I wrote myself a utility to break a list into batches of given size. I just wanted to know if there is already any apache commons util for this.
public static <T> List<List<T>> getBatches(List<T> collection,int batchSize){
int i = 0;
List<List<T>> batches = new ArrayList<List<T>>();
while(i<collection.size()){
int nextInc = Math.min(collection.size()-i,batchSize);
List<T> batch = collection.subList(i,i+nextInc);
batches.add(batch);
i = i + nextInc;
}
return batches;
}
Please let me know if there any existing utility already for the same.
Check out Lists.partition(java.util.List, int)
from Google Guava:
Returns consecutive sublists of a list, each of the same size (the final list may be smaller). For example, partitioning a list containing
[a, b, c, d, e]
with a partition size of 3 yields[[a, b, c]
,[d, e]]
-- an outer list containing two inner lists of three and two elements, all in the original order.