ON JAVA! pls

thank you

and returns an array of all excluding the empty .) should return an cat" (in any order). (a) Write and test a method that takes a String and retu its substrings (including the whole string but excluding string). For example, allSubstrings ("cat") should array with values "C", "a", "t", "ca", "at", "cat" (in any Hint: If n is the length of the string, the number of substring n(n+1) 2 (b)' Using the method from Part (a), write and test a method that take array of strings words and returns a two-dimensional array in which the k-th row is the array of all substrings of words [k]. Hint: String[] [] s = new String[n] []; declares a 2-D array of strings with n rows," where each row is undefined (set to null)