Internationalization Slide 1©SoftMoore Consulting.

Internationalization

Slide 1©SoftMoore Consulting

Internationalization

• Internationalization – the process of designing an application so that it can be adapted to various languages and regions without engineering changes.Often abbreviated “i18n”, because there are 18 letters between the first “i” and the last “n”

• Localization – the process of adapting software for a specific region or language by adding locale-specific components and translating text.Often abbreviated as “l10n” for similar reasons

• The primary task of localization is translating the user interface elements and documentation.(language, numbers, dates, currency, etc.)

©SoftMoore Consulting Slide 2

©SoftMoore Consulting

Characteristics of anInternationalized Program

• With the addition of localized data, the same executable can run worldwide.

• Textual elements, such as status messages and the GUI component labels, are not hardcoded in the program. Instead they are stored outside the source code and retrieved dynamically.

• Support for new languages does not require recompilation.• Culturally-dependent data, such as dates and currencies,

appear in formats that conform to the end user's region and language.

• It can be localized quickly.

Slide 3

Example: Before Internationalization

public class NotI18N { static public void main(String[] args) { System.out.println("Hello."); System.out.println("How are you?"); System.out.println("Goodbye."); } }


Example: After Internationalization

public class I18NSample { static public void main(String[] args) { String language = new String(args[0]); String country = new String(args[1]);

Locale loc = new Locale(language, country); ResourceBundle messages = ResourceBundle.getBundle("MessagesBundle", loc);

System.out.println(messages.getString("greeting")); System.out.println(messages.getString("inquiry")); System.out.println(messages.getString("farewell")); } }


Running the Example

• java I18NSample fr FRBonjour.Comment allez-vous?Au revoir.

• java I18NSample en USHello.How are you?Goodbye.


Property Files for the Example

• File MessagesBundle_fr_FR.propertiesgreeting = Bonjour.farewell = Au revoir.inquiry = Comment allez-vous?

• File MessagesBundle_en_US.propertiesgreeting = Hello.farewell = Goodbye.inquiry = How are you?

File names are significant!


Topics

• Locales• Using resource bundles• Date formatting• Message formatting


Locale

• A locale defines local area configuration data– specific language– specific country– specific territory / variant (optional)

• Class Locale resides in the java.util package• Several Java classes provide methods that return

instances of Locale


Sample Language Codes

Language Code Description de German en English fr French ja Japanese ko Korean zh Chinese


Sample Country Codes

Country Code Description CN China DE Germany FR France IN India US United States


Getting the Locale

• Constructing a locale manually:Locale l = new Locale(String lang, String country);Locale l = new Locale(String lang, String country, String variant);

• Getting the default locale:Locale l = Locale.getDefault();

• Setting locale-related properties (dangerous):Properties p = System.getProperties();p.put("user.language", "fr");p.put("user.region", "CA");System.setProperties(p);


Method getLocale()

• Returns the current locale• Defined for

– Applet– Component– MessageFormat– Window

• If no locale is set, method getLocale() returns the default locale.


Available Locales

• To retrieve the available localesLocale locales[] = Locale.getAvailableLocales();

• Method locale.toString() returns concatenated values– “_fr_FR” (French/France)– “_fr_CA” (French/Canada)– “_en_US” (English/United States)

• To retrieve locale properties as strings uselocale.getLanguage()locale.getCountry()locale.getVariant()


Resource Bundles

• Isolate grouping for specific locales• Class ListResourceBundle defines a bundle within

the source code• Class PropertyResourceBundle defines a bundle via

a property file• Access is identical – names for multiple locales:

MyResourceBundleMyResourceBundle_enMyResourceBundle_fr_CAMyResourceBundle_fr_FR


Creating a Bundle as Compiled Code

• Simply extend class ListResourceBundlepublic class Training extends ListResourceBundle { static final Object[][] contents = { { "Date", "Date: " }, { "Cost", "Cost: " }, { "Location", "Location: " }, { "Title", "Training" } };

public Object[][] getContents() { return contents; } }

• Array contents provides key-value pairs


Working with a Resource Bundle

• Getting a bundleLocale l = getLocale(); ResourceBundle labels =

ResourceBundle.getBundle("Training", l);

• Using a bundlep.add(new Label(labels.getString("Date")));p.add(new Label(labels.getString("Cost")));p.add(new Label(labels.getString("Location")));add(new Label(labels.getString("Title"), Label.CENTER),

BorderLayout.NORTH);


Supporting a Different Locale

• Example: Define a Finnish bundlepublic class Training_fi extends ListResourceBundle { static final Object[][] contents = { { "Date", "Päivämäärä: " }, { "Cost", "Hinta: " }, { "Location", "Sijainti: " }, { "Title", "Koulutus" } };

public Object[][] getContents() {...} }

• Simply append "_fi" to base bundle name.


Class PropertyResourceBundle

• Initialized from property filekey=value format

• File naming conventionBundlename_localization-string.properties– TrainingSettingsBundle.properties– TrainingSettingsBundle_fi.properties

• Example file contentsDate=June 3, 1998Cost=1200.00Map=SMarea.gif


Locale-Specific Formats

• Manipulating data for different locales– NumberFormat handles number formatting and manipulation– DateFormat handles reading and displaying of dates– MessageFormat supports error and informational messages

• Example: For “June 3, 1998”– US: 6/3/98– Italy: 3/6/98– Finland: 03.06.98

• See the java.text package for details


Example: Reading Date-Related Data

Local aLocale = getLocale(); ResourceBundle settings = ResourceBundle.getBundle("Training", aLocale);String date = settings.getString("Date");DateFormat dfInput = DateFormat.getDateInstance(DateFormat.LONG, Locale.US);

Date inputDate;

try { inputDate = dfInput.parse(dateString)); }catch (ParseException e) { inputDate = null; }©SoftMoore Consulting Slide 21

Example: Writing Date-Related Data

Local aLocale = getLocale();DateFormat dfOutput = DateFormat.getDateInstance(DateFormat.SHORT, aLocale);

String dateLabelString;

try { dateLabelString = dfOutput.format(dfInput.parse(dateString)); }catch (ParseException e) { dateLabelString = dateString; }


Class NumberFormat

• Deals with reading and display of numbers, currency, and percentage

• Supports numeric output in locale-appropriate format• Example: For “1200.00”

– US: $1,200.00– Italy: L. 1.200,00– Finland: 1 200,00 mk


Example: Manipulating Currency Values

String costString = settings.getString("Cost");NumberFormat nfInput = NumberFormat.getNumberInstance(Locale.US);NumberFormat nfOutput = NumberFormat.getCurrencyInstance(aLocale));

String costLabelString;

try { Number n = nfInput.parse(costString); costLabelString = nfOutput.format(n.longValue()); }catch (ParseException e) { costLabelString = costString; }


Class MessageFormat

• Supports fill-in-the-blank (error) messages• Example

MessageFormat format1 = new MessageFormat ("File {1} overflowing filesystem {0}.");

• The {n} syntax designates string substitution area


Localized Messages

• Class MessageFormat also assists with localization of messages– can specify format of message with place holders for runtime

context– can reorder placeholders based on locale

• Example output– I/O Exception while loading: Foobar.java– Foobar.java loaded unsuccessfully: I/O Exception

or– The disk G contains 3 files. (English)– Il y a 3 fichiers sur le disque G. (French)


Using Class MessageFormat

• Define format styles:– "{0} while loading: {1}"– "{1} loaded unsuccessfully: {0}"

• Define contents– syntax {n} represents a placeholder– values start with 0

• Place parameter values in an Object arrayObject[] args = {exceptionName, filename};

• Use MessageFormat.format() to fill in placeholders


Example: Displaying Messages withMessageFormat

public class FormatIt { public static void main(String args[]) { String fmt1 = "{0} while loading: {1}"; String fmt2 = "{1} loaded unsuccessfully: {0}"; String filename = "Foobar.java"; String exceptionName = "I/O Exception"; Object[] fmtargs = {exceptionName, filename};

System.out.println( MessageFormat.format(fmt1, fmtargs)); System.out.println( MessageFormat.format(fmt2, fmtargs)); } }


Example: Displaying Messages withMessageFormat (continued)

• Output after substitutions– I/O Exception while loading: Foobar.java– Foobar.java loaded unsuccessfully: I/O Exception


Starting an Application

• For default locale, just run it• For different locale

– Set Properties from inside your program– Set Properties from command line

java -Duser.language=it -Duser.region=IT ClassSchedule


International Training


Displaying Unicode Fonts

• If your fonts are installed correctly, it works• Basic functionality only works for displaying text, not

editing it• Works for Label or Choice, for example, but not TextField


Example: Displaying Unicode Fonts

public class MyDisplay extends Frame { public static class MyCanvas extends Canvas { public MyCanvas() { setFont (new Font ("Serif", Font.PLAIN, 36)); }

public void paint (Graphics g) { String s = "\u3041\u3042\u3043\u3044\u3045"; g.drawString(s, 20, 50); } }


Example: Displaying Unicode Fonts(continued)

public MyDisplay() { super("Unicode Tester"); add(new MyCanvas(), BorderLayout.CENTER);

Choice c = new Choice(); c.addItem ("\u3041\u3042\u3043\u3044\u3045"); c.addItem ("\u3041\u3042\u3043\u3044\u3046"); add (c, BorderLayout.SOUTH); } }


Internationalization Checklist

• Identify culturally dependent data– messages – labels on GUI components– dates/times – numbers– currencies – etc

• Isolate translatable text in resource bundles• Handle compound messages• Format numbers, currencies, dates, times, etc.• Use unicode character properties• Compare strings properly (e.g., with a Collator object)• Convert non-unicode text


Online Resources

• Java Tutorial Trail on Internationalizationhttps://docs.oracle.com/javase/tutorial/i18n/

• ISO 639-1 (language codes)https://en.wikipedia.org/wiki/List_of_ISO_639-1_codes

• ISO 3166-2 (country codes)https://en.wikipedia.org/wiki/ISO_3166-2


https://docs.oracle.com/javase/tutorial/i18n/

https://docs.oracle.com/javase/tutorial/i18n/

https://en.wikipedia.org/wiki/List_of_ISO_639-1_codes

https://en.wikipedia.org/wiki/List_of_ISO_639-1_codes

https://en.wikipedia.org/wiki/ISO_3166-2

https://en.wikipedia.org/wiki/ISO_3166-2

Internationalization Slide 1©SoftMoore Consulting.

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