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Access caller locales and time zones

Perform this task to access elements of the caller internationalization context.

An application component must first resolve a reference to the CallerInternationalization object and then bind it to the Internationalization interface.

Every remote invocation of an application component has an associated caller internationalization context associated with the thread running that invocation. A caller context is propagated by the internationalization service and middleware to the target of a request, such as an EJB business method or servlet service method. This task also applies to Web service client programs.

  1. Obtain the desired caller context elements.
    java.util.Locale [] myLocales  = null;
    try {
      myLocales  = callerI18n.getLocales();
    }
    catch (IllegalStateException ise) {
      // The Caller context is unavailable; 
      // is the service started and enabled?  
    }
    ...

    The Internationalization interface contains the following methods to get caller internationalization context elements:

    • Locale [] getLocales() Returns the list of caller locales associated with the current thread.

    • Locale getLocale() Returns the first in the list of caller locales associated with the current thread.

    • TimeZone getTimeZone() Returns the SimpleTimeZone caller that is associated with the current thread.

    The Internationalization interface supports read-only access to internationalization context within application components. Methods of the Internationalization interface are available to all EJB application components and are used in the same manner for each, but the method semantics vary according to the component type. For instance, when obtaining the caller locale within an EJB client application, the interface returns the default locale of the host Java virtual machine (JVM); in contrast, when obtaining caller context within a servlet service method (for example, doPost or doGet methods), the interface returns the first locale (accept-language) propagated within the corresponding HTML request. See Internationalization context for a discussion of how the service propagates internationalization context throughout an application.

  2. Use the caller context elements to localize computations under a locale or time zone of the calling process.
    DateFormat df = DateFormat.getDateInstance(myLocale);
    String localizedDate = df.getDateInstance().format(aDateInstance);
    ...


Related concepts

  • Internationalization context


    Related tasks

  • Gaining access to the internationalization context API
  • Access invocation locales and time zones

  • Internationalization context API: Programming reference