write a public static method named replaceFirst that takes in a String s and a char c as arguments. The method will return a modified String replacing the first character with the one that was passed in. (Do not print out the String) Special cases: If s is null, the method should return null. If s is the blank string, “”, the method should return the blank string. Example: Replace.replaceFirst(“make”, ‘t’); Returns: “take” Replace.replaceFirst(“a”, ‘x’); Returns: “x” Java tests: Test replaceFirst(null, char c) replaceFirst("", char c)keyboard_arrow_up replaceFirst(String s, char c)Unit testkeyboard_arrow_down

(Intro to Java) Pls answer asap Write Answers Neatly Thanks

JAVA PPROGRAM ASAP   Please create  this program ASAP BECAUSE IT IS MY LAB ASSIGNMENT #2 so it passes all the test cases. The program must pass the test case when uploaded to Hypergrade.    Chapter 9. PC #8. 8. Sum of Numbers in a String (page 610) Write a program that asks the user to enter a series of numbers separated by commas. Here are two examples of valid input: 7,9,10,2,18,6 8.777,10.9,11,2.2,-18,6 The program should calculate and display the sum of all the numbers. Input Validation 1. Make sure the string only contains numbers and commas (valid symbols are '0'-'9', '-', '.', and ','). 2. If the string is empty, a messages should be displayed, saying that the string is empty.   Test Case 1     Enter a series of numbers separated only by commas or type QUIT to exit:\n7,9,10,2,18,6ENTERThe sum of those numbers is 52.00\nEnter a series of numbers separated only by commas or type QUIT to exit:\nENTEREmpty string.\nEnter a series of numbers separated only by…