Java programming language, read instructions carefully

An InputMismatchException is thrown by a Scanner to indicate that the token retrieved does not match the pattern for the expected type, or that the token is out of range for the expected type. For example, if you use the nextDouble to read a token that is not of the type double. Write a program that prompts the user to enter a mathematical formula (e.g. 4.3 + 5.1) and then displays the result. Your then displays the result. Your program should prompt the user to try again if the input has an invalid number or invalid operator (i.e., valid operators are: +, -/, and *). Assume the user enters spaces between the operands and the operator. Read the numbers using the Scanner's nextDouble method, and the operator using the next method. Sample run Enter a simple mathematical formula: 9.1 plus 4.2 Invalid Operator. 9.1x + 4.2 Invalid number format. 9.1 + 4.2 Result: 13.3