Java8 programming, convert pseudo-code to actual java code(method) and using a main method(public static void main(String[] args) to test the method

Problem 4. Given an array A consisting of n integers A [O], A[1],...,A(n-1), we want to compute the upper triangle matrix CATA_A[i] + A[i+1] + ... + Alil j-i +1 for 0