Develop Reference

Showing ProgressBar on parsing and downloading json result

In my App I am hitting a service which can have no result to n number of results(basically some barcodes). As of now I am using default circular progressbar when json is parsed and result is being saved in local DB(using sqlite). But if the json has large number of data it sometimes takes 30-45 min to parse and simultaneously saving that data in DB, which makes the interface unresponsive for that period of time and that makes user think the app has broken/hanged. For this problem I want to show a progressbar with the percentage stating how much data is parsed and saved so that user get to know the App is still working and not dead. I took help from this link but couldn't find how to achieve. Here's my Asynctask,
class BackGroundTasks extends AsyncTask<String, String, Void> {
private String operation, itemRef;
private ArrayList<Model_BarcodeDetail> changedBarcodeList, barcodeList;
private ArrayList<String> changeRefList;
String page;
public BackGroundTasks(String operation, String itemRef, String page) {
this.operation = operation;
this.itemRef = itemRef;
this.page = page;
}
#Override
protected void onPreExecute() {
// TODO Auto-generated method stub
super.onPreExecute();
if (dialog == null) {
dialog = ProgressDialog.show(mActivity, null,
"Please wait ...", true);
}
}
#Override
protected Void doInBackground(String... params) {
// TODO Auto-generated method stub
try{
if (!connection.HaveNetworkConnection()) {
dialog.dismiss();
connection.showToast(screenSize, "No Internet Connection.");
return null;
}
if (operation.equalsIgnoreCase("DownloadChangeItemRef")) {
changeRefList = DownloadChangeItemRef(params[1]);
if (changeRefList != null && !changeRefList.isEmpty()) {
RefList1.addAll(changeRefList);
}
}
if ((changeRefList != null && changeRefList.size() >0)) {
setUpdatedBarcodes(changedBarcodeList);
}
}
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
#SuppressLint("SimpleDateFormat")
#Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
}
}
ArrayList<String> DownloadChangeItemRef(String api_token) {
ArrayList<String> changedRefList = null;
HttpClient httpClient = new DefaultHttpClient();
HttpPost postRequest = new HttpPost(thoth_url + "/" + todaysDate
+ "?&return=json");
String url = thoth_url + "/" + todaysDate + "?&return=json";
String result = "";
try {
changedRefList = new ArrayList<String>();
ResponseHandler<String> responseHandler = new BasicResponseHandler();
result = httpClient.execute(postRequest, responseHandler);
JSONObject jsonObj = new JSONObject(result);
JSONArray jsonarray = jsonObj.getJSONArray("changes");
if (jsonarray.length() == 0) {
return null;
}
for (int i = 0; i < jsonarray.length(); i++) {
JSONObject obj = jsonarray.getJSONObject(i);
changedRefList.add(obj.getString("ref"));
}
} catch (IllegalStateException e) {
// TODO Auto-generated catch block
// when there is no thoth url
Log.i("inclient: ", e.getMessage());
return null;
} catch (Exception e) {
// when there are no itemref
return null;
}
return changedRefList;
}
private boolean setUpdatedBarcodes(
final ArrayList<Model_BarcodeDetail> changedBarcodeList2) {
try {
BarcodeDatabase barcodeDatabase = new BarcodeDatabase(mActivity);
barcodeDatabase.open();
for (Model_BarcodeDetail model : changedBarcodeList2) {
barcodeDatabase.updateEntry(model, userId);
}
n++;
barcodeDatabase.close();
if (RefList1.equals(RefList)) {
if (dialog != null) {
dialog.dismiss();
}
connection.showToast(screenSize, "Barcodes updated successfully");
}
} catch (Exception e) {
Log.i("Exception caught in: ", "setDownloadedBarcodes method");
e.printStackTrace();
return false;
}
return true;
}

Progress Bar not visible with Stand alone asynctask

I am trying to fetch some data from Web Server through JSON. I am using asynctask to do so. Normally it is taking 5-10 seconds to be shown in my ListView.
Hence I want to put spinner progress bar. My code is working fine only problem is the progress bar is not visible.
MyActivity code to call asyntask
try{
JSONObject output = new AsyncTaskJsonParse(this,status, A, B, city).execute().get();
try {
JSONObject output = new AsyncTaskJsonParse(ListViewDisplay.this,status, bgrp, antigen, city).execute().get();
JSONObject src = output.getJSONObject("data");
String flag = output.getString("success");
String flagmsg = output.getString("message");
if (flag == "1") {
JSONArray jarr_name = new JSONArray(src.getString("name"));
JSONArray jarr_fathername = new JSONArray(src.getString("fathername"));
JSONArray jarr_moh = new JSONArray(src.getString("moh"));
JSONArray jarr_city = new JSONArray(src.getString("city"));
JSONArray jarr_phone = new JSONArray(src.getString("phone"));
int n = jarr_name.length();
name_array = new String[n];
fathername_array = new String[n];
moh_array = new String[n];
phone_array = new String[n];
city_array = new String[n];
for (int i = 0; i < n; i++) {
name_array[i] = (String) jarr_name.get(i);
fathername_array[i] = (String) jarr_fathername.get(i);
moh_array[i] = (String) jarr_moh.get(i);
phone_array[i] = (String) jarr_phone.get(i);
city_array[i] = "Vadodara";
Log.d("Inside StringArray", i + "");
}
String msg = src.getString("name");
list = (ListView) findViewById(R.id.listView);
CustomListAdapter custAdaptor = new CustomListAdapter(this, name_array, fathername_array, mohalla_array, city_array, phone_array);
list.setAdapter(custAdaptor);
}else
{
Toast.makeText(this, "Data not found" + flagmsg, Toast.LENGTH_LONG).show();
}
}catch(ExecutionException e){
// TODO Auto-generated catch block
e.printStackTrace();
}
catch(InterruptedException e)
{
e.printStackTrace();
}catch(JSONException je)
{
}
Standalone asyntask with progressbar code
public class AsyncTaskJsonParse extends AsyncTask<String, String, JSONObject>
{
String A,B;
private String url = "abc.com/check.php";
List<NameValuePair> param=new ArrayList<NameValuePair>();
private Context context;
private ProgressDialog progress;
public AsyncTaskJsonParse(Context context,String A,String B,String antigen,String city)
{
this.A=A;
this.B=B;
this.city=city;
this.context=context;
progress=new ProgressDialog(context);
}
#Override
protected void onPreExecute() {
super.onPreExecute();
Log.e("In preexecution ", "Preexecution 1");
progress.setMessage("Processing...");
progress.setIndeterminate(true);
progress.setProgressStyle(ProgressDialog.STYLE_SPINNER);
progress.setCancelable(true);
Log.e("In preexecution azam", "Preexecution 2");
progress.show();
if(progress.isShowing())
{
Log.d("In preexecution ", "Showing 2");
}
}
//rest of code i.e. doInBackground and postexecute come after this.
#Override
protected JSONObject doInBackground(String... arg0) {
// TODO Auto-generated method stub
try
{
JsonParsor parse=new JsonParsor();
Log.d("diInbackgrnd ","Dialog box");
jsonobj = parse.getJSONFromUrl(url, param);
}
catch(Exception e)
{
Log.e(TAG, " "+e );
}
return jsonobj;
}
#Override
protected void onPostExecute(JSONObject result) {
// TODO Auto-generated method stub
super.onPostExecute(result);
//pDialog.dismiss();
if(progress.isShowing())
{
Log.e("In onPost ", "Showing 2");
}
progress.dismiss();
}
}
In my log I can see the message "In preexecution Showing 2". And the appliaction is working as expected but the Spinner progressbar is not visible.
Note: I did not add any progressbar component in any xml file. Does i need to add it? if yes then where and how?
class JsonParser.java
public class JsonParsor {
final String TAG = "JsonParser.java";
static InputStream is = null;
static JSONObject jObj = null;
static String str = "";
public JSONObject getJSONFromUrl(String url,List<NameValuePair> params) {
try {
HttpClient client = new DefaultHttpClient();
HttpPost post = new HttpPost(url);
post.setEntity(new UrlEncodedFormEntity(params));
HttpResponse response = client.execute(post);
HttpEntity entity = response.getEntity();
is = entity.getContent();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
try
{
BufferedReader br=new BufferedReader(new InputStreamReader(is,"iso-8859-1"), 8);
StringBuilder builder=new StringBuilder();
String line=null;
while((line=br.readLine())!=null)
{
builder.append(line + "\n");
}
is.close();
str=builder.toString();
}
catch(Exception e)
{
}
try {
jObj=new JSONObject(str);
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return jObj;
}
}

I suspect your problem is that your AsyncTask finishes immediately as parse.getJSONFromUrl... is also Async. So whats happening is that progress.dismiss(); in onPostExecute invoked also immediately.
Try removing progress.dismiss(); from onPostExecute and see what happens

This should work. But without the progress.setMessage("Processing...");
You can still set that.
#Override
protected void onPreExecute() {
super.onPreExecute();
dialog = new ProgressDialog(getActivity(),R.style.MyTheme);
dialog.setCancelable(false);
dialog.setProgressStyle(android.R.style.Widget_ProgressBar_Small);
dialog.show();
}

Can't properly change my LinearLayout to ListView

Here is ,my code for selecting images and texts from mysql database through php.And it is displaying in a linearlayout in a scrollview.All i want to do is change my layout to listview like this example.
I tried listview and other many ways but its not working properly.I'm new in android,so im trying for a long time.Please help me by editing my code for my requirement.Please.
JAVA
#SuppressLint("NewApi")
public class News_and_events extends Fragment {
private String jsonResult;
private String url = "http://192.168.2.7/crescentnews/select.php";
HttpPost httppost;
StringBuffer buffer;
HttpResponse response;
HttpClient httpclient;
List<NameValuePair> nameValuePairs;
ProgressDialog dialog = null;
ImageView img;
Bitmap bitmap;
ProgressDialog pDialog;
// alert dialog manager
AlertDialogManager alert = new AlertDialogManager();
// Internet detector
ConnectionDetector cd;
InputStream is=null;
String result=null;
String line=null;
int code;
public News_and_events(){}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
pDialog = new ProgressDialog(getActivity());
View rootView = inflater.inflate(R.layout.activity_news_and_events, container, false);
cd = new ConnectionDetector(rootView.getContext());
// Check if Internet present
if (!cd.isConnectingToInternet()) {
// Internet Connection is not present
alert.showAlertDialog(getActivity(),
"Internet Connection Error",
"Please connect to working Internet connection", false);
// stop executing code by return
//return.rootView;
return rootView;
}
accessWebService();
return rootView;
}
// Async Task to access the web
private class JsonReadTask extends AsyncTask<String, Void, String> {
#Override
protected String doInBackground(String... params) {
List<NameValuePair> nameValuePair = new ArrayList<NameValuePair>(1);
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost(params[0]);
try {
httppost.setEntity(new UrlEncodedFormEntity(nameValuePair));
HttpResponse response = httpclient.execute(httppost);
jsonResult = inputStreamToString(
response.getEntity().getContent()).toString();
}
catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
private StringBuilder inputStreamToString(InputStream is) {
String rLine = "";
StringBuilder answer = new StringBuilder();
BufferedReader rd = new BufferedReader(new InputStreamReader(is));
try {
while ((rLine = rd.readLine()) != null) {
answer.append(rLine);
}
}
catch (IOException e) {
// e.printStackTrace();
Toast.makeText(getActivity().getApplicationContext(),
"Error..." + e.toString(), Toast.LENGTH_LONG).show();
}
return answer;
}
#Override
protected void onPostExecute(String result) {
display();
}
}// end async task
public void accessWebService() {
JsonReadTask task = new JsonReadTask();
// passes values for the urls string array
task.execute(new String[] { url });
}
// build hash set for list view
public void display() {
try {
JSONObject jsonResponse = new JSONObject(jsonResult);
JSONArray jsonMainNode = jsonResponse.optJSONArray("news_details");
LinearLayout MainLL= (LinearLayout)getActivity().findViewById(R.id.newslayout);
//LinearLayout headLN=(LinearLayout)findViewById(R.id.headsection);
for (int i = 0; i < jsonMainNode.length(); i++) {
JSONObject jsonChildNode = jsonMainNode.getJSONObject(i);
final String head = jsonChildNode.optString("title");
final String details = jsonChildNode.optString("text");
final String date = jsonChildNode.optString("date");
final String image = jsonChildNode.optString("img");
//final String time = jsonChildNode.optString("time");
//img = new ImageView(this.getActivity());
//new LoadImage().execute("http://192.168.2.7/crescentnews/images/"+image);
img = new ImageView(this.getActivity());
// Toast.makeText(getActivity(),image, Toast.LENGTH_LONG).show();
LoadImage ldimg=new LoadImage();
ldimg.setImage(img);
ldimg.execute("http://192.168.2.7/crescentnews/images/"+image);
TextView headln = new TextView(this.getActivity());
headln.setText(head); // News Headlines
headln.setTextSize(16);
headln.setTextColor(Color.BLACK);
headln.setGravity(Gravity.CENTER);
headln.setBackgroundColor(Color.parseColor("#ffcd14"));
// headln.setBackgroundResource(R.drawable.menubg);
headln.setPadding(0, 20, 0, 0);
// headln.setHeight(50);
headln.setClickable(true);
TextView dateln = new TextView(this.getActivity());
dateln.setText(date); // News Headlines
dateln.setTextSize(12);
dateln.setTextColor(Color.BLACK);
dateln.setGravity(Gravity.RIGHT);
//dateln.setBackgroundColor(Color.parseColor("#f20056"));
dateln.setBackgroundColor(0x00000000);
dateln.setPadding(0, 0, 10, 10);
dateln.setWidth(100);
dateln.setClickable(true);
View sep=new View(this.getActivity());
sep.setBackgroundColor(Color.parseColor("#252525"));
sep.setMinimumHeight(10);
TextView detailsln = new TextView(this.getActivity());
detailsln.setText(details); // News Details
detailsln.setTextSize(12);
detailsln.setTextColor(Color.BLACK);
detailsln.setGravity(Gravity.CENTER);
detailsln.setPadding(10, 10, 10, 10);
int width = LayoutParams.WRAP_CONTENT;
int height = 200;
LinearLayout.LayoutParams parms = new LinearLayout.LayoutParams(width,height);
img.setLayoutParams(parms);
parms.gravity = Gravity.CENTER;
img.setPaddingRelative (15, 15, 15, 15);
MainLL.addView(headln);
MainLL.addView(dateln);
// MainLL.addView(photo);
MainLL.addView(img);
MainLL.addView(detailsln);
MainLL.addView(sep);
img.setClickable(true);
// img.buildDrawingCache();
// final Bitmap bmap = img.getDrawingCache();
headln.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent intent = new Intent(getActivity().getApplicationContext(),InnerNewsAndEvents.class);
intent.putExtra("head",head.toString());
intent.putExtra("details",details.toString());
intent.putExtra("date",date.toString());
intent.putExtra("image", image);
startActivity(intent);
}
});
dateln.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent intent = new Intent(getActivity().getApplicationContext(),InnerNewsAndEvents.class);
intent.putExtra("head",head.toString());
intent.putExtra("details",details.toString());
intent.putExtra("date",date.toString());
intent.putExtra("image", image);
startActivity(intent);
}
});
img.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent intent = new Intent(getActivity().getApplicationContext(),InnerNewsAndEvents.class);
intent.putExtra("head",head.toString());
intent.putExtra("details",details.toString());
intent.putExtra("date",date.toString());
intent.putExtra("image", image);
startActivity(intent);
}
});
detailsln.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent intent = new Intent(getActivity().getApplicationContext(),InnerNewsAndEvents.class);
intent.putExtra("head",head.toString());
intent.putExtra("details",details.toString());
intent.putExtra("date",date.toString());
intent.putExtra("image", image);
startActivity(intent);
}
});
}
} catch (JSONException e) {
Toast.makeText(getActivity().getApplicationContext(), "Error" + e.toString(),
Toast.LENGTH_SHORT).show();
}
}
private class LoadImage extends AsyncTask<String, String, Bitmap> {
ImageView img;
#Override
protected void onPreExecute() {
super.onPreExecute();
pDialog.setMessage("Loading Image ....");
pDialog.show();
}
public void setImage(ImageView img ){
this.img=img;
}
protected Bitmap doInBackground(String... args) {
try {
bitmap = BitmapFactory.decodeStream((InputStream)new URL(args[0]).openStream());
}
catch (Exception e) { e.printStackTrace(); }
return bitmap;
}
protected void onPostExecute(Bitmap image) {
if(image != null){
img.setImageBitmap(image);
pDialog.dismiss();
}
pDialog.dismiss();
}
}
public static boolean isInternetReachable()
{
try {
//make a URL to a known source
URL url = new URL("http://www.google.com");
//open a connection to that source
HttpURLConnection urlConnect = (HttpURLConnection)url.openConnection();
//trying to retrieve data from the source. If there
//is no connection, this line will fail
Object objData = urlConnect.getContent();
} catch (UnknownHostException e) {
e.printStackTrace();
return false;
}
catch (IOException e) {
e.printStackTrace();
return false;
}
return true;
}
}
XML
<ScrollView
android:id="#+id/scrollView1"
android:layout_width="match_parent"[![enter image description here][1]][1]
(source: codelearn.org)
android:layout_height="wrap_content" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:baselineAligned="false"
>
<LinearLayout
android:id="#+id/newslayout"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:background="#ffffff"
>
</LinearLayout>
</LinearLayout>
</ScrollView>
</LinearLayout>

You cannot call display() from within AsyncTask to display results in listview.
You should follow the following steps
Inside on create, Call AsyncTask to fetch the data from server and populate this into an Array List. While async task is running, make sure you display a progress dialogue so that user cannot do anything in the UI thread.
Inside on create, do initialize your listview.
inside on Post execute of AsyncTask, after you have populated all the elements in the arraylist, call the adapter to populate the listview.
Define an adapter which extends BaseAdapter using which you can populate the listview from the array list.
You may want to check out this link for a similar working example.

How to use multiple AsyncTasks

I'm coding the client side of an Android application which uses sockets. Since I'm new with AsyncTask, I coded something simple to test my understanding. Here is what I have, it seems to be correct:
public class Messaggi extends ActionBarActivity implements OnClickListener {
LinearLayout mLayout;
ScrollView scroll;
EditText writeMessage;
Button send;
Socket connection;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.fragment_messaggi);
mLayout = (LinearLayout) findViewById(R.id.linearVertical);
scroll = (ScrollView) findViewById(R.id.scrollView1);
writeMessage= (EditText)findViewById(R.id.ScriviMessaggio);
send= (Button)findViewById(R.id.invia);
send.setOnClickListener(this);
LavoraDietro asd = new LavoraDietro();
asd.execute();
}
#Override
public void onClick(View v) {
}
private void updateScroll(){
scroll.post(new Runnable() {
#Override
public void run() {
scroll.fullScroll(View.FOCUS_DOWN);
}
});
}
private TextView createNewTextView(String text) {
final LayoutParams lparams = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
final TextView textView = new TextView(this);
textView.setLayoutParams(lparams);
textView.setText("Client: " + text);
return textView;
}
private class LavoraDietro extends AsyncTask<Void, Void, Boolean> {
String mex;
#Override
protected Boolean doInBackground(Void... params){
try {
InetAddress local = InetAddress.getByName("192.168.1.79");
Socket connection= new Socket(local , 7100);
DataOutputStream output = new DataOutputStream(connection.getOutputStream());
output.writeUTF("Client: Server prova");
output.flush();
DataInputStream input = new DataInputStream(connection.getInputStream());
mex= input.readUTF();
} catch (UnknownHostException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
return false;
}catch(Exception e){
e.printStackTrace();
}
return true;
}
#Override
protected void onPostExecute(Boolean result) {
super.onPostExecute(result);
if(result == true){
mLayout.addView(createNewTextView("Sono connesso al server"));
mLayout.addView(createNewTextView("I canali sono aperi.."));
mLayout.addView(createNewTextView(mex));
updateScroll();
}
else{
mLayout.addView(createNewTextView("ERRORE CONNESSIONE AL SERVER "));
updateScroll();
}
}
}
}
When the connection to the server is established, the client sends a test meesage and the server should send the same message to the client, where it is printed.
But my task is to establish the connection immediatly when the app is opened and send a message only when the button "send" is pressed. Is possible to create multiple AsyncTasks and make them work at the same time without crashing the application? If yes, can you please post an example of how can I do this?
EDITED CODE
This is my new code:
public class Messaggi extends ActionBarActivity implements OnClickListener {
LinearLayout mLayout;
ScrollView scroll;
EditText writeMessage;
Button send;
Socket connection;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.fragment_messaggi);
mLayout = (LinearLayout) findViewById(R.id.linearVertical);
scroll = (ScrollView) findViewById(R.id.scrollView1);
writeMessage= (EditText)findViewById(R.id.ScriviMessaggio);
send= (Button)findViewById(R.id.invia);
send.setOnClickListener(this);
LavoraDietro asd = new LavoraDietro();
asd.execute();
}
#Override
public void onClick(View v) {
CliccaInvia asd123 = new CliccaInvia();
asd123.execute(connection);
}
private void updateScroll(){
scroll.post(new Runnable() {
#Override
public void run() {
scroll.fullScroll(View.FOCUS_DOWN);
}
});
}
private TextView createNewTextView(String text) {
final LayoutParams lparams = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
final TextView textView = new TextView(this);
textView.setLayoutParams(lparams);
textView.setText("Client: " + text);
return textView;
}
private class LavoraDietro extends AsyncTask<Void, Void, Socket> {
String mex;
#Override
protected Socket doInBackground(Void... params){
try {
InetAddress local = InetAddress.getByName("192.168.1.79");
connection= new Socket(local , 7100);
DataInputStream input = new DataInputStream(connection.getInputStream());
mex = input.readUTF();
} catch (UnknownHostException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}catch(Exception e){
e.printStackTrace();
}
return connection;
}
#Override
protected void onPostExecute(Socket result) {
super.onPostExecute(result);
if(result != null){
mLayout.addView(createNewTextView("Sono connesso al server"));
mLayout.addView(createNewTextView("I canali sono aperi.."));
mLayout.addView(createNewTextView(mex));
updateScroll();
}
else{
mLayout.addView(createNewTextView("ERRORE CONNESSIONE AL SERVER "));
updateScroll();
}
}
}
private class CliccaInvia extends AsyncTask<Socket, Void, Boolean>{
#Override
protected Boolean doInBackground(Socket... params) {
try {
DataOutputStream output = new DataOutputStream(connection.getOutputStream());
output.writeUTF("Client: Server prova");
output.flush();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
return false
}
return true;
}
#Override
protected void onPostExecute(Boolean result) {
super.onPostExecute(result);
if(result == true){
mLayout.addView(createNewTextView("Message Sent"));
aggiornaScroll();
}
else{
mLayout.addView(createNewTextView("Error sending Mex "));
aggiornaScroll();
}
}
}
But this doesn't work.. :(

Well if you need to spawn a lot of tasks and keep track of them all you could do something like this
List<LavoraDietro> tasks = new ArrayList<LavoraDietro>();
LavoraDietro task = new LavoraDietro();
task.execute;
tasks.add(task);
then in your LavoraDietro in the onPostExecute
tasks.remove(this);
But there is a million different ways you could make connections if you want. I recommend Apache's library. http://hc.apache.org/httpclient-3.x/
Here is an example of how you might make a connection, just call this function from inside the background of your task.
public static InputStream getHTTPRequest(String url, ArrayList<NameValuePair> parameters, ArrayList<NameValuePair> headers)
{
final String TAG = "getHTTPRequest";
HttpGet getRequest = new HttpGet(url);
// attach all and any params
if (parameters != null && parameters.size() > 0)
{
HttpParams params = getRequest.getParams();
for (NameValuePair param : parameters)
{
params.setParameter(param.getName(), param.getValue());
}
getRequest.setParams(params);
}
// attach all and any headers
if (headers != null && headers.size() > 0)
{
for (NameValuePair header : headers)
{
getRequest.addHeader(header.getName(), header.getValue());
}
}
getRequest.addHeader("Content-type", "application/json");
getRequest.addHeader("Accept", "application/json");
DefaultHttpClient client = new DefaultHttpClient();
try
{
HttpResponse getResponse = client.execute(getRequest);
final int statusCode = getResponse.getStatusLine().getStatusCode();
if (statusCode != HttpStatus.SC_OK)
{
Log.d(TAG, "status not ok");
Log.d(TAG, "status = " + Integer.toString(statusCode));
Log.d(TAG, "url = " + getRequest.getURI().toString());
return null;
}
HttpEntity getResponseEntity = getResponse.getEntity();
Log.d(TAG, "returning valid content");
return getResponseEntity.getContent();
} catch (IOException e)
{
Log.d(TAG, "IOException: getRequest.abort");
getRequest.abort();
}
return null;
}

Show data on Listview is duplication

I'm doing a app can update data every 1 minutes, data will from database mysql on server to show on listview of my app android. My problem is when show data the first is ok but when show data the second on listview, data of the first and the second is duplication.Can you help me!
Source code:
public class Hoadon extends Activity {
JSONArray jArray;
String result = null;
InputStream is = null;
StringBuilder sb = null;
ArrayList<String> al = new ArrayList<String>();
ArrayList<String> al1 = new ArrayList<String>();
ArrayList<String> al2 = new ArrayList<String>();
ArrayList<String> al3 = new ArrayList<String>();
ArrayList<String> al1a = new ArrayList<String>();
String date;
String name;
String address;
String url;
String code;
int responseCode;
private String IDinvoice;
private TimerTask mTimerTask;
private Timer t=new Timer();
private final Handler handler=new Handler();
private ListView listview;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.hoadon);
int currentOrientation = getResources().getConfiguration().orientation;
if (currentOrientation == Configuration.ORIENTATION_LANDSCAPE) {
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_SENSOR_PORTRAIT);
}
else {
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_SENSOR_PORTRAIT);
}
try {
URL url = new URL("http://longvansolution.tk/monthlytarget.php");
URLConnection connection = url.openConnection();
connection.setConnectTimeout(2000);
HttpURLConnection httpConnection = (HttpURLConnection) connection;
responseCode = httpConnection.getResponseCode();
} catch (Exception e) {
}
try {
if (isNetworkAvailable() == true
//&& responseCode == HttpURLConnection.HTTP_OK
) {
//new LoadData().execute();
al.clear();
al1.clear();
al2.clear();
al3.clear();
al1a.clear();
doTimerTask();
} else {
AlertDialog.Builder ad = new AlertDialog.Builder(this);
ad.setMessage("No Internet Connection available!!!");
ad.show();
}
} catch (Exception e) {
}
Bundle extras = getIntent().getExtras();
if (extras != null) {
IDinvoice = extras.getString("IDinvoice");
}
}
public void doTimerTask(){
mTimerTask = new TimerTask() {
public void run() {
handler.post(new Runnable() {
public void run() {
new LoadData().execute();
Log.d("TIMER", "TimerTask run");
}
});
}};
// public void schedule (TimerTask task, long delay, long period)
t.schedule(mTimerTask, 500, 10000); //
}
#Override
public void onBackPressed() {
//do something with bitmap
}
private class LoadData extends AsyncTask<Void, Void, Void> {
private ProgressDialog progressDialog;
#Override
// can use UI thread here
protected void onPreExecute() {
this.progressDialog = ProgressDialog.show(
Hoadon.this, "", " Loading...");
}
#Override
protected void onPostExecute(final Void unused) {
this.progressDialog.dismiss();
try {
listview = (ListView) findViewById(R.id.listView1);
this.progressDialog.dismiss();
listview.setAdapter(new DataAdapter(Hoadon.this,
al.toArray(new String[al.size()]), al1a
.toArray(new String[al1a.size()]), al1
.toArray(new String[al1.size()]), al2
.toArray(new String[al2.size()])));
listview.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// TODO Auto-generated method stub
String t = al3.get(position);
Intent i = new Intent(Hoadon.this,
Signature.class);
i.putExtra("url", t);
startActivity(i);
}
});
} catch (Exception e) {
Toast.makeText(getApplicationContext(), e.toString(),
Toast.LENGTH_LONG).show();
}
}
#Override
protected Void doInBackground(Void... params) {
// TODO Auto-generated method stub
// HTTP post
try {
ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
HttpClient httpclient = new DefaultHttpClient();
try {
HttpPost httppost = new HttpPost(
"http://longvansolution.tk/monthlytarget.php");
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
is = entity.getContent();
} catch (Exception e) {
Toast.makeText(getApplicationContext(), e.toString(),
Toast.LENGTH_LONG).show();
}
// buffered reader
try {
BufferedReader reader = new BufferedReader(
new InputStreamReader(is, "iso-8859-1"), 80);
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) {
Toast.makeText(getApplicationContext(), e.toString(),
Toast.LENGTH_LONG).show();
}
try {
jArray = new JSONArray(result);
JSONObject json_data = null;
for (int i = 0; i < jArray.length(); i++) {
json_data = jArray.getJSONObject(i);
date = json_data.getString("date");
address = json_data.getString("address");
name = json_data.getString("name");
url = json_data.getString("url");
code = json_data.getString("code");
al.add(date);
al1a.add(code);
al1.add(name);
al2.add(address);
al3.add(url);
}
} catch (JSONException e) {
Toast.makeText(getApplicationContext(), e.toString(),
Toast.LENGTH_LONG).show();
}
} catch (ParseException e) {
// Log.e("log_tag", "Error in http connection" + e.toString());
Toast.makeText(getApplicationContext(), e.toString(),
Toast.LENGTH_LONG).show();
} catch (Exception e) {
// Log.e("log_tag", "Error in http connection" + e.toString());
Toast.makeText(getApplicationContext(), e.toString(),
Toast.LENGTH_LONG).show();
}
return null;
}
}
public boolean isNetworkAvailable() {
ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo networkInfo = cm.getActiveNetworkInfo();
// if no network is available networkInfo will be null, otherwise check
// if we are connected
if (networkInfo != null && networkInfo.isConnected()) {
// Log.i("net status:", "Online...!!!");
return true;
}
// Log.i("net status:", "offline...!!!");
return false;
}
}
Source DataAdapter
public class DataAdapter extends BaseAdapter {
Context mContext;
private LayoutInflater mInflater;
String[] date;
String[] code;
String[] address;
String[] name;
public DataAdapter(Context c, String[] date,String[] code, String[] name, String[] address) {
this.date = date;
this.code=code;
this.name = name;
this.address = address;
mContext = c;
mInflater = LayoutInflater.from(c);
}
public void clearData() {
// clear the data
Arrays.fill(date, null);
Arrays.fill(code, null);
Arrays.fill(address, null);
Arrays.fill(name, null);
}
public int getCount() {
return date.length;
}
public Object getItem(int position) {
return position;
}
public long getItemId(int position) {
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder = null;
if (convertView == null) {
convertView = mInflater.inflate(R.layout.customgrid, parent, false);
holder = new ViewHolder();
holder.date = (TextView) convertView.findViewById(R.id.date);
holder.code=(TextView)convertView.findViewById(R.id.mahd);
holder.name = (TextView) convertView.findViewById(R.id.name);
holder.address = (TextView) convertView.findViewById(R.id.address);
if (position == 0) {
convertView.setTag(holder);
}
} else {
holder = (ViewHolder) convertView.getTag();
}
try {
holder.date.setText(date[position]);
holder.code.setText(code[position]);
holder.name.setText(name[position]);
holder.address.setText(address[position]);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return convertView;
}
static class ViewHolder {
TextView date,code;
TextView name, address;
}
}

you should clear your arralist every LoadData task.
try {
jArray = new JSONArray(result);
JSONObject json_data = null;
al.clear();
al1.clear();
al2.clear();
al3.clear();
al1a.clear();
for (int i = 0; i < jArray.length(); i++) {
json_data = jArray.getJSONObject(i);
date = json_data.getString("date");
address = json_data.getString("address");
name = json_data.getString("name");
url = json_data.getString("url");
code = json_data.getString("code");
al.add(date);
al1a.add(code);
al1.add(name);
al2.add(address);
al3.add(url);
}