Chapter 9, Problem 3E

Exception class:

The exception class to find whether the time entered is valid or not. The time should be in the format “hour:minute” followed by “am” or “pm”.

InvalidFormattingException.java:

//Create a class that extends Exception

public class InvalidFormattingException extends Exception

{

    //Define a parameterized constructor

    public InvalidFormattingException(String reason)

    {

//Call the parent class's method by passing a message

        super(reason);

    }

}

Explanation:

The above class “InvalidFormattingException” occurs when the time entered by the user in invalid.

Complete program:

Main.java:

//Import required packages

import java.util.*;

import java.util.Scanner;

//Define the main class

class Main

{

    //Declare required variables

    private int hour, minute;

    private boolean isAM;

    //Constructor

    public Main()

    {

        //Instantiate the values

        hour = 0;

        minute = 0;

        isAM = false;

    }

    //Function definition to set the time

public void setTimeTo(String aTime) throws InvalidFormattingException

    {

        //Declare required variables

        int hourFound;

        int minuteFound;

        String indicatorFound;

        //Create an object for the scanner class

        Scanner reader = new Scanner(aTime);

        //Split using the delimiter

        reader.useDelimiter(":");

        //Try block

        try

        {

            //Assign the hour

            hourFound = reader.nextInt();

        }

        //Catch the exception

        catch (Exception e)

        {

            //Throw the exception with a message

throw new InvalidFormattingException("Hour not an integer");

        }

        //Get the remaining string

        String restOfString = reader.next();

        reader = new Scanner(restOfString);

        //Remove the last two characters

        if(restOfString.length()<3)

            //Throw the exception

throw new InvalidFormattingException("Bad format");

        //Get the substring

String minuteString = restOfString.substring(0, restOfString.length()-2);

        //Get the substring

String amString = restOfString.substring(restOfString.length()-2);

        //Try block

        try

        {

            //Convert the minute to integer

minuteFound = Integer.parseInt(minuteString);

        }

        //Catch the exception

        catch (Exception e)

        {

            //Throw the exception

throw new InvalidFormattingException("Minute not an integer");

        }

        //Check condition

if(!amString.equals("am") && !amString.equals("pm"))

            //Throw the exception with a message

throw new InvalidFormattingException("Did not have am/pm");

        //Assign the value

        hour = hourFound;

        //Assign the value

        minute = minuteFound;

        //Check if the string is am

        if(amString...