STRUTS INTERNATIONALIZATION

In this tutorial we shall see how to implement Internationalization (abbreviated as I18N) in Struts.

STRUTS INTERNATIONALIZATION

STRUTS INTERNATIONALIZATION
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by Farihah Noushene B.E.
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(published in Developer IQ - Oct 2005)

     

In this tutorial we shall see how to implement Internationalization (abbreviated as I18N) in Struts.

The Multinational Corporations have their branches in various parts of the world. so, they must provide products and services to their clients and customers in their traditional way. The customers will expect the product to work in their native languages especially the date, time, currency etc.,. So, the we should not make any assumptions about their clients region or language. If such assumptions become invalid, we have to re-engineer the applications.

Internationalization or I18N is the process of designing the software to support multiple languages and regions, so that we don't need to re-engineer the applications every language or country needs to be supported.

Struts provides various locale sensitive JSP tags which can be used to make the applications simpler. With this short introduction we shall see how to implement i18n in a Simple JSP file of Struts.

g:\>md localedemo
g:\>cd localedemo
g:\localedemo>edit localedemo.jsp

// g:\localedemo\localedemo.jsp

<%@ page language="java" %>

<%@ taglib uri="/WEB-INF/struts-html.tld" prefix="html" %>
<%@ taglib uri="/WEB-INF/struts-bean.tld" prefix="bean" %>
<%@ taglib uri="/WEB-INF/struts-logic.tld" prefix="logic" %>

<html:html locale="true">
<body bgcolor=pink>

<bean:message key="index.info" />

</body>
</html:html>
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Next copy struts-blank.war to f:\tomcat41\webapps and start the tomcat with JAVA_HOME as jdk1.4. A folder named struts-blank will be created. Rename the folder as localedemo. Copy the above JSP file to f:\tomcat41\webapps\localedemo.

Now we have to edit the property files for various locales. The struts framework(struts1.1) provides a property file named application.properties. It is present in the folder f:\tomcat41\webapps\localedemo\web-inf\classes\resources. We have to add our own property file in this folder only. Our property file much be named along with the language code

For example the language code of
  
1. German - de
   2. Spanish - es
   3. English - en
   4. Korean - ko
   5. French - fr
   6. Italy - it

So, when we write i18n message in German language it must be placed in property file named application_de.properties and all the properties files must be present in the resources folder only. Also when we write the property file of a particular language it need not be of the same language. For example we can create application_de.properties and write the message in french or english. In fact, the message does not depend on any language. It is a simple key value pair. The message we give for the key is just substituted. The property file to locate the value of key depends on the language settings of the browser. For this example, we will write four properties file as follows.

f:\tomcat41\webapps\localedemo\web-inf\classes\resources\ application_de.properties

index.info=GERMANY
---------------------------------------------------------
f:\tomcat41\webapps\localedemo\web-inf\classes\resources\ application_es.properties

index.info=SPAIN
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f:\tomcat41\webapps\localedemo\web-inf\classes\resources\ application_en.properties

index.info=ENGLISH
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f:\tomcat41\webapps\localedemo\web-inf\classes\resources\ application_fr.properties

index.info=FRANCE
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Also append this text in the application.properties file
  index.info=STRUTS TUTORIAL.

Now we have to add entry in the
struts-config.xml file for all the properties files. The entry and its corresponding portion is shown below.

<!-- Message Resources Definitions -->

  <message-resources parameter="resources.application_fr"/>
  <message-resources parameter="resources.application_es"/>
  <message-resources parameter="resources.application_en"/>
  <message-resources parameter="resources.application_de"/>
  <message-resources parameter="resources.application"/>

Now restart the Tomcat server. Open the Internet Explorer and type the URL as http://localhost:8080/localedemo/localedemo.jsp. We will get the message 'ENGLAND'. This is because our default browser language is 'United States English'.

Now we have to change the language settings of the browser to change the locale. For that, Open a new Internet Explorer, goto 'Tools' menu and select the 'Internet Options'. In the 'Internet Option' dialog box, select 'General' tab and click the 'Languages...' button. We will get 'Language Preference' dialog box. There click 'Add...' button and add the languages. For this example add English, Spanish, German and French. Here we have languages specific to particular region. For example we have, French Belgium, French Canada, French France etc., we can select any one of these in all cases. Next select 'German' and by using the 'Move up' button, place it on the top. Now type the URL as http://localhost:8080/localedemo/localedemo.jsp. We will get the message 'GERMAN' Similarly place 'Spanish' and 'French' at the top, we will get the message 'SPAIN' and 'FRANCE' respectively.
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