( please the answer have to me in JAVA only and please provide explanation to each method)

Solve the following problems in Java. You may write all of the methods in the same class. All methods must be recursive. You may not use any loops. You must moo like a cow if you get the StackOverflowError. You must cluck like a chicken if you get the ArrayIndexOutOfBoundsException. Problem 2: Write a recursive method that computes the sum of a given array of integers. public static int sum(int[] a) f return sum(a, 0): private static int sum(int[] a, int i) [ // WRITE ME! Problem 1: Write a recursive method that returns the index of a given element in a given array (do not assume the elements are in order) Problem 3: Write a recursive method that finds the largest integer in a given array of integers. Problem 4: Write a recursive method that prints a given string backwards. Remember that you can use the charAt method to use a string as a character array. The only other String method you may use is length