I have to upload data to a server. I am using a service that is running on the same process as my application. Should I use a Separate thread for upload process or Should I use a AsyncTask to upload data to server ?
More specifically can I use AsyncTask inside a service class ? And should I use it ? This service should always be running in memory in order to send data to the server every 5 seconds.
Yes you can, the below code will run every 5 seconds. Use your regular connection code for sending part.
public class AsyncTaskInServiceService extends Service {
public AsyncTaskInServiceService() {
super("AsyncTaskInServiceService ");
}
@Override
public void onCreate() {
// TODO Auto-generated method stub
super.onCreate();
}
@Override
protected void onHandleIntent(Intent intent) {
final Timer t = new Timer();
t.scheduleAtFixedRate(new TimerTask() {
@Override
public void run() {
//Connect to database here
try {
} catch (JSONException e) {
e.printStackTrace();
}
}
}, 0, 5000);
}
}
No problem to use AsyncTask in a service.
NOTE / FIX : I was wrong when I said the service runs in background, it only applis to IntentService. As noted in the comments and in the documentation, a service does not create it's own thread :
Caution: A service runs in the main thread of its hosting process—the service does not create its own thread and does not run in a separate process (unless you specify otherwise). This means that, if your service is going to do any CPU intensive work or blocking operations (such as MP3 playback or networking), you should create a new thread within the service to do that work.
That means you must use an AsyncTask (or another thread in any case) to perform your upload task.
Use AsyncTask in a service in android
package com.emergingandroidtech.Services;
import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.util.Log;
import android.widget.Toast;
import java.net.MalformedURLException;
import java.net.URL;
import android.os.AsyncTask;
public class MyService extends Service
{
@Override
public IBinder onBind(Intent arg0)
{
return null;
}
@Override
public int onStartCommand(Intent intent,int flags,int startId)
{
//We want this service to continue running until it is explicitly
//stopped,so return sticky.
Toast.makeText(this,“ServiceStarted”,Toast.LENGTH_LONG).show();
try
{
new DoBackgroundTask().execute(
new URL(“http://www.google.com/somefiles.pdf”),
new URL(“http://emergingandroidtech.blogspot.in”));
}
catch (MalformedURLException e)
{
e.printStackTrace();
}
return START_STICKY;
}
@Override
public void onDestroy()
{
super.onDestroy();
Toast.makeText(this,“ServiceDestroyed”,Toast.LENGTH_LONG).show();
}
private int DownloadFile(URL url)
{
try
{
//---simulate taking sometime to download a file---
Thread.sleep(5000);
}
catch(InterruptedException e)
{
e.printStackTrace();
}
//---return an arbitrary number representing
//the size of the file downloaded---
return 100;
}
private class DoBackgroundTask extends AsyncTask<URL, Integer, Long>
{
protected Long doInBackground(URL... urls)
{
int count = urls.length;
long totalBytesDownloaded = 0;
for (int i = 0; i < count; i++)
{
totalBytesDownloaded += DownloadFile(urls[i]);
//---calculate percentage downloaded and
// report its progress---
publishProgress((int) (((i+1) / (float) count) * 100));
}
return totalBytesDownloaded;
}
protected void onProgressUpdate(Integer... progress)
{
Log.d(“Downloading files”, String.valueOf(progress[0]) + “% downloaded”);
Toast.makeText(getBaseContext(), String.valueOf(progress[0]) + “% downloaded”, Toast.LENGTH_LONG).show();
}
protected void onPostExecute(Long result)
{
Toast.makeText(getBaseContext(), “Downloaded “ + result + “ bytes”, Toast.LENGTH_LONG).show();
stopSelf();
}
}
}
Try this it may be work. Thank you.
来源：https://stackoverflow.com/questions/22043652/using-an-asynctask-inside-a-service-class