Could someone help me with this

Main topics: User validated input Basic String Methods if & if else Statements Loop Statements. Program Specification: Write a Java program that emulates a simple binary calculator: Declare and initialize a String variable (bitString) to "". Declare and initialize an int variable (resultSoFar) to 0. Display the current expression to the screen Repeat the following until the (Exit) option is selected: 1. Display a menu which gives the user the choice of the following menu options: 0Shift Left, Add O 1 Shift Left, Add 1 2 Exit, Evaluate. and uses a user validation loop to read their response into a String variable. Note: You must repeatedly get the users response until it is exactly one of the characters 0 12 2. If (Exit) was NOT selected: (a) Update the (bitString) string: Add the selected operation string to the end of (bitString) + "'0'' or ''1' (b) Display the current bitstring to the screen (c) Update the numeric result of the bitstring (resultSoFar): resultSoFar = 2* resultSoFar + 0 or resultSoFar = 2*resultSoFar +1. Display the entire expression with its result. Grading: Performance Indicator [1] [2] [3] Readability and documentation 1 2 2 Use of loop(s) operators 1 2 2 Functional requirements Efficiency 2 3 4 1 2 2 Sample run(s): RUN1 0Shift Left, Add O 1 Shift Left, Add 1