please do this in java! 3. RetailItem Exceptions Programming Challenge 4 of Chapter 6 required you to write a RetailItem class that holds data pertaining to a retail item. Write an exception class that can be instantiated and thrown when a negative number is given for the price. Write another exception class that can be instantiated and thrown when a negative number is given for the units on hand. Demonstrate the exception classes in a program. /** *Description: This program will displays a string without any user interaction *Class: Fall - COSC 1437.81002 *Assignment1: Hello World *Date: 08/15/2011 *@author  Zoltan Szabo *@version 0.0.0 */    For each method, you will also be required to create docstring as follows: /** * @param String as args * @return Termination code as int, 0 for normal, anything else is error condition * @throws Nothing is implemented */     Flowcharts/UML and Pseudo code   All assignment questions must show design flowchart/UML and/or pseudo code unless otherwise stated for the assignment by your instructor.  Flowcharts/UMLs can be created via an application (DIA) or drawn by hand and photographed for submission.    Here is the information about chapter 6   Chapter 6 - Programming Challenge 4,8 4. RetailItem Class Write a class named RetailItem that holds data about an item in a retail store. The class should have the following fields: • description. The description field references a String object that holds a brief description of the item. • unitsOnHand. The unitsOnHand field is an int variable that holds the number of units currently in inventory. • price. The price field is a double that holds the item’s retail price. Write a constructor that accepts arguments for each field, appropriate mutator methods that store values in these fields, and accessor methods that return the values in these fields. Once you have written the class, write a separate program that creates three RetailItem objects and stores the following data in them:                     Description                    Units on Hand            Price Item #1       Jacket                            12                               59.95 Item #2        Designer Jeans             40                              34.95 Item #3        Shirt                               20                              24.95   8. Temperature Class Write a Temperature class that will hold a temperature in Fahrenheit, and provide methods to get the temperature in Fahrenheit, Celsius, and Kelvin. The class should have the following field: • ftemp – A double that holds a Fahrenheit temperature. The class should have the following methods: • Constructor – The constructor accepts a Fahrenheit temperature (as a double) and stores it in the ftemp field. • setFahrenheit – The setFahrenheit method accepts a Fahrenheit temperature (as a double) and stores it in the ftemp field. • getFahrenheit – Returns the value of the ftemp field, as a Fahrenheit temperature (no conversion required). • getCelsius – Returns the value of the ftemp field converted to Celsius. • getKelvin – Returns the value of the ftemp field converted to Kelvin. Use the following formula to convert the Fahrenheit temperature to Celsius: Celsius = (5/9) * (Fahrenheit - 32) Use the following formula to convert the Fahrenheit temperature to Kelvin: Kelvin = ((5/9) * (Fahrenheit - 32)) + 273 Demonstrate the Temperature class by writing a separate program that asks the user for a Fahrenheit temperature. The program should create an instance of the Temperature class, with the value entered by the user passed to the constructor. The program should then call the object’s methods to display the temperature in Celsius and Kelvin.