NumberToMatch.java

public class TestSum {


    public static void main(String[] args) {
        List<Integer> inputNumbers = new ArrayList<Integer>();
        inputNumbers.add(3);
        inputNumbers.add(4);
        inputNumbers.add(6);
        inputNumbers.add(2);
        inputNumbers.add(5);
        inputNumbers.add(1);
        inputNumbers.add(7);
        inputNumbers.add(1);
        List<List<Integer>> result = new ArrayList<>();

        Object[] inputArray = inputNumbers.toArray();
        int size = inputNumbers.size();

        int numberToMatch = 7;
        int counter = -1;
        for (Object item : inputArray) {
            int number = (int) item;
            counter++;
            List<Integer> matched = new ArrayList<>();

            if (number == numberToMatch) {
                matched.add(number);
            } else if (number < numberToMatch) {
                matched = findSumResult(Arrays.copyOfRange(inputArray, counter + 1, size), numberToMatch, number);
            }

            if (matched != null && !matched.isEmpty()) {

                result.add(matched);
            }
        }
        System.out.println(result);
    }

    public static List<Integer> findSumResult(Object[] subArray, int numberToMatch, int currentValue) {
        int sum = currentValue;
        List<Integer> result = new ArrayList<>();
        result.add(currentValue);
        for (Object i : subArray) {
            int number = (int) i;
            if (sum < numberToMatch && sum + number <= numberToMatch) {
                sum += number;
                result.add(number);
            }

        }
        return sum == numberToMatch ? result : null;
    }

}