❮ Jstl Core Redirect Tag Jstl Format Formatnumber Tag ❯

JSP Internationalization

Before starting, it is necessary to explain several important concepts:

Internationalization (i18n): Indicates that a page presents different translated versions based on the visitor's language or country.
Localization (l10n): Adding resources to a website to make it suitable for different regions and cultures. For example, an Indian language version of the website.
Locale: This is a specific region or culture, usually considered as a combination of a language tag and a country tag connected by an underscore. For example, "en_US" represents the American English locale.

If you want to build a global website, you need to care about a series of items. This chapter will detail how to handle internationalization issues and provide some examples to deepen understanding.

The JSP container can provide the correct page version based on the locale attribute of the request. The following syntax shows how to obtain the Locale object through the request object:

java.util.Locale request.getLocale()

Detecting Locale

The table below lists some important methods of the Locale object, used to detect the region, language, and locale of the request object. All these methods will display the country name and language name in the browser:

Number	Method & Description
1	String getCountry() Returns the uppercase English country/region code, or the ISO 3166 2-letter format locale
2	String getDisplayCountry() Returns the country name to be displayed to the user
3	String getLanguage() Returns the lowercase English language code, or the ISO 639 format locale
4	String getDisplayLanguage() Returns the language name to be displayed to the user
5	String getISO3Country() Returns the 3-letter abbreviation of the country name
6	String getISO3Language() Returns the 3-letter abbreviation of the language name

Example Demonstration

This example shows how to display the language and country in JSP:

<%@ page import="java.io.*,java.util.Locale" %>
<%@ page import="javax.servlet.*,javax.servlet.http.* "%>
<%
   // Get client locale information
   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>

Language Setting

JSP can output a page using Western European languages, such as English, Spanish, German, French, Italian, and so on. Therefore, it is important to set the Content-Language header to correctly display all characters.

Secondly, it is necessary to use HTML character entities to display special characters, such as "ñ" for ñ, and "¡" for ¡:

<%@ 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 Espa?ol";

%>
<html>
<head>
<title><%  out.print(title); %></title>
</head>
<body>
<center>
<h1><%  out.print(title); %></h1>
</center>
<div align="center">
<p>En Espa?ol</p>
<p>?Hola Mundo!</p>
</div>
</body>
</html>

Locale-Specific Date

English: This is a Chinese to English translation. Please provide the English translation for this text. Do not provide any explanations or text apart from the translation.

Chinese: 可以使用java.text.DateFormat类和它的静态方法getDateTimeInstance()来格式化日期和时间。接下来的这个例子显示了如何根据指定的区域来格式化日期和时间：

<%@ 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>

区域特定货币

可以使用java.text.NumberFormat类和它的静态方法getCurrencyInstance()来格式化数字。比如在区域特定货币中的long型和double型。接下来的例子显示了如何根据指定的区域来格式化货币：

<%@ 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>

区域特定百分比

可以使用java.text.NumberFormat类和它的静态方法getPercentInstance()来格式化百分比。接下来的例子告诉我们如何根据指定的区域来格式化百分比：

<%@ 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);

Locale-Specific Dates

You can use the java.text.DateFormat class and its static method getDateTimeInstance() to format dates and times. The following example shows how to format dates and times according to a specified 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>

Locale-Specific Currency

You can use the java.text.NumberFormat class and its static method getCurrencyInstance() to format numbers, such as long and double types in locale-specific currency. The following example shows how to format currency according to a specified 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>

Locale-Specific Percentage

You can use the java.text.NumberFormat class and its static method getPercentInstance() to format percentages. The following example shows how to format percentages according to a specified 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);

<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>
</div>
</body>
</html>

❮ Jstl Core Redirect Tag Jstl Format Formatnumber Tag ❯