Peek throw com.google.gson.JsonSyntaxException

[thedamfr]

Hey !

Sometimes, in production, I will get something wrong and an object will be stuck. The Queue is going to throw a com.google.gson.JsonSyntaxException each time this object is peek()

Do you have any idea why ?

For now, all I can do is ask the user to clear data cache, but some datas are lost each time.

Thanks !

[thedamfr]

Defensive code here ! Not sexy

But here is a sneak peak of how to get defensive about this :

 } catch (JsonSyntaxException jsonSyntaxException) {
            // Crap
            try {
                // Use refexivity to get the unparsable string
                Field delegateField = InventoryTaskQueue.class.getDeclaredField("delegate");
                delegateField.setAccessible(true);
                FileObjectQueue delegateValue = (FileObjectQueue) delegateField.get(queue);
                Field queueFileField = FileObjectQueue.class.getDeclaredField("queueFile");
                queueFileField.setAccessible(true);
                QueueFile queueFileValue = (QueueFile) delegateField.get(delegateValue);
                byte[] bytes = queueFileValue.peek();

                // Put that shit in Crashlytics
                Crashlytics.setString("Problematic JSON", new String(bytes));

                // Also Reflexivity is a very dangerous way of life. Catch them all
            } catch (NoSuchFieldException e) {
                e.printStackTrace();
                Crashlytics.logException(e);
            } catch (IOException e) {
                e.printStackTrace();
                Crashlytics.logException(e);
            } catch (IllegalAccessException e) {
                e.printStackTrace();
                Crashlytics.logException(e);
            }
            // Log exception to Crashlytics
            Crashlytics.logException(jsonSyntaxException);

            // Remove that stuck shit
            queue.remove();

        }

[thedamfr]

Okay. Real life aka. Production shows that queue.remove() send a NoSuchElement exception in that case.

[sergiopantoja]

@thedamfr Ah! I'm glad I'm not alone on this one. I encounter the same exact errors in production: I've seen the queue get stuck several times, and I've also seen the NoSuchElement exception on queue.remove().

I was able to debug the queue one time when it was stuck. queue.peek() was returning NULL, but queue.size() was > 0. Didn't have enough time to dig deeper unfortunately.

[ragunathjawahar]

+1, happens with protocol buffers as well while peeking.

java.net.ProtocolException: Unexpected tag 0

[JakeWharton]

Are you peeking on a different thread than writing?