How do I get a list of weekday names?

By I Wayan Saryada in Core API, Text Package 0 Comment

The example code below helps you to get all weekday names as an array of string. The first method, getWeekdays() return the full name string while the second method getShortWeekdays() return the short name of the weekday.

package org.kodejava.text;

import java.text.DateFormatSymbols;

public class WeekdayNames {
    public static void main(String[] args) {
        DateFormatSymbols dfs = new DateFormatSymbols();

        String[] weekdays = dfs.getWeekdays();
        for (String weekday : weekdays) {
            System.out.println("weekday = " + weekday);
        }

        String[] shortWeekdays = dfs.getShortWeekdays();
        for (String shortWeekday : shortWeekdays) {
            System.out.println("shortWeekday = " + shortWeekday);
        }
    }
}

The results of the code above are:

weekday = 
weekday = Sunday
weekday = Monday
weekday = Tuesday
weekday = Wednesday
weekday = Thursday
weekday = Friday
weekday = Saturday
shortWeekday = 
shortWeekday = Sun
shortWeekday = Mon
shortWeekday = Tue
shortWeekday = Wed
shortWeekday = Thu
shortWeekday = Fri
shortWeekday = Sat

How do I get a list of month names?

By I Wayan Saryada in Core API, Text Package 6 Comments

The example code below helps you to get all month names as an array of String. The first method, getMonths() return the full name string while the second method getShortMonths() return the short name of the month.

package org.kodejava.text;

import java.text.DateFormatSymbols;
import java.util.Locale;

public class MonthNames {
    public static void main(String[] args) {
        String[] months = new DateFormatSymbols().getMonths();
        for (String month : months) {
            System.out.println("month = " + month);
        }

        String[] shortMonths = new DateFormatSymbols().getShortMonths();
        for (String shortMonth : shortMonths) {
            System.out.println("shortMonth = " + shortMonth);
        }

        DateFormatSymbols dfs = new DateFormatSymbols(Locale.GERMANY);
        String[] germanyMonths = dfs.getMonths();
        for (String germanyMonth : germanyMonths) {
            System.out.println("germanyMonth = " + germanyMonth);
        }

        String[] germanyShortMonths = dfs.getShortMonths();
        for (String germanyShortMonth : germanyShortMonths) {
            System.out.println("germanyShortMonth = "
                    + germanyShortMonth);
        }
    }
}

The results of the code above are:

month = January
month = February
...
month = December
month = 
shortMonth = Jan
shortMonth = Feb
...
shortMonth = Dec
shortMonth = 
germanyMonth = Januar
germanyMonth = Februar
...
germanyMonth = Dezember
germanyMonth = 
germanyShortMonth = Jan
germanyShortMonth = Feb
...
germanyShortMonth = Dez
germanyShortMonth =

How do I convert String into Date Object in Java?

By I Wayan Saryada in Core API, Text Package 0 Comment

The following code shows how we can convert a string representation of date into java.util.Date object.

To convert a string of date we can use the help from java.text.SimpleDateFormat that extends java.text.DateFormat abstract class.

package org.kodejava.text;

import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.time.LocalDate;
import java.time.format.DateTimeFormatter;
import java.util.Date;

public class ConvertStringToDateExample {
    public static void main(String[] args) {
        String pattern = "dd/MM/yyyy";
        String date = "15/09/2021";

        try {
            DateFormat df = new SimpleDateFormat(pattern);
            Date today = df.parse(date);
            System.out.println("Today = " + df.format(today));
        } catch (ParseException e) {
            e.printStackTrace();
        }

        // Using Java 8 Date and Time
        DateTimeFormatter formatter = DateTimeFormatter.ofPattern(pattern);
        LocalDate localDate = LocalDate.parse(date, formatter);
        System.out.println("Today = " + localDate.format(formatter));
    }
}

And here is the result of our code:

Today = 15/09/2021
Today = 15/09/2021

The example starts by creating an instance of SimpleDateFormat with dd/MM/yyyy format which mean that the date string is formatted in day-month-year sequence.

Finally, using the parse(String source) method we can get the Date instance. Because parse method can throw java.text.ParseException exception if the supplied date is not in a valid format; we need to catch it.

Here are the list of defined patterns that can be used to format the date taken from the Java class documentation.

Letter Date / Time Component Examples
G Era designator AD
y Year 1996; 96
M Month in year July; Jul; 07
w Week in year 27
W Week in month 2
D Day in year 189
d Day in month 10
F Day of week in month 2
E Day in week Tuesday; Tue
a Am/pm marker PM
H Hour in day (0-23) 0
k Hour in day (1-24) 24
K Hour in am/pm (0-11) 0
h Hour in am/pm (1-12) 12
m Minute in hour 30
s Second in minute 55
S Millisecond 978
z Time zone Pacific Standard Time; PST; GMT-08:00
Z Time zone -0800