How do i input an array to a Map Reduce Job?

How do i input an array to a Map Reduce Job?

I have a service that is continuously retrieving some data .I am dumping
this data into an array, this data has to be further processed. Is it
possible to create a dynamic array that keeps getting updated by serivice,
and side by side i can execute the Map Reduce Job? Also how what class do
i use to simply take an array input(instead of a file) ? PS I'm new to
Hadoop/Map Reduce I'm coding in Java.