java - Call ASyncTask for notification -

i want use asynctask on app sending notification user when on website, json value =\= false.

the asynctask as:

public class asynctask extends asynctask<string, void, string> {    private static boolean onair;   public static final string tag = "[notif]";    private final static int interval = 1000; //2 minutes   handler mhandler = new handler();    private final httpclient httpclient = new defaulthttpclient();   final httpparams params = httpclient.getparams();   httpresponse response;   private string content =  null;   private boolean error = false;    private context mcontext;   private int notification_id = 1;   private notification mnotification;   private notificationmanager mnotificationmanager;    runnable mhandlertask = new runnable() {     @override     public void run() {       detectonline_prepare();       mhandler.postdelayed(mhandlertask, interval);     }   };    public asynctask(context context){     this.mcontext = context;      //get notification manager     mnotificationmanager = (notificationmanager) mcontext.getsystemservice(context.notification_service);    }    protected void onpreexecute() {     log.i(tag, "erreur onpretexecute");   }    protected string doinbackground(string... urls) {      detectonline_prepare();     return content;   }    protected void oncancelled() {     createnotification("une erreur s'est produite",content);   }    protected void onpostexecute(string content) {     detectonline_prepare();     if (error) {       log.i(tag, "erreur onpostexecute");     } else {       log.i(tag, "[notif] ok");       createnotification("ok","ok");     }   }    private void createnotification(string contenttitle, string contenttext) {      //build notification using notification.builder     notification.builder builder = new notification.builder(mcontext)                 .setsmallicon(android.r.drawable.stat_sys_download)                 .setautocancel(true)                 .setcontenttitle(contenttitle)                 .setcontenttext(contenttext);      //get current notification     mnotification = builder.getnotification();      //show notification     mnotificationmanager.notify(notification_id, mnotification);   }    public void detectonline_prepare(){     strictmode.threadpolicy policy = new strictmode.threadpolicy.builder().permitall().build();     strictmode.setthreadpolicy(policy);     try {       detectonline();     } catch (jsonexception | ioexception e) {       e.printstacktrace(system.out);     }   }    public void detectonline() throws jsonexception, ioexception {     strictmode.threadpolicy policy = new strictmode.threadpolicy.builder().permitall().build();     strictmode.setthreadpolicy(policy);     checkifonline();      if (onair == false) {       log.i(tag, "variable off");     } else {       //createnotification();       log.i(tag, "variable on");     }   }    public static void checkifonline() throws jsonexception, ioexception {     strictmode.threadpolicy policy = new strictmode.threadpolicy.builder().permitall().build();     strictmode.setthreadpolicy(policy);      string channerurl = "https://api.dailymotion.com/video/x3p6d9r?fields=onair";      string jsontext = readfromurl(channerurl);// reads text url      jsonobject json = new jsonobject(jsontext); // create json object string jsontext     if (json.has("onair")) { // simple test check node need existe       //boolean onair = json.getboolean("onair"); // in url gave onair value boolean type       onair = json.getboolean("onair");       return;     }  }   private static string readfromurl(string url) throws ioexception {    strictmode.threadpolicy policy = new strictmode.threadpolicy.builder().permitall().build();    strictmode.setthreadpolicy(policy);    url page = new url(url);    stringbuilder sb = new stringbuilder();    scanner scanner = null;    try {      scanner = new scanner(page.openstream());      while (scanner.hasnextline()) {        sb.append(scanner.nextline());      }    } {      if (scanner != null)         scanner.close();    }    return sb.tostring(); } 

but want know how work. how can call mainactivity asynctask (for work in background).

thank you

asyntask threads let operations in separate thread (non-ui main thread). don't need asyntask notifications, can achieved using pendingintent , listeners phone call, touch listener, etc.

now coming question try this:

in main thread following:

asynstask myasynctask = new asynctask(getapplicationcontext()); myasynctask.execute(); 

tutorial: good read