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General Points of Internationalization Programming
Server Side Programming

1. Awareness Of User Locales
   
   Messages, labels, date, currency, and any other culture related information should be shown in accordance to user's language (locale), not server one.
   User locales come to the server in HTTP requests from each browser, so you have to apply them to the server process. You need remember that the normal programming apply the running platform (server OS) locale to the application.
   The following are sample copdes of server process in each programming case.
   
   
   • Resource Loading (messages/labels)
     
     
     • Java (JSP/Servlet)
       

       //Set the default language English.
       java.util.Locale.setDefault(new java.util.Locale("en",""));
       //Load the resource of user language (set by the user's browser).
       java.util.ResourceBundle wwnaviBundle = 
           java.util.ResourceBundle.getBundle("wwnavi_rs",request.getLocale()); 
           //'request' is a predefined variable in JSP, or given as a method paramter in Servlet.
       

   • Date Format
     
     
     • Java (JSP/Servlet)
       

       //Format the current date in user language (set by user's browser).
       DateFormat df = 
          DateFormat.getDateTimeInstance(DateFormat.DEFAULT,DateFormat.DEFAULT,request.getLocale());
           //'request' is a predefined variable in JSP, or given as a method paramter in Servlet.
       String date = df.format(new Date());
       

2. UTF-8 Encoding
   
   For writting Web UI (HTML), to use UTF-8 is recommended.
   Most of web browsers support UTF-8, and the all languages can be output in single encoding.
   The following are sample copdes of server process in each programming case.
   
   
   • Setting Charset UTF-8
     
     
     • Java (JSP/Servlet)
       

       <%@ page contentType="text/html; charset=UTF-8" %> //JSP tag.
       response.setContentType("text/html; charset=UTF-8"); //Servlet code.
       

3. Neutral Format For Data Storing
   
   Date, currency, and other format data need 'some format' when it's stored in strages (e.g. databases), and if you use a 'culture specific' format for it, it means that the data depends on one specific culture. (e.g. If you write codes of storing date values in MySQL supposing that date columns are always Japanese format, your application will not run English setting MySQL.)
   For data stroring, to use ISO standard format is recommended which can be dealed with regardless of language settings.
   The following are sample copdes of server process in each programming case.
   
   
   • Timestamp Handling
     
     
     • Java (JSP/Servlet)
       

       //Keep the timestamp in MySQL in ISO standard format, and show them in user's format.
       
       //The timestamp value in MySQL
       | edit_date         |
        -------------------
        2010-01-25 00:00:00 
       
       //Get the value by SQL.
       String sql = "select edit_date from table1 ...";...
       ResultSet rs = pstmt.executeQuery();...
       Timestamp ts = rs.getTimestamp(0);...
       
       //Parse the value as ISO standard format and create a date object.
       DateFormat df = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss");
       Date date = df.parse(ts.toString());
       
       //Format the date object in user language (set by user's browser).
       DateFormat df = 
          DateFormat.getDateTimeInstance(DateFormat.DEFAULT,DateFormat.DEFAULT,request.getLocale());
           //'request' is a predefined variable in JSP, or given as a method paramter in Servlet.
       out.println(df.format(date));
       

4. UTC And Local Time
   
   The current time given by programming language in the server is based on the server's time zone.
   If you use this time directly, it cannot be handled correctly by the user who uses a different time zone from the server.
   (For example, the time stamp of the data updated at 9 AM on the server in Japan, should be around 8 PM on the previous day in America, because 9 AM in America is around 10 PM in Japan.)
   
   To solve this problem, user UTC (Universal Time, Coordinated) on the server and convert them to user local times based on each time zone.
   
   The following is a sample code of getting the current time as UTC and converting them to local times.
   
   
   • UTC And Local Time Calculation
     
     
     • Java
       

       // Get UTC
       Calendar cal = Calendar.getInstance();
       cal.setTime(new Date());
       
       int offSet = TimeZone.getDefault().getOffset(cal.getTimeInMillis());
       offSet = offSet / 1000;
       cal.add(Calendar.SECOND, -offSet);
       
       Date utcNow = cal.getTime(); 
       
       // Convert UTC to a local time
       cal = Calendar.getInstance();
       cal.setTime(utcNow);
       
       TimeZone locTz = TimeZone.getTimeZone("Asia/Japan"); (*1)
       int offSet = locTz.getRawOffset();
       offSet = offSet / 1000;
       cal.add(Calendar.SECOND, offSet);
       
       if (locTz.inDaylightTime(cal.getTime())) { (*2)
         cal.add(Calendar.SECOND, locTz.getDSTSavings() / 1000);
       }
       
       Date locDate = cal.getTime();
       
       *1)Japanese time zone is specified.
       Actually, you need to detect the right time zone from access area or user settings, 
       but this process needs mapped data between time zone IDs and region specific information.
       
       The list of TimeZone IDs are given by the method, getAvailableIDs.
       
       About client time zone detection,
       refer to JavaScript Internationalization Programming - Locale, Format, And Time Zone.
       
       *2)Checking if the target time zone has summer time.
       

     • .NET(C++, C#, VB)
       

       
       Refer to MSDN Library.
       
       

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