Solution

public static int[] getUniqueArray(int numbers[]){
        ArrayList<Integer> tmp = new ArrayList<>();

        for (int i=0; i<numbers.length; i++){
            if(!tmp.contains(numbers[i])){
                tmp.add(numbers[i]);
            }
        }

        int[] ret = new int[tmp.size()];
        for (int i=0; i < ret.length; i++)
        {
            ret[i] = tmp.get(i).intValue();
        }

        return ret;
    }

    public static void main(String[] args)
    {
        int[] X = {1,1,1,2,3,3,4};
        int[] Output = getUniqueArray(X);
        for(int i=0;i<Output.length;i++){
            System.out.println(Output[i]);
        }

    }