Quick Start on Internationalization using Java

HTML Demo - http://www.jag-s.org/~wailian/TestI18N/html/TestI18N.html

WML Demo - http://www.jag-s.org/~wailian/TestI18N/wml/TestI18N.wml

Click here to download all the source files and examples.

The I18N.jar file consists of all the relevant classes and methods I've developed for Internationalization using Java. Refer to I18N API documentation for more details.

Steps:

Create the Default Properties File

A properties file is a simple text file. You can create and maintain a properties file with just about any text editor.

The name of this file begins with the base name of your ResourceBundle and ends with the .properties suffix.

MessagesBundle.properties file:

# This is the MessagesBundle.properties file
greetings = Hello.
farewell = Goodbye.
inquiry = How are you?

Note that in the preceding file the comment lines begin with a pound sign (#). The other lines contain key-value pairs. The key is on the left side of the equal sign and the value is on the right.

Create Additional Properties Files as Needed (To support additional Locales)

MessagesBundle_zh_CN.properties file [Language code for Chinese (zh) and Country code for China (CN)]:

# This is the MessagesBundle_zh_CN.properties file
greetings = \u4F60\u597D\u3002
farewell = \u518D\u89C1\u3002
inquiry = \u4F60\u597D\u5417?

Notice that the name of this file, like that of the default file, begins with the base name MessagesBundle and ends with the .properties suffix. However, since this file is intended for a specific Locale, the base name is followed by the language code and country code.

Note:
To indicate Unicode characters that cannot be represented in ASCII
=> Use the \uXXXX escape sequence where XXXX is the hex representation (i.e. 2 bytes / 16-bits).

Create Class Files serving the same purpose as the Properties Files (Optional)

ListResourceBundle objects contain an array of key-value pairs. You specify the key, which must be a String, when you want to retrieve the value from the ResourceBundle. The value is the locale-specific object.

MessagesBundle_zh_CN.java file [Language code for Chinese (zh) and Country code for China (CN)]:

package com.mot.TestI18N.ResourceBundle ;

import java.util.ListResourceBundle ;

/**
* Class for zh CN ResourceBundle (MessagesBundle_zh_CN.java).
*
* @author Chue Wai Lian
* @version
*
* 1.0.0 08 Mar 2001
* 1st release.
*/
public class MessagesBundle_zh_CN extends ListResourceBundle
{
    public Object[][] getContents()
    {
        return( contents ) ;
    }

    static final Object[][] contents =
    {
        {"greetings", "\u4F60\u597D\u3002"},
        {"farewell", "\u518D\u89C1\u3002"},
        {"inquiry", "\u4F60\u597D\u5417?"}
    } ;
}

CLASSPATH

ResourceBundle backed up by only Properties Files:

jar -cvf TestI18NResourceBundle.jar com\mot\TestI18N\ResourceBundle\*.properties

ResourceBundle backed up by only Class Files:

javac com\mot\TestI18N\ResourceBundle\*.java
jar -cvf TestI18NResourceBundle.jar com\mot\TestI18N\ResourceBundle\*.class

ResourceBundle backed up by both Class Files and Properties Files:

javac com\mot\TestI18N\ResourceBundle\*.java
jar -cvf TestI18NResourceBundle.jar com\mot\TestI18N\ResourceBundle\*.properties com\mot\TestI18N\ResourceBundle\*.class

Create an I18N object

String language = "en" ;
String country = "US" ;
String strResourceBundlePath = "com.mot.TestI18N.ResourceBundle.MessagesBundle" ;

I18N i18n = new I18N( language, country, strResourceBundlePath ) ;

It will set the current Locale and create the ResourceBundle via the getBundle method which first looks for a class file that matches the base name and the Locale. If it can't find a class file, it then checks for properties files.

When the getBundle method locates the correct class file, it returns a ListResourceBundle object containing the key-value pairs from the class file.

When the getBundle method locates the correct properties file, it returns a PropertyResourceBundle object containing the key-value pairs from the properties file.

Fetch the Localized Text

i18n.getResourceBundle().getString( "greetings" ) ;
i18n.getResourceBundle().getString( "farewell" ) ;
i18n.getResourceBundle().getString( "inquiry" ) ;

The String returned by getString corresponds to the key specified. The String is in the proper language, provided that a class or properties file exists for the specified Locale.

Format Numbers, Currencies, Percentages, Dates, Times, Dates and Times

I18N API documentation

UnicodeFormatter Class

Numeric Character References

HTML

WML

Before getNumericCharacterReferences method After getNumericCharacterReferences method

Hello. Hello.

你好。 你好。

Examples

// Format Number
UnicodeFormatter.getNumericCharacterReferences( i18n.formatNumber( new Integer( 123456 ) ) ) ;
UnicodeFormatter.getNumericCharacterReferences( i18n.formatNumber( new Double( 345987.246 ) ) ) ;

// Format Currency
UnicodeFormatter.getNumericCharacterReferences( i18n.formatCurrency( new Double( 9876543.21 ) ) ) ;

// Format Percent
UnicodeFormatter.getNumericCharacterReferences( i18n.formatPercent( new Double( 0.75 ) ) ) ;

// Format Date
UnicodeFormatter.getNumericCharacterReferences( i18n.formatDate( new Date(), DateFormat.DEFAULT ) ) ;

// Format Time
UnicodeFormatter.getNumericCharacterReferences( i18n.formatTime( new Date(), DateFormat.DEFAULT ) ) ;

// Format Date and Time
UnicodeFormatter.getNumericCharacterReferences( i18n.formatDateTime( new Date(), DateFormat.DEFAULT, DateFormat.DEFAULT ) ) ;

Last updated on Sunday, 06 January 2002

Please send all mails to wailian@singnet.com.sg or wailian@pmail.ntu.edu.sg

Before getNumericCharacterReferences method	After getNumericCharacterReferences method
Hello.	Hello.
你好。	你好。