Internationalization Tags

<fmt:message>

https://jakarta.ee/specifications/tags/2.0/jakarta-tags-spec-2.0.html#fmtmessage

https://jakarta.ee/specifications/tags/2.0/jakarta-tags-spec-2.0.html#fmt:message

<fmt:setLocale value="en_US" />

https://jakarta.ee/specifications/tags/2.0/jakarta-tags-spec-2.0.html#i18n-localization-context

https://jakarta.ee/specifications/tags/2.0/jakarta-tags-spec-2.0.html#preferred-locales

Resolves a localized message in a resource bundle to display it inline or saves it to a variable , the key specifies the key to resolve to display.

related to local is the Resource Bundle

<fmt:bundle>

https://jakarta.ee/specifications/tags/2.0/jakarta-tags-spec-2.0.html#fmt:bundle

Explains and expands on how to use the optional bundle attribute that indicates which localization context can be used including

<fmt:setBundle>

https://jakarta.ee/specifications/tags/2.0/jakarta-tags-spec-2.0.html#fmt:setBundle

<fmt:timeZone>

https://jakarta.ee/specifications/tags/2.0/jakarta-tags-spec-2.0.html#fmt:timeZone

<fmt:setTimeZone>

https://jakarta.ee/specifications/tags/2.0/jakarta-tags-spec-2.0.html#fmtsettimezone

<fmt:formatNumber>

https://jakarta.ee/specifications/tags/2.0/jakarta-tags-spec-2.0.html#fmtformatnumber

<fmt:formatDate>

https://jakarta.ee/specifications/tags/2.0/jakarta-tags-spec-2.0.html#fmtformatdate

Putting Internationalization Library Tags to Use

Our FMT Library Examples

Charity Address book - we expand on the Charity Registration Example that where we introduced Core Tag Library examples:

first we expand on our web.xml by adding the following context initialization parameter

<context-param>
    <param-name>javax.servlet.jsp.jstl.fmt.localizationContext</param-name>
    <param-value>CharityAddressBook-messages</param-value>
</context-param>

https://github.com/NicorDesignsLLC/JakartaJEEWebDevelopment/blob/jee8web-jstl-part2/charity-registration/src/main/webapp/WEB-INF/web.xml

this helps to establish a resources bundle that will be used to store all the localized language messages

The container (Tomcat 9) in our case looks for the resource bundle anywhere on our Java Class Path of our web application with the following name:

CharityAddressBook-messages_[language]_[region].properties

if it does not find that it looks for

CharityAddressBook-messages_[language].properties

and finally if that is not found it switches to a fall back locale US English in my case

In our case we will follow the option of Maven convention over configuration and place our resource bundle file in the src/main/resources directory

CharityAddressBook-messages_en_US.properties

these files should then be copied to the class path locations during our Maven Build

We add the CharityRegistrationAddressListServlet to use the new language option as follows:

https://github.com/NicorDesignsLLC/JakartaJEEWebDevelopment/blob/jee8web-jstl-part2/charity-registration/src/main/java/com/nicordesigns/CharityRegistrationAddressListServlet.java

Then we update the index.jsp with a new re-direct and the base.jspf with the new i8n taglib directive

https://github.com/NicorDesignsLLC/JakartaJEEWebDevelopment/blob/jee8web-jstl-part2/charity-registration/src/main/webapp/WEB-INF/jsp/base.jspf

and we add the listRegistrationAddresses.jsp for internationalization of text and formatting of the dates

https://github.com/NicorDesignsLLC/JakartaJEEWebDevelopment/blob/jee8web-jstl-part2/charity-registration/src/main/webapp/WEB-INF/jsp/view/listRegistrationAddresses.jsp

we will compile and run our webapp and have a look at it:

http://localhost:8080/charity-registration/charityRegistrationAddressListServlet

and

http://localhost:8080/charity-registration/charityRegistrationAddressListServlet?language=afrikaans

http://localhost:8080/charity-registration/charityRegistrationAddressListServlet?language=afrikaans&empty