the Problem I am having is that the PostExecute is not firing.
I see the log tag for background but P.E. never fires.
I am invoking this task from a timer like this:
findViewById(R.id.buttonstart).setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
try {
openFile("FeedTimerTask.html");
Timer t = new Timer("FeedTimerTask", true);
timerTask = new FeedTimerTask();
t.schedule(timerTask, 2000, 20000);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
});
Runnable runme = new Runnable() {
#Override
public void run() {
timestart = Calendar.getInstance().getTimeInMillis();
provider.refreshNoCache();
}
};
class FeedTimerTask extends TimerTask{
#Override
public void run() {
try{Looper.prepare();}catch(Exception e){};
runme.run();
}
}
Here is the main task itself from inside the dataprovider class invoked with "provider.refreshNoCache();" above:
// threaded rteftesh tasks
#SuppressWarnings("rawtypes")
public class RefreshTask extends SupportAsyncTask {
private int errorcodecode = 0;
private ProgressDialog dialog=null;
private Exception mainExeption=null;
protected String waitMessage = "Laddar ner information..";
private boolean useCache;
public RefreshTask(boolean useCache) {
this.useCache = useCache;
}
public void onPreExecute() {
data = null;
if (showSpinnerOnRefresh){
dialog = ProgressDialog.show(context, "", waitMessage , true);
dialog.show();
}
}
protected Object doInBackground(Object... params) {
errorcodecode = 1;
try {
invokeFeedRead();
Log.e("DataProvider", "Bkgtask...");
errorcodecode = 0;
} catch (BrJSONException e) {
Log.e("[ERROR]","PROVIDER "+e.getMessage());
mainExeption = e;
errorcodecode = 1;
} catch (IOException e) {
Log.e("[ERROR]","PROVIDER "+e.getMessage());
mainExeption = e;
errorcodecode = 2;
} catch (Exception e) {
Log.e("[ERROR]","PROVIDER "+e.getMessage());
mainExeption = e;
errorcodecode = 3;
}
if (errorcodecode==0){
}
return null;
}
#Override
protected void onCancelled() {
super.onCancelled();
Log.e("DataProvider", "Cancelled...");
if (dialog != null)
try{dialog.dismiss();}catch(Exception e){}
BrAlert.Show(context, "Obs", BrAppConfig.ServerError+" (timeout)", 0);
onError_IO(new IOException("Timeout!"));
errorcodecode=2;
}
#Override
protected void onPostExecute(Object result) {
// super.onPostExecute(result);
Log.e("DataProvider", "PostExec...");
if (dialog != null)
try{dialog.dismiss();}catch(Exception e){}
switch (errorcodecode) {
case 0:
onFeedLoaded();
cacheAge = System.currentTimeMillis();
break;
case 1:
onError_DataFormat(mainExeption);
break;
case 2:
onError_IO(mainExeption);
break;
default:
onError_GeneralExeption(mainExeption);
}
}
}
Your task is cancelled even before it reached onPostExecte method. If the task is cancelled before it reaches onPostExecute Method. It will not trigger onPostExecute but trigger onCancelled Method. Please provide enough time to finish the task.
I found out the problem in the end. It was to do with the scope.
I needed a handler to invoke the other thread.
Here is the solution for others may find helpful:
in on create:
tickHandler = new Handler();
tickTimer = new Timer();
tickTimer.schedule(new FeedTimerTask(),
0,
50000); //FPS
The handler class.
class FeedTimerTask extends TimerTask{
private Runnable runable;
public FeedTimerTask(){
super();
runable = new Runnable(){
#Override
public void run() {
timestart = Calendar.getInstance().getTimeInMillis();
provider.refreshNoCache();
}
};
}
#Override
public void run() {
tickHandler.post(runable);
}
}
Related
In my App my I am using AlertDialog in Async. But it freezes at a point when data is saving in database. what can I do to keep it running? It runs perfectly for sometime but stops after certain time when database is accessed.
Here's my code:
class BackGroundTasks extends AsyncTask<String, String, Void> {
#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
CheckInternetConnection internet = new CheckInternetConnection(
mActivity);
if (!internet.HaveNetworkConnection()) {
return null;
}
return null;
}
protected void onPostExecute(Void result) {
super.onPostExecute(result);
try {
CheckInternetConnection internet = new CheckInternetConnection(
getApplicationContext());
if (!internet.HaveNetworkConnection()) {
showToast("No Internet Connection.");
return;
} else {
setUpdatedBarcodes();
}
}
}
}
private boolean setUpdatedBarcodes(
ArrayList<Model_BarcodeDetail> changedBarcodeList2) {
try {
int i = 0;
BarcodeDatabase barcodeDatabase = new
BarcodeDatabase(mActivity);
barcodeDatabase.open();
for (Model_BarcodeDetail model : changedBarcodeList2) {
barcodeDatabase.updateEntry(model, userId);
}
barcodeDatabase.close();
if (RefList1.equals(RefList)) {
if (dialog != null) {
dialog.dismiss(); // cancelling Async dialog here after
data is saved in DB
}
showToast("Barcodes updated successfully");
}
} catch (Exception e) {
Log.i("Exception caught in: ", "setDownloadedBarcodes method");
e.printStackTrace();
return false;
}
return true;
}
DB operations should be done in the background thread. Put it in doInBackground() method too.
I modify your code. may it helps..
class BackGroundTasks extends AsyncTask<String, String, Void> {
#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
CheckInternetConnection internet = new CheckInternetConnection(
mActivity);
if (!internet.HaveNetworkConnection()) {
showToast("No Internet Connection.");
} else {
setUpdatedBarcodes();
}
return null;
}
protected void onPostExecute(Void result) {
super.onPostExecute(result);
if (dialog != null) {
dialog.dismiss(); // cancelling Async dialog here
}
}
}
private boolean setUpdatedBarcodes(
ArrayList<Model_BarcodeDetail> changedBarcodeList2) {
try {
int i = 0;
BarcodeDatabase barcodeDatabase = new
BarcodeDatabase(mActivity);
barcodeDatabase.open();
for (Model_BarcodeDetail model : changedBarcodeList2) {
barcodeDatabase.updateEntry(model, userId);
}
barcodeDatabase.close();
if (RefList1.equals(RefList)) {
showToast("Barcodes updated successfully");
}
} catch (Exception e) {
Log.i("Exception caught in: ", "setDownloadedBarcodes method");
e.printStackTrace();
return false;
}
return true;
}
when saving data in database don't do it on main thread do it on background thread. try code
new Handler().postDelayed(new Runnable() {
#Override
public void run() {
// do your work
}
},0);
or
new Thread(new Runnable() {
public void run() {
// do your work here
}
}).start();
thread = new Thread(new Runnable() {
#Override
public void run() {
synchronized (datahandler) {
while (true) {
try {
if (datahandler.getCount() > 0) {
commitData();
}
datahandler.wait();
} catch (InterruptedException e) {
e.printStackTrace();
Log.e("Service", e.toString());
}
}
}
}
});
thread.start();
Commitdata to connect and commit data form datahandler to server. But I dont kow why it shows not respone dialog. If I do not close it, it continouns to commit. Why UI is influenced when I commit data in other thread
public class ThreadsLifecycleActivity extends Activity {
// Static so that the thread access the latest attribute
private static ProgressDialog dialog;
private static Bitmap downloadBitmap;
private static Handler handler;
private ImageView imageView;
private Thread downloadThread;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
// create a handler to update the UI
handler = new Handler() {
#Override
public void handleMessage(Message msg) {
imageView.setImageBitmap(downloadBitmap);
dialog.dismiss();
}
};
// get the latest imageView after restart of the application
imageView = (ImageView) findViewById(R.id.imageView1);
Context context = imageView.getContext();
System.out.println(context);
// Did we already download the image?
if (downloadBitmap != null) {
imageView.setImageBitmap(downloadBitmap);
}
// check if the thread is already running
downloadThread = (Thread) getLastNonConfigurationInstance();
if (downloadThread != null && downloadThread.isAlive()) {
dialog = ProgressDialog.show(this, "Download", "downloading");
}
}
public void downloadPicture(View view) {
dialog = ProgressDialog.show(this, "Download", "downloading");
downloadThread = new MyThread();
downloadThread.start();
}
// save the thread
#Override
public Object onRetainNonConfigurationInstance() {
return downloadThread;
}
// dismiss dialog if activity is destroyed
#Override
protected void onDestroy() {
if (dialog != null && dialog.isShowing()) {
dialog.dismiss();
dialog = null;
}
super.onDestroy();
}
static public class MyThread extends Thread {
#Override
public void run() {
try {
// Simulate a slow network
try {
new Thread().sleep(5000);
} catch (InterruptedException e) {
e.printStackTrace();
}
downloadBitmap = downloadBitmap("http://www.devoxx.com/download/attachments/4751369/DV11");
// Updates the user interface
handler.sendEmptyMessage(0);
} catch (IOException e) {
e.printStackTrace();
} finally {
}
}
}
}
//==========================
You can sea in code that handlers are used to post message on GUI thread. further you can read about it over here
http://www.vogella.com/tutorials/AndroidBackgroundProcessing/article.html
Also Read This http://android-developers.blogspot.de/2010/07/multithreading-for-performance.html
My splash screen syncronize my app :
When I use :
sd.execute("init_sync", null).get();
My logo (defined in xml) disappear. If I quit .get(), it appears.
Here is my code :
public class SplashScreen extends Activity {
private Context ctx = null;
private Usuario mUser = null;
SharedPreferences prefs;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.splash);
ctx = this;
prefs = PreferenceManager.getDefaultSharedPreferences(this);
new Handler().post(new Runnable() {
#Override
public void run() {
// Check if user exists
Gson gson = new Gson();
String jsonUser = prefs.getString("usuario", "");
mUser = gson.fromJson(jsonUser, Usuario.class);
if (NetworkUtils.isOnline(ctx)) {
if (mUser != null) {
SyncData sd = new SyncData(ctx);
try {
sd.execute("init_sync", null).get();
} catch (InterruptedException e) {
e.printStackTrace();
} catch (ExecutionException e) {
e.printStackTrace();
}
} else {
Intent i = new Intent(SplashScreen.this, LoginActivity.class);
startActivity(i);
}
} else {
if (mUser != null) {
Intent i = new Intent(SplashScreen.this, DashBoard.class);
startActivity(i);
} else {
Toast.makeText(ctx, "Necesita Internet para loguearse", Toast.LENGTH_LONG).show();
finish();
}
}
}
});
}
}
I have several asyncTask that I use to upload pics, and sync MySQL database with my SQLite database. So, I need to wait till all the processes end to know if there is any error.
The thing is I put it in a thread, so that it would not affect UI. Where am I wrong?
When you use get() it causes the UI thread to wait. Don't use get(). You need to override the onPostExecute method in AsyncTask.
private Boolean task1Finished = false;
private Boolean task2Finished = false;
private Boolean task3Finished = false;
//...
SyncData sd1 = new SyncData(ctx) {
#Override
protected void onPostExecute(Object result) {
task1Finished = true;
goToNextActivity();
}
};
SyncData sd2 = new SyncData(ctx) {
#Override
protected void onPostExecute(Object result) {
task2Finished = true;
goToNextActivity();
}
};
SyncData sd3 = new SyncData(ctx) {
#Override
protected void onPostExecute(Object result) {
task3Finished = true;
goToNextActivity();
}
};
try {
sd1.execute();
sd2.execute();
sd3.execute();
}
catch (InterruptedException e) {
e.printStackTrace();
}
catch (ExecutionException e) {
e.printStackTrace();
}
//...
private void goToNextActivity() {
if (task1Finished && task2Finished && task3Finished)
// all tasks complete
}
Like #ashishduh says, I was in UI Thread. So I changed:
new Handler().post(new Runnable() {
#Override
public void run() {
....
}
}
by
Runnable sync = new Runnable() {
#Override
public void run() {
....
}
};
Thread t = new Thread(sync);
t.start();
And it solved my problem!
please see the codes:
MainActivity.java:
protected void onCreate(Bundle savedInstanceState) {
...
TestClass tc = new TestClass();
tc.Test(new TestListener() {
public void onSuccess() {
//success do something
}
public void onFail() {
//fail do something
}
});
}
TestClass:
public class TestClass {
private static final int MSG_SUCCESS = 1;
private static final int MSG_FAIL = 0;
private TestListener listener = null;
public void Test(TestListener listener) {
this.listener = listener;
Log.d("test", "=======" + Thread.currentThread().getId());
HandlerThread ht = new HandlerThread("MyThread");
ht.start();
Thread thread = new Thread(mRunnable);
thread.run();
}
#SuppressLint("HandlerLeak")
private Handler mHandler = new Handler() {
#Override
public void handleMessage(Message msg) {
switch (msg.what) {
case MSG_SUCCESS:
Log.d("test", "on success");
if (listener != null) {
listener.onSuccess();
}
break;
case MSG_FAIL:
if (listener != null) {
listener.onFail();
}
break;
}
}
};
Runnable mRunnable = new Runnable() {
#Override
public void run() {
Log.d("test", "=======" + Thread.currentThread().getId());
try {
Log.d("test", "start sleep");
Thread.sleep(10000);
} catch (InterruptedException e) {
e.printStackTrace();
}
Log.d("test", "sleep end");
mHandler.obtainMessage(MSG_SUCCESS).sendToTarget();
}
};
}
TestListener:
public interface TestListener {
public void onSuccess();
public void onFail();
}
print log:
07-30 15:15:03.565: D/test(2202): =======1
07-30 15:15:03.565: D/test(2202): =======1
Slaver Thread have no effect？？
This is the problem:
thread.run();
That's running the Runnable code synchronously, in the existing thread. You meant:
thread.start();
first of all you will have to show() your Toast msgs:
Toast.makeText(getApplicationContext(), "onsuccess", Toast.LENGTH_SHORT).show();
and you want to start() your thread:
thread.start();
I have a service which contains a Timer and TimerTask for receiving data from Webservice in periods of time. When my TimerTask runs, the UI hangs until the Webservice process complete. How can I put my task in a thread to prevent the UI hanging?
My code:
Timer timerSyncFull = new Timer();
class taskSyncFull extends TimerTask {
#Override
public void run() {
hSyncFull.sendEmptyMessage(0);
}
};
final Handler hSyncFull = new Handler(new Callback() {
#Override
public boolean handleMessage(Message msg) {
procSyncFull();
return false;
}
});
public void procSyncFull() {
try {
// My webservice process
} catch (Exception e) {
}
}
#Override
public void onStart(Intent intent, int startId) {
timerSyncFull = new Timer();
timerSyncFull.schedule(new taskSyncFull(), 5*60*1000,
5*60*1000);
}
Use AsyncTasks or attach your Handler to another Looper thread.
I used the following code and my problem solved:
class taskSendMapMovements extends TimerTask {
#Override
public void run() {
hhSendMapMovements.sendEmptyMessage(0);
}
};
// /////////////////////
final Runnable rSendMapMovements = new Runnable()
{
public void run()
{
procSendMapMovements();
}
};
final Handler hhSendMapMovements = new Handler(new Callback() {
#Override
public boolean handleMessage(Message msg) {
performOnBackgroundThread(rSendMapMovements);
return false;
}
});
// /////////////////////
public void procSendMapMovements() {
try {
showToast("some text");
//My Main Process
} catch (Exception e) {
}
}
#Override
public void onStart(Intent intent, int startId) {
try {
timerSendMapMovements = new Timer();
timerSendMapMovements
.schedule(new taskSendMapMovements(),
10*60*1000,
10*60*1000);
//
} catch (NumberFormatException e) {
Toast.makeText(this, "error running service: " + e.getMessage(),
Toast.LENGTH_SHORT).show();
} catch (Exception e) {
Toast.makeText(this, "error running service: " + e.getMessage(),
Toast.LENGTH_SHORT).show();
}
}
final Handler hToast = new Handler(new Callback() {
#Override
public boolean handleMessage(Message msg) {
Toast.makeText(SrvDataExchange.this,
msg.getData().getString("msg"),
Toast.LENGTH_LONG).show();
return false;
}
});
private void showToast(String strMessage) {
Message msg = new Message();
Bundle b = new Bundle();
b.putString("msg", strMessage);
msg.setData(b);
hToast.sendMessage(msg);
}
public static Thread performOnBackgroundThread(final Runnable runnable) {
final Thread t = new Thread() {
#Override
public void run() {
try {
runnable.run();
} finally {
}
}
};
t.start();
return t;
}
Simply invoke your procSyncFull() method in thread or asyncTask.
final Handler hSyncFull = new Handler(new Callback() {
#Override
public boolean handleMessage(Message msg) {
Thread thread=new Thread()
{
public void run(){
procSyncFull();
}
}
return false;
}
});
private Handler webserviceCompletionHandler=new Handler()
{
#Override
public boolean handleMessage(Message msg) {
return false;
}
};
use AsyncTask carry out your execution in doInBackground() and populate it in onPostExecute()
AsyncTask Example