by using java program

. Write a recursive method that for a positive integer returns a string with commas in the appropriate places, for example, putcommas (1234567) returns the string "1,234,567". ITk 9. Write a recursive method to add the first n terms of the series 1 + For a given character recursively, a. Check if it is in a string. b. Count all of its occurrences in a string. c. Remove all of its occurrences from a string. 16