there are times even the application is requesting for parallel processing, it could stick to one single thread without rotation.

for example, the case,

this could be the case…

however, when trying to group the elements by thread, below code is not always working

most of the time, it would equally divided the elements into…

similar to circuit breaker, spring retry is a mechanism to handle for intermittent service unavailability and fallback if that has been sustained.

my code has been working well

it would log the error several times before either it return a true when the data is available or return false after 10 tries.


when the forked out thread is running the task, if any exception happens, depends on the mechanism how the thread/threadpool is constructed, it could handle the exception differently.

for forkjoinpool, if the task is executed. when the task failed with exception, it will propagate the exception, till it’s either handled or if uncaught then captured by the `UncaughtExceptionHandler`. (this is called by JVM).

when the task is submitted though, the task is wrapped into AdaptedRunnableAction, which doesn't propagate the exception.

I think what JCP/JVM trying to do is, trust the developers know the difference between the call and handle the…

when i am running the preparedstatement with setString(index,value), it's throwing index out of range. even though the index is correct, 1 with 1 parameter.

turns out the cause is, java…

turns out when serialization for Enum, instead of customizing the serializer to customize the output, it’s possible to annotate the method or field with @JsonValue.

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