Object not locked by thread before notify() in onPostExecute

Asked 5 years, 4 months ago

Viewed 56k time

I try to notify adapters of listviews of main class in onPostExecute but I receive the error: java.lang.IllegalMonitorStateException:object not locked by thread before notify()

@Override
protected void onPostExecute(String result) {
    popularfragment.adapter.notifyDataSetChanged();
    recentfragment.adapter.notifyDataSetChanged();
}

asked Jun 12 '14 at 13:38

Erkan Erol

65411 gold badge77 silver badges2323 bronze badges

add a comment

2 Answers

active oldest votes

The .notify() method has to be called from within a synchronized context, ie from inside a synchronized block.

The java.lang.IllegalMonitorStateException is thrown when you call .notify() on an object that is not used as the lock for the synchronized block in which you call notify. For example, the following works;

synchronized(obj){
    obj.notify();
}

But this will throw the exception;

synchronized(obj){
    // notify() is being called here when the thread and 
    // synchronized block does not own the lock on the object.
    anotherObj.notify();        
}

Reference;

edited May 23 '17 at 11:55

Community♦

111 silver badge

answered Jun 12 '14 at 13:48

Rudi Kershaw

7,72555 gold badges3838 silver badges6969 bronze badges

add a comment

I had the same error, but (for me) the answer suggested by Rudi Kershaw wasn't the issue... I called the notify() of a Notification the wrong way (see the last line of both snippets):

Not working:

public void update() {
    mBuilder.setSmallIcon(R.drawable.ic_launcher)
            .setPriority(AesPrefs.getInt(R.string.PRIORITY_NOTIFICATION_BATTERY, NotificationCompat.PRIORITY_MAX))
            .setOngoing(true);
    mBuilder.setWhen(AesPrefs.getLong(Loader.gStr(R.string.LAST_FIRED_BATTERY_NOTIFICATION) + Const.START_CLIPBOARD_NOTIFICATION_DELAYED, -1));
    mManager.notify(); // <- lil' mistake
}

Working:

public void update() {
    mBuilder.setSmallIcon(R.drawable.ic_launcher)
            .setPriority(AesPrefs.getInt(R.string.PRIORITY_NOTIFICATION_BATTERY, NotificationCompat.PRIORITY_MAX))
            .setOngoing(true);
    mBuilder.setWhen(AesPrefs.getLong(Loader.gStr(R.string.LAST_FIRED_BATTERY_NOTIFICATION) + Const.START_CLIPBOARD_NOTIFICATION_DELAYED, -1));
    mManager.notify(Const.NOTIFICATION_CLIPBOARD, mBuilder.build()); // <- ok ;-)
}

answered Dec 29 '15 at 20:19

Martin Pfeffer

8,59877 gold badges4444 silver badges6060 bronze badges

add a comment

https://stackoverflow.com/questions/24185921/object-not-locked-by-thread-before-notify-in-onpostexecute