Question

I must use Thread in an Android project. Sometimes, it works corectly, however sometimes does not; it does not start (does not call SendToServer() method)or it starts but return to another function suddenly (return updated; line)before the thread does not finish.

Note: affected value is bigger than 0, it gives condition and it goes to if statement.

Here is the my code sample;

public static Boolean MyUpdateFunction(MyObject myobject){

Boolean updated=false;
//Code for updating local database


int affected= SqliteDb.update(....);

if(affected>0)
{
    //Send updated data to server
    //For this I must use Thread(I can't use AsyncThread)
    updated=true;
    SendToServer();

}


return updated;
}

public static void SendToServer()

{
    try{
        ;
        Thread th=new Thread(new Runnable() {

        public void run() {
            try {

                //Create data and send it to server
                //.......
            } catch (Exception e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    });
    th.start();
    th.join();




}
catch(SQLException e)
{
    Toast.makeText(myContext,"ERROR: "+e.getMessage(), Toast.LENGTH_LONG).show();
} catch (InterruptedException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}
}

Answer 1

Instead of using threads and your variables (updated and affected), you can use AsyncTasks: see: http://developer.android.com/reference/android/os/AsyncTask.html

With AsyncTask, you have some methods which are doing exactly what you want:

• onPreExecute
• doInBackground
• onPostExecute

So, what you can do is to check your condition in onPreExecute, then do your SendToServer in the doInBackground and onPostExecute do what you need.