Module# 15: Java Utility Lecture#59: Miscellaneous Utilities

// Example 59.1 : Simple StringTokenizer parsing

// Demonstrate simple parsing a text

import java.util.StringTokenizer;

class StringParsingDemo1{

public static void main(String args[]){

StringTokenizer st = new StringTokenizer(“Joy with Java"," ");

while (st.hasMoreTokens()) {

System.out.println(st.nextToken());

}

}

// Example 59.2 : StringTokenizer parsing with key

// Demonstrate StringTokenizer.

import java.util.StringTokenizer;

class STDemo{

static String in = "title=Java: Data Structures;" +

"author=DS;" + "publisher=NPTEL;" + "copyright=2020";

public static void main(String args[]) {

StringTokenizer st = new StringTokenizer(in, "=;");

while(st.hasMoreTokens()) {

String key = st.nextToken();

String val = st.nextToken();

System.out.println(key + "\t" + val);

}

}

}

// Example 59.3 : Getting the current date and time

// Show date and time using only Date methods.

import java.util.Date;

class DateDemo {

public static void main(String args[]) {

// Instantiate a Date object

Date date = new Date();

// display time and date using toString()

System.out.println(date);

// Display number of milliseconds since midnight, January 15, 2020 GMT

long msec = date.getTime();

System.out.println("Milliseconds since Jan. 15, 2020 GMT = " + msec);

}

}

// Example 59.4 : Demonstration of several calendar methods

// Demonstrate Calendar

import java.util.Calendar;

class CalendarDemo {

public static void main(String args[]) {

// Create a calendar initialized with the

// current date and time in the default

// locale and timezone.

Calendar calendar = Calendar.getInstance();

// Display current time and date information.

System.out.print("Date: ");

System.out.print(calendar);

System.out.print("Time: ");

System.out.print(calendar.get(Calendar.HOUR) + ":");

System.out.print(calendar.get(Calendar.MINUTE) + ":");

System.out.println(calendar.get(Calendar.SECOND));

// Set the time and date information and display it.

calendar.set(Calendar.HOUR, 10);

calendar.set(Calendar.MINUTE, 29);

calendar.set(Calendar.SECOND, 22);

System.out.print("Updated time: ");

System.out.print(calendar.get(Calendar.HOUR) + ":");

System.out.print(calendar.get(Calendar.MINUTE) + ":");

System.out.println(calendar.get(Calendar.SECOND));

}

}

// Example 59.5 : Demonstration of several calendar methods

// Program to demonstrate add() method of Calendar class

import java.util.*;

public class Calendar5 {

public static void main(String[] args) {

// creating calendar object

Calendar calendar = Calendar.getInstance();

calendar.add(Calendar.DATE, -15);

System.out.println("15 days ago: " + calendar.getTime());

calendar.add(Calendar.MONTH, 4);

System.out.println("4 months later: " + calendar.getTime());

calendar.add(Calendar.YEAR, 2);

System.out.println("2 years later: " + calendar.getTime());

}

}

// Example 59.6 : Getting the current date and time

// Demonstrate GregorianCalendar

import java.util.*;

class GregorianCalendarDemo {

public static void main(String args[]) {

String months[] = {"Jan", "Feb", "Mar", "Apr",

"May", "Jun", "Jul", "Aug",

"Sep", "Oct", "Nov", "Dec"};

int year;

// Create a Gregorian calendar initialized

// with the current date and time in the

// default locale and timezone.

GregorianCalendar gcalendar = new GregorianCalendar();

// Display current time and date information.

System.out.print("Date: ");

System.out.print(months[gcalendar.get(Calendar.MONTH)]);

System.out.print(" " + gcalendar.get(Calendar.DATE) + " ");

System.out.println(year = gcalendar.get(Calendar.YEAR));

System.out.print("Time: ");

System.out.print(gcalendar.get(Calendar.HOUR) + ":");

System.out.print(gcalendar.get(Calendar.MINUTE) + ":");

System.out.println(gcalendar.get(Calendar.SECOND));

// Test if the current year is a leap year

if(gcalendar.isLeapYear(year)) {

System.out.println("The current year is a leap year");

}

else {

System.out.println("The current year is not a leap year");

}

}

}

// Example 59.7 : Currency method

// Demonstrate Currency.

import java.util.*;

class CurDemo {

public static void main(String args[]) {

Currency c;

c = Currency.getInstance(Locale.US);

System.out.println("Symbol: " + c.getSymbol());

System.out.println("Default fractional digits: " +

c.getDefaultFractionDigits());

}

}