switch (option)
      {
         // option 1
         case 1:

Enter your option (1, 2 or x) : x
Exception in thread "main" java.util.InputMismatchException
        at java.util.Scanner.throwFor(Scanner.java:819)
        at java.util.Scanner.next(Scanner.java:1431)
        at java.util.Scanner.nextInt(Scanner.java:2040)
        at java.util.Scanner.nextInt(Scanner.java:2000)
        at LoanCalculator.main(LoanCalculator.java:41)

import java.io.*;
public class DICSwitch {
    
    public static void main (String args[])
    {
        String in = "";
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        try {
        
        in = reader.readLine();}
        catch (IOException e) {
            System.out.println(e);
        }
        int choice = 0;
        if (in.equals("x")) {
            choice = 3;
            
        }
        else
        try {
            choice = Integer.parseInt(in);
        } catch (NumberFormatException e) {
            System.out.println(e);
        }
        switch (choice)
        {
            case 1: System.out.println("Choice = 1");
            break;
            case 2: System.out.println("Choice = 2");
            break;
            case 3: System.out.println("Choice = 3");
            break;
            default: System.out.println("Choice invalid");
        }
        System.exit(0);
    }
    
    
}