How do I get all available currency codes?

The example presented in this code snippet show you how to get the available currency codes. We will need the locale information and use the Currency class for this example.

package org.kodejava.example.util;

import java.util.Currency;
import java.util.Locale;
import java.util.Map;
import java.util.TreeMap;

public class CurrencySymbolDemo {
    public static void main(String[] args) {
        CurrencySymbolDemo cs = new CurrencySymbolDemo();

        Map<String, String> currencies = cs.getAvailableCurrencies();
        for (String country : currencies.keySet()) {
            String currencyCode = currencies.get(country);
            System.out.println(country + " => " + currencyCode);
        }
    }

    /**
     * Get the currencies code from the available locales information.
     *
     * @return a map of currencies code.
     */
    private Map<String, String> getAvailableCurrencies() {
        Locale[] locales = Locale.getAvailableLocales();

        // We use TreeMap so that the order of the data in the map sorted
        // based on the country name.
        Map<String, String> currencies = new TreeMap<>();
        for (Locale locale : locales) {
            try {
                currencies.put(locale.getDisplayCountry(),
                    Currency.getInstance(locale).getCurrencyCode());
            } catch (Exception e) {
                // when the locale is not supported
            }
        }
        return currencies;
    }
}

You will have something like this printed on the screen:

...
Honduras => HNL
Hong Kong => HKD
Hungary => HUF
Iceland => ISK
India => INR
Indonesia => IDR
Iraq => IQD
Ireland => EUR
Israel => ILS
Italy => EUR
...

How do I change the date format symbols for a specified locale?

package org.kodejava.example.text;

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

public class ChangeDateFormatSymbols {
    public static void main(String[] args) {
        Locale id = new Locale("in", "ID");
        String pattern = "EEEE, dd MMM yyyy";
        Date today = new Date();

        // Gets formatted date specify by the given pattern for
        // Indonesian Locale no changes for default date format
        // is applied here.
        SimpleDateFormat sdf = new SimpleDateFormat(pattern, id);
        String before = sdf.format(today);
        System.out.println("Before format change: " + before);

        // Create a DateFormatSymbols object for Indonesian locale.
        DateFormatSymbols dfs = new DateFormatSymbols(id);

        // Gets String array of default format of weekdays.
        String[] days = dfs.getWeekdays();
        String newDays[] = new String[days.length];
        for (int i = 0; i < days.length; i++) {
            // For each day, apply toUpperCase() method to
            // capitalized it.
            newDays[i] = days[i].toUpperCase();
        }

        // Set String array of weekdays.
        dfs.setWeekdays(newDays);

        // Gets String array of default format of short months.
        String[] shortMonths = dfs.getShortMonths();
        String months[] = new String[shortMonths.length];
        for (int j = 0; j < shortMonths.length; j++) {
            // For each short month, apply toUpperCase() method
            // to capitalized it.
            months[j] = shortMonths[j].toUpperCase();
        }

        // Set String array of short months.
        dfs.setShortMonths(months);

        // Create a SimpleDateFormat object by given pattern and 
        // symbol and then format the date object as String.
        sdf = new SimpleDateFormat(pattern, dfs);
        String after = sdf.format(today);
        System.out.println("After change format : " + after);
    }
}

Here are the output of our program:

Before format change: Kamis, 12 Apr 2018
After change format : KAMIS, 12 APR 2018

How do I get a formatted date for a specific pattern and locale?

If you want to change formatting styles provided by DateFormat, you can uses SimpleDateFormat class. The SimpleDateFormat class is locale-sensitive.

If you instantiate SimpleDateFormat without a Locale parameter, it will format the date and time according to the default Locale. Both the pattern and the Locale determine the format. For the same pattern, SimpleDateFormat may format a date and time differently if the Locale varies.

package org.kodejava.example.text;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;

public class SimpleDateFormatChangeLocalePattern {
    public static void main(String[] args) {
        String pattern = "dd-MMM-yyyy";
        Date today = new Date();

        // Gets a formatted date according to the given pattern.
        // Here only the pattern is passed as argument of the
        // SimpleDateFormat constructor, so it will format the
        // date according to the default Locale.
        SimpleDateFormat sdf = new SimpleDateFormat(pattern);
        String local = sdf.format(today);
        System.out.println("Date in default locale: " + local);

        Locale[] locales = {
            Locale.CANADA,
            Locale.FRANCE,
            Locale.GERMANY,
            Locale.US,
            Locale.JAPAN
        };

        for (Locale locale : locales) {
            // Format a date according to the given pattern for each locale.
            sdf = new SimpleDateFormat(pattern, locale);
            String after = sdf.format(today);
            System.out.println(locale.getDisplayCountry() + " | format: " + after);
        }
    }
}

Here are the variety of output produces when formatting a date in the same date pattern but varies in Locale

Date in default locale: 12-Apr-2018
Canada | format: 12-Apr-2018
France | format: 12-avr.-2018
Germany | format: 12-Apr-2018
United States | format: 12-Apr-2018
Japan | format: 12-4-2018

How do I get default date and time format for a defined country?

The DateFormat class allows you to format dates and times with predefined styles in a locale-sensitive manner. Formatting dates or times with the DateFormat class is a two-step process.

First, you create a formatter with the getDateInstance() method for formatting date or getTimeInstance() method for formatting time or getDateTimeInstance() when you want formatting both date and time.

Second, you invoke the format method, which returns a String containing the formatted date. The following example formats today’s date and time by calling those two methods.

package org.kodejava.example.text;

import java.text.DateFormat;
import java.util.Date;
import java.util.Locale;

public class LocaleDateTime {
    public static void main(String[] args) {
        Locale[] locales = {Locale.CANADA, Locale.FRANCE, Locale.GERMANY,
            Locale.US, Locale.JAPAN};

        Date today = new Date();
        for (Locale locale : locales) {
            StringBuilder sb = new StringBuilder();
            sb.append(locale.getDisplayCountry())
                .append(System.lineSeparator());
            sb.append("--------------------------------")
                .append(System.lineSeparator());

            // Gets a DateFormat instance for the specified locale
            // and format a date object by calling the format
            // method.
            DateFormat df = DateFormat.getDateInstance(DateFormat.DEFAULT, locale);
            String date = df.format(today);
            sb.append("Default date format: ").append(date)
                .append(System.lineSeparator());

            // Gets a DateFormat instance for the specified locale
            // and format a time information by calling the format
            // method.
            DateFormat tf = DateFormat.getTimeInstance(DateFormat.DEFAULT, locale);
            String time = tf.format(today.getTime());
            sb.append("Default time format: ").append(time)
                .append(System.lineSeparator());

            System.out.println(sb.toString());
        }

        // Gets date and time formatted value for Italy locale using
        // To display a date and time in the same String, create the
        // formatter with the getDateTimeInstance method.
        // The first parameter is the date style, and the second is
        // the time style. The third parameter is the Locale
        DateFormat dtf = DateFormat.getDateTimeInstance(DateFormat.DEFAULT,
            DateFormat.DEFAULT, Locale.ITALY);
        String datetime = dtf.format(today);

        System.out.println("date time format in " +
            Locale.ITALY.getDisplayCountry() + ": " + datetime);
    }
}

Here are the produces output:

Canada
--------------------------------
Default date format: 10-Apr-2018
Default time format: 10:18:11 PM

France
--------------------------------
Default date format: 10 avr. 2018
Default time format: 22:18:11

Germany
--------------------------------
Default date format: 10.04.2018
Default time format: 22:18:11

United States
--------------------------------
Default date format: Apr 10, 2018
Default time format: 10:18:11 PM

Japan
--------------------------------
Default date format: 2018/04/10
Default time format: 22:18:11

date time format in Italy: 10-apr-2018 22.18.11

How do I change the currency symbol?

This example show you how to change the currency symbol for the defined locale using the DecimalFormatSymbols.setCurrencySymbol() method. After changing the currency symbol, the DecimalFormatSymbols instance is passed to the DecimalFormat object which does the formatting.

package org.kodejava.example.text;

import java.text.DecimalFormat;
import java.text.DecimalFormatSymbols;
import java.text.NumberFormat;
import java.util.Locale;

public class CurrencyFormatSymbols {
    public static void main(String[] args) {
        double number = 123456.789;

        Locale[] locales = {Locale.CANADA, Locale.GERMANY, Locale.UK, Locale.ITALY, Locale.US};

        String[] symbols = {"CAD", "EUR", "GBP", "ITL", "USD"};

        for (int i = 0; i < locales.length; i++) {
            // Gets currency's formatted value for each locale
            // without change the currency symbol
            DecimalFormat formatter = (DecimalFormat) NumberFormat.getCurrencyInstance(locales[i]);
            String before = formatter.format(number);

            // Create a DecimalFormatSymbols for each locale and sets
            // its new currency symbol.
            DecimalFormatSymbols symbol = new DecimalFormatSymbols(locales[i]);
            symbol.setCurrencySymbol(symbols[i]);

            // Set the new DecimalFormatSymbols into formatter object.
            formatter.setDecimalFormatSymbols(symbol);

            // Gets the formatted value
            String after = formatter.format(number);
            System.out.println(locales[i].getDisplayCountry() + " | before: " + before + " | after: " + after);
        }
    }
}

Here is are the result of our program:

Canada | before: $123,456.79 | after: CAD123,456.79
Germany | before: 123.456,79 € | after: 123.456,79 EUR
United Kingdom | before: £123,456.79 | after: GBP123,456.79
Italy | before: € 123.456,79 | after: ITL 123.456,79
United States | before: $123,456.79 | after: USD123,456.79

How do I change number format symbols?

You can use the DecimalFormatSymbols class to change the symbols that appear in the formatted numbers. These symbols include the decimal separator which can be changed using the setDecimalSeparator(), the grouping separator which can be change using the setGroupingSeparator() method. You can also alter the minus sign, and the percent sign, among others.

package org.kodejava.example.text;

import java.text.DecimalFormat;
import java.text.DecimalFormatSymbols;
import java.util.Locale;

public class NumberFormatSymbol {
    public static void main(String[] args) {
        DecimalFormat formatter;
        String pattern = "###,###.##";
        double number = 123456.789;

        // Create a DecimalFormatSymbols object for United States
        // locale.
        DecimalFormatSymbols dfs = new DecimalFormatSymbols(Locale.US);

        // Create a format object with the given pattern without
        // change the locale dfs then format the given value.
        formatter = new DecimalFormat(pattern);
        String before = formatter.format(number);

        // Change the decimal separator and grouping separator symbol.
        dfs.setDecimalSeparator(',');
        dfs.setGroupingSeparator('.');
        dfs.setMinusSign('-');
        dfs.setPercent('%');

        // Create a format object with the given pattern and symbol
        // then format the given value.
        formatter = new DecimalFormat(pattern, dfs);
        String after = formatter.format(number);

        System.out.println("before: " + before + " | after: " + after);
    }
}

How do I change DecimalFormat pattern?

To change the pattern use by the DecimalFormat when formatting a number we can use the DecimalFormat.applyPattern() method call. In this example we use three different patterns to format the given input number. The pattern determines what the formatted number looks like.

package org.kodejava.example.text;

import java.text.DecimalFormat;
import java.text.NumberFormat;
import java.util.Locale;

public class FormatterPattern {
    public static void main(String[] args) {
        String[] patterns = {"###,###,###.##", "000000000.00", "$###,###.##"};

        double before = 1234567.899;

        // To obtain a NumberFormat for a specific locale,
        // including the default locale, call one of NumberFormat's
        // factory methods, such as getNumberInstance(). Then cast
        // it into a DecimalFormat.
        DecimalFormat format = (DecimalFormat) NumberFormat.getNumberInstance(Locale.UK);
        for (String pattern : patterns) {
            // Apply the given pattern to this Format object
            format.applyPattern(pattern);

            // Gets the formatted value
            String after = format.format(before);

            System.out.printf("Input: %s, Pattern: %s, Output: %s%n", before, pattern, after);
        }
    }
}

The output of the program shown below:

Input: 1234567.899, Pattern: ###,###,###.##, Output: 1,234,567.9
Input: 1234567.899, Pattern: 000000000.00, Output: 001234567.90
Input: 1234567.899, Pattern: $###,###.##, Output: $1,234,567.9

How do I format number as percentage string?

The NumberFormat.getPercentInstance() method returns a percentage format for the specified locale. In this example we will format the number as percentage using the Locale.US locale.

package org.kodejava.example.text;

import java.text.NumberFormat;
import java.util.Locale;

public class LocalePercentageFormat {
    public static void main(String[] args) {
        // Format percentage for Locale.US locale with this formatter,
        // a decimal fraction such as 0.75 is displayed as 75%
        double number = 0.25;
        NumberFormat format = NumberFormat.getPercentInstance(Locale.US);
        String percentage = format.format(number);
        System.out.println(number + " in percentage = " + percentage);
    }
}

The following line is the output of the program:

0.25 in percentage = 25%

How do I format a number as currency string?

Creating a financial application requires you to format number as a currency. It should includes the correct thousands separator, decimal separator and the currency symbol. For this purpose you can use the NumberFormat.getCurrencyInstance() method and pass the correct Locale to get the currency format that you want.

package org.kodejava.example.text;

import java.text.NumberFormat;
import java.util.Locale;

public class LocaleCurrencyFormat {
    public static void main(String[] args) {
        Double number = 1500D;

        // Format currency for Canada locale in Canada locale, 
        // the decimal point symbol is a comma and currency
        // symbol is $.
        NumberFormat format = NumberFormat.getCurrencyInstance(Locale.CANADA);
        String currency = format.format(number);
        System.out.println("Currency in Canada : " + currency);

        // Format currency for Germany locale in German locale,
        // the decimal point symbol is a dot and currency symbol
        // is €.
        format = NumberFormat.getCurrencyInstance(Locale.GERMANY);
        currency = format.format(number);
        System.out.println("Currency in Germany: " + currency);
    }
}

Here is an output for the currency format using the Locale.CANADA and Locale.GERMANY.

Currency in Canada : $1,500.00
Currency in Germany: 1.500,00 €

How do I create a Locale object using a variant?

Font differences may force you to use different characters on different platforms. You could then define the Locale objects with the variant codes to identify those differences. The variant codes conform to no standard. They are arbitrary and specific to your application. If you create Locale objects with variant codes only your application will know how to deal with them.

In this example instead of demonstrating to use a different font for different platform we simplify it to just print a different message. We create three different resource bundles for each platform, the MessagesBundle_fr_FR_UNIX.properties, MessagesBundle_fr_FR_MAC.properties and MessagesBundle_fr_FR_WIN.properties. These files will contains different message for each platform.

package org.kodejava.example.util;

import java.util.Locale;
import java.util.ResourceBundle;

public class LocalePlatform {
    public static void main(String[] args) {
        ResourceBundle res;
        String language = "fr";
        String country = "FR";

        // Construct a locale from language, country, variant. Where the variant
        // can be a variant vendor and browser specific code.
        Locale unix = new Locale(language, country, "UNIX");
        res = ResourceBundle.getBundle("MessagesBundle", unix);
        System.out.println("UNIX: " + res.getString("birthday"));

        Locale mac = new Locale(language, country, "MAC");
        res = ResourceBundle.getBundle("MessagesBundle", mac);
        System.out.println("MAC : " + res.getString("birthday"));

        Locale windows = new Locale(language, country, "WIN");
        res = ResourceBundle.getBundle("MessagesBundle", windows);
        System.out.println("WIN : " + res.getString("birthday"));
    }
}

Here are the contents of the resource bundle files:

MessagesBundle_fr_FR_UNIX.properties

birthday=Unix, Joyeux anniversaire à vous!

MessagesBundle_fr_FR_MAC.properties

birthday=Mac, Joyeux anniversaire à vous!

MessagesBundle_fr_FR_WIN.properties

birthday=Windows, Joyeux anniversaire à vous!