Program to demonstrate Wrapper Class Methods

/* Program to demonstrate Wrapper Class Methods */

import java.io.*;

class WrapperClassDemo
{
   
    public static void main(String args[])
    {
        // Converting number to object
        Float principalAmt = new Float(0);
        Float interestRate = new Float(0);
       
        int num_of_years=0;

   
            try
            {
            DataInputStream in = new DataInputStream(System.in);
            System.out.print("Enter Principal Amount : ");
            System.out.flush();
            String principalString = in.readLine();
            principalAmt = Float.valueOf(principalString); // String object to number object

            System.out.print("Enter Interest Rate : ");
            System.out.flush();
            String interestString = in.readLine();
            interestRate = Float.valueOf(interestString); // String object to number object


              System.out.print("Enter Number of years : ");
            System.out.flush();
            String yearString = in.readLine();
            num_of_years = Integer.parseInt(yearString); // Numeric Strings to numbers
            }

            catch(IOException e)
            {
            System.out.println("I/O Error");
            System.exit(1);
            }


        float TotalAmount = loan(principalAmt.floatValue(),interestRate.floatValue(),num_of_years);
        System.out.println("------------------------------");
        System.out.println("Total Amount : "+TotalAmount);
        System.out.println("------------------------------");
    }

    static float loan(float p,float r,int n)
    {
        int year = 1;
        float sum = p;
        while(year <= n)
        {
            sum = sum * (1+r);
            year = year + 1;
        }
        return sum;
    }
}