Chapter 2 Question 2.8, Introduction to Java Programming, Tenth Edition Y. Daniel LiangY.

(Current time) Listing 2.7, ShowCurrentTime.java, gives a program that displays the current time in GMT. Revise the program so that it prompts the user to enter the time zone offset to GMT and displays the time in the specified time zone

Solution

import java.util.Scanner;

public class Exercise_02_08

{

    public static void main(String[] args)

    {

        Scanner input = new Scanner(System.in); // Create new Scanner object

        // Prompt user to enter the time offset of GMT

        System.out.print("Enter the time zone offset to GMT: ");

        int offset = input.nextInt();

        // Obtain the total milliseconds since midnight, Jan 1, 1970

        long totalMilliseconds = System.currentTimeMillis();

        // Obtain the total seconds since midnight, Jan 1, 1970

        long totalSeconds = totalMilliseconds / 1000;

        // Compute the current second in the minute in the hour

        long currentSecond = totalSeconds % 60;

        // Obtain the total minutes

        long totalMinutes = totalSeconds / 60;

        // Compute the current minute in the hour

        long currentMinute = totalMinutes % 60;

        // Obtain the total hours

        long totalHours = totalMinutes / 60;

        // Compute the current hour

        long currentHour = totalHours % 24;

        currentHour = currentHour + offset;

        // Display results

        System.out.println("Current time is " + currentHour + ":"

            + currentMinute + ":" + currentSecond);

    }

}