A Struts 2 internationalizing(i18n), localization(i10n) or multi-lingua example to show the use of resource bundle to display the message from different languages. In this example, you will create a simple login screen, display the message from resource bundle via the Struts 2 UI components, and change the locale base on the selected language option.

Download It – Struts2-i18-localization-Example.zip

1. Project Structure

The project structure for this example

Struts2 localization folder structure

2. Properties file

Make sure the properties file are named as country specified code.

In some “non-Europe” or “non-English” like characters, you should always encode the content with native2ascii tool.

global.properties


#Global messages
global.username = Username
global.password = Password
global.submit = Submit

global_zh_CN.properties


#Global messages
global.username = \u7528\u6237\u540d
global.password = \u5bc6\u7801
global.submit=\u63d0\u4ea4

global_fr.properties


#Global messages
global.username = Nom d'utilisateur
global.password = Mot de passe
global.submit = Soumettre

global_de.properties


#Global messages
global.username = Benutzername
global.password = Kennwort
global.submit = Einreichen
Please read this Struts 2 resource bundle example to understand how Struts 2 search the properties file automatically.

3. Action

Two action classes, the LocaleAction is basically do nothing, and the LoginAction will do a simple validation and display the error message from resource bundle via getText().

LocaleAction.java


package com.mkyong.common.action;

import com.opensymphony.xwork2.ActionSupport;

public class LocaleAction extends ActionSupport{

	//business logic
	public String execute() {
		return "SUCCESS";
	}
}

LoginAction.java


package com.mkyong.user.action;

import com.opensymphony.xwork2.ActionSupport;

public class LoginAction extends ActionSupport{

	private String username;
	private String password;
	 
	//...getter and setter methods

	//business logic
	public String execute() {
		return "SUCCESS";
	}

	//simple validation
	public void validate(){
		if("".equals(getUsername())){
			addFieldError("username", getText("username.required"));
		}
		if("".equals(getPassword())){
			addFieldError("password", getText("password.required"));
		}
	}
}

4. View page

A login page with a textbox, password and submit UI components.

To support Struts 2 localization, you HAVE TO declared the <%@ page contentType=”text/html;charset=UTF-8″ %> in your view page, else you will have problem to display the “UTF-8 data” correctly, especially the Chinese characters. Read this article about Struts 2 Chinese localization issue.

login.jsp


<%@ page contentType="text/html;charset=UTF-8" %>
<%@ taglib prefix="s" uri="/struts-tags" %>
<html>
<head>
</head>

<body>
<h1>Struts 2 localization example</h1>

<s:form action="validateUser" namespace="/user">

	<s:textfield key="global.username" name="username" />
	<s:password key="global.password" name="password"/>	
	<s:submit key="global.submit" name="submit" />
	
</s:form>

<s:url id="localeEN" namespace="/" action="locale" >
   <s:param name="request_locale" >en</s:param>
</s:url>
<s:url id="localezhCN" namespace="/" action="locale" >
   <s:param name="request_locale" >zh_CN</s:param>
</s:url>
<s:url id="localeDE" namespace="/" action="locale" >
   <s:param name="request_locale" >de</s:param>
</s:url>
<s:url id="localeFR" namespace="/" action="locale" >
   <s:param name="request_locale" >fr</s:param>
</s:url>

<s:a href="%{localeEN}" >English</s:a>
<s:a href="%{localezhCN}" >Chinese</s:a>
<s:a href="%{localeDE}" >German</s:a>
<s:a href="%{localeFR}" >France</s:a>
 
</body>
</html>
To change the default locale, you just need to declared a “request_locale” parameter, set your prefer language code and pass to an Action class. In Struts 2 the com.opensymphony.xwork2.interceptor.I18nInterceptor interceptor, which declared in the struts-default.xml, will hijack your Action class and handle the locale stuff accordingly.

5. Display the resource bundle message?

In Struts 2 , there are many ways to display the resource bundle message base on the selected language or locale. For examples, 


<s:textfield key="global.username" name="username" />
<s:text name="global.username" />	
<s:property value="getText('global.username')" />
<s:text name="global.password" />
In Struts 1, there are one standard bean:message to display the resource bundle message, which is more prefer. But in Struts 2, there are so many equivalent ways to display the resource bundle message (even internal work is different), it’s quite confuse at the first glance. Basically, no matter what you choose, Struts 2 also will display the resource bundle message correctly.

6. struts.xml

Struts 2 configuration file, link it all together.


<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
"http://struts.apache.org/dtds/struts-2.0.dtd">
 
<struts>

	<constant name="struts.custom.i18n.resources" value="global" />
 	<constant name="struts.devMode" value="true" />
 	
	<package name="user" namespace="/user" extends="struts-default">
	   <action name="login">
		<result>pages/login.jsp</result>
	   </action>
	   <action name="validateUser" class="com.mkyong.user.action.LoginAction">
		<result name="SUCCESS">pages/welcome.jsp</result>
		<result name="input">pages/login.jsp</result>
	   </action>
	</package>
	
	<package name="default" namespace="/" extends="struts-default">
	   <action name="locale" class="com.mkyong.common.action.LocaleAction">
		<result name="SUCCESS">user/pages/login.jsp</result>
	   </action>
	</package>
	
</struts>

7. Demo

http://localhost:8080/Struts2Example/user/login.action
http://localhost:8080/Struts2Example/locale.action?request_locale=en

Struts2 localization english

http://localhost:8080/Struts2Example/locale.action?request_locale=zh_CN

Struts2 localization chinese

http://localhost:8080/Struts2Example/locale.action?request_locale=de

Struts2 localization German

http://localhost:8080/Struts2Example/locale.action?request_locale=fr

Struts2 localization France

Reference

  1. http://struts.apache.org/2.1.8/docs/localization.html
  2. http://www.mkyong.com/java/java-convert-chinese-character-to-unicode-with-native2ascii/
  3. http://www.mkyong.com/struts2/struts-2-resource-bundle-example/
  4. http://www.mkyong.com/struts/struts-internationalizing-or-localization-example/