Answers for "java convert list to integer array"

list to int array in java 8

int[] array = list.stream().mapToInt(i->i).toArray();

convert list of integer to array in java

List<Integer> al = new ArrayList<Integer>(); 
Integer[] arr = new Integer[al.size()]; 
arr = al.toArray(arr);

how to convert int array to Integer List in java

int[] ints = {1,2,3};
List<Integer> list = Arrays.stream(ints).boxed().collect(Collectors.toList());