//BMIExceptHandlingWithMethods.java

import java.util.Scanner;

public class BMIExceptHandlingWithMethods
{
    public static int getWeight(Scanner scnr) throws Exception
    {
        int weightParam; // User defined weight (lbs)

        // Get user data
        System.out.print("Enter weight (in pounds): ");
        weightParam = scnr.nextInt();

        // Error checking, non-negative weight
        if (weightParam < 0)
        {
            throw new Exception("Invalid weight.");
        }
        return weightParam;
    }

    public static int getHeight(Scanner scnr) throws Exception
    {
        int heightParam; // User defined height (in)

        // Get user data
        System.out.print("Enter height (in inches): ");
        heightParam = scnr.nextInt();

        // Error checking, non-negative height
        if (heightParam < 0)
        {
            throw new Exception("Invalid height.");
        }
        return heightParam;
    }

    public static void main(String[] args)
    {
        Scanner scnr = new Scanner(System.in);
        int weightVal; // User defined weight (lbs)
        int heightVal; // User defined height (in)
        float bmiCalc; // Resulting BMI
        char quitCmd;  // Indicates quit/continue

        quitCmd = 'a';

        while (quitCmd != 'q')
        {
            try
            {
                //Get user data
                weightVal = getWeight(scnr);
                heightVal = getHeight(scnr);

                // Calculate BMI and print user health info if no input error
                // Source: http://www.cdc.gov/
                bmiCalc = ((float) weightVal /
                           (float)(heightVal * heightVal)) * 703.0f;

                System.out.println("BMI: " + bmiCalc);
                System.out.println("(CDC: 18.6-24.9 normal)");
            }
            catch (Exception excpt)
            {
                // Prints the error message passed by throw statement
                System.out.println(excpt.getMessage());
                System.out.println("Cannot compute health info.");
            }

            // Prompt user to continue/quit
            System.out.print("\nEnter any key ('q' to quit): ");
            quitCmd = scnr.next().charAt(0);
        }
    }
}