Multilingual Web Applications With JavaJ2EE

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Multilingual Web Applications With Java/J2EE

• Presented by Jason Shepherd
• Bass and Associates, Inc., a HunTel Company
• 12-Oct-2005, 1130 AM
• ITEC 2005, HyVee Hall, Des Moines, Iowa

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First, our apologies Our initial presenters,
internationalization experts, and design
leads Napolean Dynamite and Pedro Sanchez are
unable to attend. Theyre off building a cake, or
something. So youre stuck listening to me.
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Outline

• Bass and Associates, Inc.
• Why Internationalization
• What is Internationalization?
• Goals
• Technical Design and Common Issues
• J2EE
• XSLT (optional)
• The Process of Internationalization

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Bass and Associates

• Bass consultants lead an Internationalization
  effort of an automotive delivery logistics
  application for one of the Big Three car
  manufacturers
• Initial implementation offered application in
  both US English and Mexico Spanish
• Currently in planning phase for Canada French and
  Germany German

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Why Internationalization?

• Hard to do business in a global marketplace if
  you cant speak the users language (or
  languages)
• Good strategy for sales/marketing
• Broadens spectrum of potential customers

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But what is Internationalization?
You keep using that word. I do not think it
means what you think it means.
The Princess Bride, 20th Century Fox, 1987
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What is Internationalization?

• process of creating an application so it can be
  adapted to different languages and countries
  without coding changes
• also known as i18n (since there are 18
  characters between the i and n)

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What is Internationalization?

• Characteristics of an i18n application
• By adding localized text, the app can display
  information in any language/country
• Textual elements are not hard-coded they are
  stored externally and retrieved at run-time

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What is Internationalization?

• Characteristics of an i18n application (cont)
• Support for new languages/countries does not
  require re-compilation
• Culturally dependent data (dates, currencies,
  etc.) conforms to users language/country
• Can be localized quickly

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Localization

• process of adapting software for a specific
  language/country by adding locale-specific
  components and text translations
• sometimes abbreviated as l10n (10 letters between
  L and N)

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Localizing an Application

• text translation is the most time-consuming phase
  of l10n (the human element)
• sounds and images may need localized if they are
  culturally sensitive (red indicates danger in
  the US, but in some countries it means purity
  likewise the icon of a mailbox isnt familiar
  outside the U.S., and instead a mail envelope
  icon should be used)
• formatting of numbers, dates, and currencies
• may impact the UI layout strategy

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Locale

• Users locale is the object central to l10n
• political, cultural, and region-specific elements
  (for Java-based applications, expressed as a
  language code and country code)

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Locale (cont)

• has the form xx_YY
• xx is 2-character language code (ISO-639)
• YY is 2-character country code (ISO-3166)
• Examples
• en_US - United States English
• en_GB - Great Britain English
• es_MX - Mexico Spanish (Espanol)

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Design Goals
One of my goals is to have sweet tetherball
skills.
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Design Goals

• Create framework for rapid adoption of new
  languages/regions
• framework should have negligible impact on
  performance and resources
• framework should scale in terms of
• of locales, of users, content size
• framework should be easy to maintain
• translations should be centralized
• future content/functionality must be i18n

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Technical Design
Finally the cool stuff. I love technology.
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Example Web Tier(prior)
HTTP request
ActionServlet
CredentialsFilter
To Service Tier
HTTP response
HTTP response
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i18n for J2EE Apps

• Locale stored in HTTP session
• Resource bundles stored in properties files told
  to load in web.xml
• Access locale-specific messages in the Web tier
  using tag libraries
• Struts tag libraries versus JSTL
• Access locale-specific messages elsewhere using
  custom code
• Locale-specific messages for XSLT

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The Locale Object

• java.util.Locale
• Locale locale new Locale(en, US)
• session.setAttribute(org.apache.struts.action.Acti
  on.LOCALE_KEY, locale)

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Properties Files

• Plain text file
• Will reside in classpath
• One file for each locale (filename convention)
• When paired with a locale, the closest matching
  file will be selected

MyApp.properties MyApp_en.properties MyApp_en_US.p
roperties MyApp_es_MX.properties
default
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Properties Files (cont)

• Creating properties files (cont)

MyApp_en_US.properties
greetings Hello. farewell Goodbye. inquiry
How are you?
MyApp_fr_FR.properties
greetings Bonjour. farewell Au
revoir. inquiry Comment allez-vous?
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Properties Files (cont)

• Ensure your properties files are visible on the
  classpath
• make sure your build process (e.g. Apache Ant) is
  grabbing the properties files and putting them in
  the proper location
• must be placed somewhere that all classes will be
  able to find it (e.g. a library jar file or
  possibly in the WAR file under WEB-INF/classes)

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Side Notes

• Properties files and resource bundle keys should
  follow human-readable naming conventions (not
  key1, key2, etc.)
• IDEs dont help much here
• Our convention
• general.vin, general.railcar
• vehicleTrace.dealerName
• netMap.critAlert

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J2EE (w/ Struts)

• Configure web.xml to load the properties files

action
org.apache.struts
.action.ActionServlet
applicationme MyApp

locale
true
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JSP (w/ Struts)

• Accessing the resource bundles in a JSP
• First, include the Struts bean tag library
• prefix"bean"
• Then, replace any hard-coded messages
• Hello

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JSP Side Notes

• Properties files can be HTML escape encoded
  (aacute) or Unicode encoded (\u0000) Struts
  taglibs are encoding-aware
• The content type in your resulting HTML page must
  be set correctly (content type tells browser what
  character set youre using)

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J2EE

• Accessing outside of a JSP context
• UI utility classes or custom taglibs
• We wrote a utility class to load the properties
  files and retrieve messages

Locale locale (Locale) session.getAttribute(org.
apache.struts.action.Action.LOCALE_KEY) String
message ResourceBundleUtil.getMessage( locale,
hello.message) this class comes in handy
when we try to i18n our XSLT stylesheets stay
tuned!
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Design Issue The Database Temptation

• JSTL and Struts Taglibs dont support access to
  localized content in a database (would have to
  rewrite Struts or create custom solution)
• If DB is shared between applications, all
  applications using the DB must be i18n-enabled
• DB must be Unicode-enabled and have plenty of
  extra disk space

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Design Issue The Database Temptation

• Requires more database accesses
• Very bad for high volume sites where database
  connections must be managed carefully
• Issue of scale
• Might require complex joins in a normalized DB
  schema

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Design Issue Assigning a Users Locale

• Accepted languages HTTP header (set in browser
  preferences)
• Little/no control over available languages
• User still might want to change language
• Cookie
• Works with both static and dynamic sites
• Store locale in DB
• Retrieve users locale when user first logs in
• Only works for dynamic site

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Design Issue Other Information

• References to other static content must be
  localized too
• Suggest placing images, JavaScript, etc., in
  separate content directories for each locale
• Then, use scriptlets or taglibs to access content

/im/header.gif
/
locale /js/errorMessages.js
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Design Issue UI Layout

• Widths and heights of screen elements may be
  impacted
• Railcar Trace
• Rastreo des Plataformas
• Need obvious way to change language
• Language names should be in their native language
• e.g., Espanol, not Spanish

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Internationalization in XSLT

• Some J2EE applications deliver their data to the
  Web tier as XML and then render the UI using XSLT
  (or a combination of JSP and XSLT)
• We have resource bundles all nice and neat, but
  no way to access them in XSLT

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XSLT

• Different approaches to i18n in this case
• Option 1 Not try to use properties files
  instead, make a separate XSLT stylesheet for each
  locale (yuck! Must be maintained and manually
  synchronized with the properties files)
• Option 2 Write code to insert the locale into
  the stylesheet as an XSL variable. Then use Java
  from within your stylesheet to extract the
  resource bundle messages (Xalan-Java extensions)

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XSLT

• XSLT stylesheets can be localized the same way
  JSPs are.
• But, XSLT stylesheets don't have access to the
  Java HTTP session object that stores the users
  locale information
• The locale must be inserted into the XSLT and
  passed to the Xalan-Java objects

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XSLT An i18n (not l10n yet) Stylesheet
tml" xmlnsxsl"http//www.w3.org/1999/XSL/Trans
form" xmlnsinl"http//www.insightnl.com" xmlns
message"http//xml.apache.org/xalan/java/com.upr
r.app.inl.util.ResourceBundleUtil"
version"0.1" select"messagegetMessage(locale,hello.message
)"/
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XSLT Retrieving the Stylesheet and Inserting the
Locale
Note we store our XSLT in the DB
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XSLT Retrieving the Stylesheet and Inserting the
Locale
This XSLT is applied to an i18n XSLT to create a
L10n XSLT. The locale is extracted from the
session and inserted into a StringBuffer using a
Java utility class in the Web tier.
i18n XSLT
locale insert XSLT
l10n XSLT
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Example Web Tier(after i18n changes)
HTTP request
ActionServlet
CredentialsFilter
To Service Tier
HTTP response
Struts tags
Resource Bundles
HTTP response
MyApp.properties
Xalan-Java
ResourceBundleUtil
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The Process of i18n

• i18n (create properties files and remove
  hard-coded values)
• Send translations to translators
• Receive translations and perform l10n
• Deploy and have customers acceptance test

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Recap

• i18n, l10n
• Goals Business Needs, Scalability,
  Maintainability
• Technical Design J2EE Web Tier and XSLT
• The Process of Internationalization

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Questions?
I hope all of your wildest dreams of
internationalizing your app come true. Lucky!
Thank you for attending! Jason
Shepherd jshepherd_at_bass-inc.com 402-346-1505