How to use ExecutorService of java concurrent programming?

Question

Iam using below code for uploading images on the remote server.When I use below it is uploading all images cocurrently on remote server.

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Answer 1

When you call singleFuture.get() you are waiting for the operation to complete. So the loop won't continue to execute next statement until this one returns a result.

You need to submit your tasks in the first loop and after that, another loop should iterate over the results future.get() on your list to make it async

From @andersoj's answer;

The Pool size should be something related to your CPU cores. Not the number of images you have in hand. Say if you have 2 cored CPU, a coefficient of 5 (just my guess of coefficient) for image uploading io time.

POOL_SIZE = NUM_OF_CPU_CORE*coeffiecient;