setOnScrollListener(new AbsListView.OnScrollListener() {
#Override
public void onScroll(AbsListView view,
int firstVisibleItem, int visibleItemCount,
int totalItemCount) {
//Algorithm to check if the last item is visible or not
final int lastItem = firstVisibleItem + visibleItemCount;
if (lastItem == totalItemCount) {
// you have reached end of list, load more data
loadCampaignsData(offsetValue + 1);
offsetValue++;
}
}
#Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
//blank, not using this
}
});
return rootView;
}
Below is the method loadCampaignsData():
public void loadCampaignsData(final int offset) {
pDialog.setMessage("Please wait..");
pDialog.setTitle("Loading");
showDialog();
Handler h = new Handler() {
#Override
public void handleMessage(Message msg) {
if (msg.what != 1) {
hideDialog();// code if not connected
viewUtils.internertErrorMsgDialog();
} else {
GetAllCampaign getAllCampaign = new GetAllCampaign();
getAllCampaign.execute(String.valueOf(offset));
}
}
};
viewUtils.isNetworkAvailable(h, 2000); // get the answser within 2000 ms
}
Below is the asynctask written for fetching webservice.
private class GetAllCampaign extends AsyncTask<String, Void, ArrayList<HashMap<String, String>>> {
#Override
protected ArrayList<HashMap<String, String>> doInBackground(String... params) {
try {
HttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(Constants.DADAMI_URL + Constants.ALL_CAMPAIGN);
List<NameValuePair> list = new ArrayList<NameValuePair>();
list.add(new BasicNameValuePair("cat_id", "0"));
list.add(new BasicNameValuePair("user_id", ""));
list.add(new BasicNameValuePair("offset", params[0]));
httpPost.setEntity(new UrlEncodedFormEntity(list));
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
return readResponse(httpResponse);
//return null;
} catch (Exception exception) {
exception.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(ArrayList<HashMap<String, String>> result) {
super.onPostExecute(result);
hideDialog();
if (result == null) {
Toast.makeText(context, "Something went wrong.. Please try again..!!", Toast.LENGTH_LONG).show();
} else {
getActivity().runOnUiThread(new Runnable() {
public void run() {
allCampaignList.setAdapter(adapter);
}
});
}
}
}
private ArrayList<HashMap<String, String>> readResponse(HttpResponse res) {
InputStream is = null;
try {
is = res.getEntity().getContent();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(is));
StringBuffer sb = new StringBuffer();
String line = "";
while ((line = bufferedReader.readLine()) != null) {
sb.append(line);
}
JSONObject mainObj = new JSONObject(sb.toString());
JSONArray fundraiser_data = null;
fundraiser_data = mainObj.getJSONArray("fundraiser_data");
for (int i = 0; i < fundraiser_data.length(); i++) {
JSONObject elem = fundraiser_data.getJSONObject(i);
String fundraiser_photo = elem.getString("fundraiser_photo");
String title = elem.getString("title");
String fullname = elem.getString("fullname");
HashMap<String, String> campaignData = new HashMap<>();
campaignData.put("fundraiser_photo", Constants.DADAMI_IMAGE_URL + fundraiser_photo);
campaignData.put("title", title);
campaignData.put("fullname", fullname);
CampaignDataArrayList.add(campaignData);
}
} catch (Exception e) {
e.printStackTrace();
}
return CampaignDataArrayList;
}
I'm having a hard time figuring out how to implement the new MyAsyncTask().execute("") that I've searched because I have separate classes that extends Asynctask. I wanted to call the class everytime i click the button. Hope you guys can help me figure this out.
Here is my MainActivity
public class MainActivity extends AppCompatActivity {
String url = "http://192.168.254.103/dbtest/categories.php";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button button = (Button) findViewById(R.id.start);
final ListView lv = (ListView) findViewById(R.id.lv);
final Downloader d = new Downloader(this,url,lv);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
d.execute();
}
});
}
}
Here is my Downloader.java
public class Downloader extends AsyncTask<Void,Integer, String> {
Context c;
String address;
ListView lv;
ProgressDialog pd;
public Downloader(Context c, String address, ListView lv) {
this.c = c;
this.address = address;
this.lv = lv;
}
//BEFORE JOB STARTS
#Override
protected void onPreExecute() {
super.onPreExecute();
pd = new ProgressDialog(c);
pd.setTitle("Fetch Data");
pd.setMessage("Please Wait");
pd.show();
}
#Override
protected String doInBackground(Void... params) {
String data = downloadData();
return data;
}
#Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
pd.dismiss();
if(s != null){
Parser p =new Parser(c,s,lv);
p.execute();
}else
{
Toast.makeText(c,"Unable to download data",Toast.LENGTH_SHORT).show();
}
}
private String downloadData(){
//connect and get a stream
InputStream is = null;
String line = null;
try{
URL url = new URL(address);
HttpURLConnection con = (HttpURLConnection) url.openConnection();
is = new BufferedInputStream(con.getInputStream());
BufferedReader br = new BufferedReader(new InputStreamReader(is));
StringBuffer sb = new StringBuffer();
if(br != null){
while((line = br.readLine()) != null)
{
sb.append(line+"\n");
}
}
else
{
return null;
}
return sb.toString();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}finally {
if(is != null){
try {
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return null;
}
}
and my Parser.java
public class Parser extends AsyncTask<Void,Integer,Integer> {
Context c;
ListView lv;
String data;
ArrayList<String> categories = new ArrayList<>();
ProgressDialog pd;
public Parser(Context c, String data, ListView lv) {
this.c = c;
this.data = data;
this.lv = lv;
}
#Override
protected void onPreExecute() {
super.onPreExecute();
pd = new ProgressDialog(c);
pd.setTitle("Parser");
pd.setMessage("Please Wait");
pd.show();
}
#Override
protected Integer doInBackground(Void... params) {
return this.parse();
}
#Override
protected void onPostExecute(Integer integer) {
super.onPostExecute(integer);
if(integer == 1)
{
//ADAPTER
ArrayAdapter<String> adapter = new ArrayAdapter<String>(c, android.R.layout.simple_list_item_1, categories);
lv.setAdapter(adapter);
lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
}
});
}else
{
Toast.makeText(c,"Unable to Parse",Toast.LENGTH_SHORT).show();
}
pd.dismiss();
}
//PARSE RECEIVED DATA
private int parse(){
try
{
//ADD TGAT DATA TO JSON ARRAY FIRST
JSONArray ja = new JSONArray(data);
//CREATE JO OBJECT TO HOLD A SINGLE ITEM
JSONObject jo = null;
categories.clear();
//LOOP THROUGH ARRAY
for(int i =0 ; i<ja.length();i++)
{
jo = ja.getJSONObject(i);
//RETRIEVE NAME
String name=jo.getString("cat_name");
//ADD TO ARRAY LIST
categories.add(name);
}
return 1;
} catch (JSONException e) {
e.printStackTrace();
}
return 0;
}
}
I tried the code below and also tried the AsyncTaskLoader approach. The app crashes when I instantiate the AsyncTask. Pleas advise me on the best approach to load JSON in a list fragment inside tab host.
The code below is the tab fragment (I use action bar tabs in main activity):
public class TabTop extends ListFragment {
Context context = getActivity().getBaseContext();
String API_URL = "http://api.rottentomatoes.com/api/public/v1.0/movies/770672122/similar.json?apikey=crhhxb4accwwa6cy6fxrm8vj&limit=1";
ArrayList<Deal> deals;
DealsListAdapter adapter;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
#SuppressWarnings("unused")
int a = 0;
return super.onCreateView(inflater, container, savedInstanceState);
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
GetTopDeals getTopDeals = new GetTopDeals(context);
getTopDeals.execute(API_URL);
super.onActivityCreated(savedInstanceState);
}
class GetTopDeals extends AsyncTask<String, Void, ArrayList<Deal>>{
ProgressDialog progressDialog;
public GetTopDeals(Context activity) {
this.progressDialog = new ProgressDialog(activity);
}
#Override
protected void onPostExecute(ArrayList<Deal> result) {
adapter = new DealsListAdapter(context, result);
setListAdapter(adapter);
super.onPostExecute(result);
}
#Override
protected void onPreExecute() {
progressDialog.setCancelable(true);
progressDialog.setProgress(0);
progressDialog.setMessage("loading Top deals...");
progressDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
super.onPreExecute();
}
#Override
protected ArrayList<Deal> doInBackground(String... urls) {
String response = sendRequest(urls[0]); // make request for json
return processResponse(response); // parse the Json and return ArrayList to postExecute
}
private String sendRequest(String apiUrl) {
BufferedReader input = null; // get the json
HttpURLConnection httpCon = null; // the http connection object
StringBuilder response = new StringBuilder(); // hold all the data from the jason in string separated with "\n"
try {
URL url = new URL(apiUrl);
httpCon = (HttpURLConnection) url.openConnection();
if (httpCon.getResponseCode() != HttpURLConnection.HTTP_OK) { // check for connectivity with server
return null;
}
input = new BufferedReader(new InputStreamReader(httpCon.getInputStream())); // pull all the json from the site
String line;
while ((line = input.readLine()) != null) {
response.append(line + "\n");
}
} catch (Exception e) {
e.printStackTrace();
} finally {
if (input != null) {
try {
input.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if (httpCon != null) {
httpCon.disconnect();
}
}
return response.toString();
}
}
public ArrayList<Deal> processResponse(String response) {
try {
JSONObject responseObject = new JSONObject(response); // Creates a new JSONObject with name/value mappings from the JSON string.
JSONArray results = responseObject.getJSONArray("movies"); // Returns the value mapped by name if it exists and is a JSONArray.
deals = new ArrayList<Deal>();
for (int i = 0; i < results.length(); i++) { // in this loop i copy the json array to movies arraylist in order to display listView
JSONObject jMovie = results.getJSONObject(i);
int api_id = jMovie.getInt("id");
String name = jMovie.getString("title");
String content = jMovie.getString("synopsis");
JSONObject posters = jMovie.getJSONObject("posters");
String image_url = posters.getString("profile");
}
}catch (JSONException e) {
e.printStackTrace();
}
return deals;
}
#Override
public void onStart() {
super.onStart();
}
#Override
public void onListItemClick(ListView l, View v, int position, long id) {
Intent intent = new Intent(getActivity().getBaseContext(), DealInformation.class);
startActivity(intent);
super.onListItemClick(l, v, position, id);
}
}
Make your asynctask in his own file.
And when your asynctask is finish, implement OnPostExecute which is automatically call. Notify your adapter by a notifyDataSetChanged like that :
#Override
protected void onPostExecute(List<NewItem> list) {
Adapter.getListe().clear();
Adapter.getListe().addAll(list);
Adapter.notifyDataSetChanged();
}
thank you guys,
i want to post my answer. after some research i decided to go with AsyncTaskLoader.
this is my code
public class TabOurPicks extends ListFragment implements LoaderCallbacks<String[]> {
// when activity loads- onActivityCreated() calls the initLoader() who activate onCreateLoader()
#Override
public void onActivityCreated(Bundle savedInstance) {
super.onActivityCreated(savedInstance);
setListAdapter(new ArrayAdapter<String>(getActivity(), android.R.layout.simple_list_item_1, new String[]{}));
getLoaderManager().initLoader(0, null,this).forceLoad();
}
// onCreateLoader instantiate the asynctaskloaser who work in bg
#Override
public RSSLoader onCreateLoader(int arg0, Bundle arg1) {
return new RSSLoader(getActivity()); //
}
// after bg process invoke onLoadFinished() who work in ui thread
#Override
public void onLoadFinished(Loader<String[]> loader, String[] data) {
setListAdapter(new ArrayAdapter<String>(getActivity(), android.R.layout.simple_list_item_1, data
) );
}
#Override
public void onLoaderReset(Loader<String[]> arg0) {
// TODO Auto-generated method stub
}
and this is the inner class for the loader:
static public class RSSLoader extends AsyncTaskLoader<String[]>
{
public RSSLoader(Context context) {
super(context);
}
#Override
public String[] loadInBackground() {
String url = "http://api.rottentomatoes.com/api/public/v1.0/movies/770672122/similar.json?apikey=crhhxb4accwwa6cy6fxrm8vj&limit=1";
String response = sendRequest(url);
return processResponse(response);
}
private String sendRequest(String url) {
BufferedReader input = null; // get the json
HttpURLConnection httpCon = null; // the http connection object
StringBuilder response = new StringBuilder(); // hold all the data from the jason in string separated with "\n"
try {
URL apiUrl = new URL(url);
httpCon = (HttpURLConnection) apiUrl.openConnection();
if (httpCon.getResponseCode() != HttpURLConnection.HTTP_OK) { // check for connectivity with server
return null;
}
input = new BufferedReader(new InputStreamReader(httpCon.getInputStream())); // pull all the json from the site
String line;
while ((line = input.readLine()) != null) {
response.append(line + "\n");
}
} catch (Exception e) {
e.printStackTrace();
} finally {
if (input != null) {
try {
input.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if (httpCon != null) {
httpCon.disconnect();
}
}
return response.toString();
}
private String[] processResponse(String response) {
String[] deals = null;
try {
JSONObject responseObject = new JSONObject(response); // Creates a new JSONObject with name/value mappings from the JSON string.
JSONArray results = responseObject.getJSONArray("movies"); // Returns the value mapped by name if it exists and is a JSONArray.
deals = new String[10];
for (int i = 0; i < 9; i++) { // in this loop i copy the json array to movies arraylist in order to display listView
JSONObject jMovie = results.getJSONObject(i);
String name = jMovie.getString("title");
deals[i] = name;
}
}catch (JSONException e) {
e.printStackTrace();
}
return deals;
}
}
}
It doesn't matter if your asynctask has its own file. You just don't want your activity to extends asynctask as this would make your activity asynchronous - but this is impossible to do anyways due to java's double inheritance rule.
Based on the architecture of your app and your programming style the asyntask can be an inner class in the activity. on the PostExecute method make sure you have given data to your adapter and that the adapter is set to the list, then just run notifyDataSetChanged().
Assuming your asynctask is loading data from cache or the network you are on the right track with your approach to this.
This is my Activity class where i use AsyncTask to get data from a server:
public class UserProfileActivity extends Activity {
private ImageView userImage;
private TextView userName;
private TextView userLocation;
private TextView editInfo;
private TextView chnageImage;
private TextView userScore;
private ListView friendsList;
public ArrayAdapter<String> adapter;
public int score;
public int level;
public String image;
public String fname;
public String lname;
public String city;
public int id;
public String email;
protected Activity activity = this;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.user_profile);
userImage = (ImageView) findViewById(R.id.profileImage);
userName = (TextView) findViewById(R.id.userName_profile);
userLocation = (TextView) findViewById(R.id.userLocation_profile);
editInfo = (TextView) findViewById(R.id.edit_profile);
chnageImage = (TextView) findViewById(R.id.changeImage_profile);
userScore = (TextView) findViewById(R.id.userScore_profile);
friendsList = (ListView) findViewById(R.id.friendsList);
new LongOperation().execute("");
}
private class LongOperation extends AsyncTask<String, Void, String> {
private InputStream is;
private StringBuilder sb;
private String result;
#Override
protected String doInBackground(String... params) {
try {
HttpPost httppost = new HttpPost(
"http://www.xxxxxxxxx.com/mobile/getProfileInfo");
HttpResponse response = SignUpActivity.httpclient
.execute(httppost);
HttpEntity entity = response.getEntity();
is = entity.getContent();
try {
BufferedReader reader = new BufferedReader(
new InputStreamReader(is, "iso-8859-1"), 8);
sb = new StringBuilder();
sb.append(reader.readLine() + "\n");
String line = "0";
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
result = sb.toString();
} catch (Exception e) {
}
try {
JSONObject jObj = new JSONObject(result);
String status = jObj.getString("status");
score = jObj.getInt("credits");
level = jObj.getInt("level");
image = jObj.getString("image");
fname = jObj.getString("fname");
lname = jObj.getString("lname");
city = jObj.getString("city");
id = jObj.getInt("user_id");
email = jObj.getString("email");
JSONArray friendsJsonArray = jObj.getJSONArray("friends");
int size = friendsJsonArray.length();
ArrayList<String> friendsNames = new ArrayList<String>();
String[] friendsIds = new String[size];
for (int i = 0; i < size; i++) {
friendsNames.add(friendsJsonArray.getJSONObject(i)
.getString("name"));
}
adapter = new ArrayAdapter<String>(getApplicationContext(),
R.layout.simple_listview_item, friendsNames);
} catch (Exception e) {
}
} catch (Exception e) {
}
return "Executed";
}
#Override
protected void onPostExecute(String result) {
friendsList.setAdapter(adapter);
userScore.setText(score + " points" + " level " + level);
userName.setText(fname + " " + lname);
userLocation.setText(city);
Bitmap bitmap = null;
try {
bitmap = BitmapFactory
.decodeStream((InputStream) new URL(image).getContent());
} catch (MalformedURLException e1) {
e1.printStackTrace();
} catch (IOException e2) {
e2.printStackTrace();
}
userImage.setImageBitmap(bitmap);
}
#Override
protected void onPreExecute() {
}
#Override
protected void onProgressUpdate(Void... values) {
}
}
}
when this activity is loaded it shows all the default values and images and then changes when background code execution is competed(as excepted), but this takes 2-3 secs for which user will be seeing default values, which i dont want to. So how can i keep a spinner like this:
for 2-3 secs and then when the spinner disappears the activity must show the actual values.
Thank you
Refer the below code
private class FetchRSSFeeds extends AsyncTask<String, Void, Boolean> {
private ProgressDialog dialog = new ProgressDialog(HomeActivity.this);
/** progress dialog to show user that the backup is processing. */
/** application context. */
#Override
protected void onPreExecute() {
this.dialog.setMessage("Please wait");
this.dialog.show();
}
#Override
protected Boolean doInBackground(final String... args) {
try {
Utilities.arrayRSS = objRSSFeed
.FetchRSSFeeds(Constants.Feed_URL);
return true;
} catch (Exception e) {
Log.e("tag", "error", e);
return false;
}
}
#Override
protected void onPostExecute(final Boolean success) {
if (dialog.isShowing()) {
dialog.dismiss();
}
// Setting data to list adapter
setListData();
}
Do This:-
Declare the ProgressDialog at the Top.
ProgressDialog pd;
Start it in onPreExecute Method of Async Task.
pd=ProgressDialog.show(ActivityName.this,"","Please Wait",false);
Stop it in the onPostExecute Method.
pd.dismiss();
In onCreate method call some like below
mdialog=new Dialog(this);
new LongOperation().execute("");
Then override onPostExecute of AyncTask
#Override
protected void onPostExecute() {
runOnUiThread(new Runnable() {
#Override
public void run() {
// TODO Auto-generated method stub
mdialog.dismiss();
}
});
}