JSP - Internationalization| i18n| l10n

In this chapter, we will discuss the concept of Internationalization in JSP. Before we proceed, let us understand the following three important terms −
Internationalization (i18n) − This means enabling a website to provide different versions of content translated into the visitor's language or nationality.
Internationalization (i18n) − This means enabling a website to provide different versions of content translated into the visitor's language or nationality.
Localization (l10n) − This means adding resources to a website to adapt it to a particular geographical or cultural region for example Hindi translation to a web site.
Localization (l10n) − This means adding resources to a website to adapt it to a particular geographical or cultural region for example Hindi translation to a web site.
locale − This is a particular cultural or geographical region. It is usually referred to as a language symbol followed by a country symbol which are separated by an underscore. For example, "en_US" represents english locale for US.
locale − This is a particular cultural or geographical region. It is usually referred to as a language symbol followed by a country symbol which are separated by an underscore. For example, "en_US" represents english locale for US.
There are a number of items which should be taken care of while building up a global Website. This tutorial will not give you complete detail on this but it will give you a good example on how you can offer your Webpage in different languages to the internet community by differentiating their location, i.e., locale.
A JSP can pick up appropriate version of the site based on the requester's locale and provide appropriate site version according to the local language, culture and requirements. Following is the method of request object which returns the Locale object.
java.util.Locale request.getLocale() 

Following are the important locale methods which you can use to detect requester's location, language and of course locale. All the below methods display the country name and language name set in the requester's browser.
String getCountry()
This method returns the country/region code in upper case for this locale in ISO 3166 2-letter format.
String getDisplayCountry()
This method returns a name for the locale's country that is appropriate for display to the user.
String getLanguage()
This method returns the language code in lower case for this locale in ISO 639 format.
String getDisplayLanguage()
This method returns a name for the locale's language that is appropriate for display to the user.
String getISO3Country()
This method  returns a three-letter abbreviation for this locale's country.
String getISO3Language()
This method returns a three-letter abbreviation for this locale's language.
The following example shows how to display a language and associated country for a request in a JSP −
<%@ page import = "java.io.*,java.util.Locale" %>
<%@ page import = "javax.servlet.*,javax.servlet.http.* "%>
<%
   //Get the client's Locale
   Locale locale = request.getLocale();
   String language = locale.getLanguage();
   String country = locale.getCountry();
%>

<html>
   <head>
      <title>Detecting Locale</title>
   </head>

   <body>
      <center>
         <h1>Detecting Locale</h1>
      </center>
      
      <p align = "center">
         <% 
            out.println("Language : " + language  + "<br />");
            out.println("Country  : " + country   + "<br />");
         %>
      </p>
   </body>
</html>
A JSP can output a page written in a Western European language such as English, Spanish, German, French, Italian, Dutch etc. Here it is important to set Content-Language header to display all the characters properly.
Another important point is to display all the special characters using HTML entities; for example, "&#241;" represents "ñ", and "&#161;" represents "¡" as follows −
<%@ page import = "java.io.*,java.util.Locale" %>
<%@ page import = "javax.servlet.*,javax.servlet.http.* "%>

<%
   // Set response content type
   response.setContentType("text/html");
   
   // Set spanish language code.
   response.setHeader("Content-Language", "es");
   String title = "En Español";
%>

<html>
   <head>
      <title><%  out.print(title); %></title>
   </head>
   
   <body>
      <center>
         <h1><%  out.print(title); %></h1>
      </center>
      
      <div align = "center">
         <p>En Español</p>
         <p>¡Hola Mundo!</p>
      </div>
   </body>
</html>
You can use the java.text.DateFormat class and its static getDateTimeInstance( ) method to format date and time specific to locale. Following is the example which shows how to format dates specific to a given locale −
<%@ page import = "java.io.*,java.util.Locale" %>
<%@ page import = "javax.servlet.*,javax.servlet.http.* "%>
<%@ page import = "java.text.DateFormat,java.util.Date" %>

<%
   String title = "Locale Specific Dates";
   
   //Get the client's Locale
   Locale locale = request.getLocale( );
   
   String date = DateFormat.getDateTimeInstance(
      DateFormat.FULL, 
      DateFormat.SHORT, 
      locale).format(new Date( ));
%>

<html>
   
   <head>
      <title><% out.print(title); %></title>
   </head>
   
   <body>
      <center>
         <h1><% out.print(title); %></h1>
      </center>
      
      <div align = "center">
         <p>Local Date: <%  out.print(date); %></p>
      </div>
   </body>
</html>
You can use the java.txt.NumberFormat class and its static getCurrencyInstance( ) method to format a number, such as a long or double type, in a locale specific curreny. Following is the example which shows how to format currency specific to a given locale −
<%@ page import = "java.io.*,java.util.Locale" %>
<%@ page import = "javax.servlet.*,javax.servlet.http.* "%>
<%@ page import = "java.text.NumberFormat,java.util.Date" %>

<%
   String title = "Locale Specific Currency";
   
   //Get the client's Locale
   Locale locale = request.getLocale( );
   
   NumberFormat nft = NumberFormat.getCurrencyInstance(locale);
   String formattedCurr = nft.format(1000000);
%>

<html>
   
   <head>
      <title><% out.print(title); %></title>
   </head>
   
   <body>
      <center>
         <h1><% out.print(title); %></h1>
      </center>
      
      <div align = "center">
         <p>Formatted Currency: <%  out.print(formattedCurr); %></p>
      </div>
   </body>
</html>
You can use the java.txt.NumberFormat class and its static getPercentInstance( ) method to get locale specific percentage. Following example shows how to format percentage specific to a given locale −
<%@ page import = "java.io.*,java.util.Locale" %>
<%@ page import = "javax.servlet.*,javax.servlet.http.* "%>
<%@ page import = "java.text.NumberFormat,java.util.Date" %>

<%
   String title = "Locale Specific Percentage";
   
   //Get the client's Locale
   Locale locale = request.getLocale( );
   
   NumberFormat nft = NumberFormat.getPercentInstance(locale);
   String formattedPerc = nft.format(0.51);
%>

<html>
   
   <head>
      <title><% out.print(title); %></title>
   </head>
   
   <body>
      <center>
         <h1><% out.print(title); %></h1>
      </center>
      
      <div align = "center">
         <p>Formatted Percentage: <%  out.print(formattedPerc); %></p>