Write the main method that will test the following methods: In java please

Write the method to convert Celsius to Fahrenheit.

Write the method to convert Fahrenheit to Celsius

Write a method operator(a,b,c) which will receive 2 integers and one of the 5 operators (*,/,+ -, %) as a character and perform the operation and return the integer value . Example operator(2,3,*) will return a 6. (assume no division by zero!))

Write the overloaded method operator(a,b,c) which will receive 2 doubles and one of the 4 operators (*,/,+ -) as a character and perform the operation and return the integer value . Example operator(2.1,3,*) will return a 63. (assume no division by zero!))

Write the method sumOfDigits(a) which will receive and integer and return the sum of their digits. (This was a lab!!) Example sumOfDigits(941) return 15.