Package oracle.i18n.servlet.localesource

Class LocaleSource

  • All Implemented Interfaces:
    Serializable
    Direct Known Subclasses:
    ApplicationDefault, DBLocaleSource, HttpAcceptLanguage, UserInput
    public abstract class LocaleSource
extends Object
implements Serializable
    The LocaleSource class is the abstract base class for locale source objects. A locale source represents an entity that can provide certain locale specific preferences like a locale name, encoding name, etc. There can be many types of sources of pertinent locale preferences, for instance a database table can contain locale specific parameters and can be a locale source. A user action can result in generation of an HTML POST request with query parameters that can be a basis of locale source. Even the HTTP protocol's headers can be yet another source of these locale parameters.

    The user locale is determined according to the list of LocaleSource class declarations in the GDK application configuration file. The GDK examines each LocaleSource class declaration, in the list using the declared order of the list. The first available LocaleSource is used for the user locale.

    The GDK provides the following pre-defined LocaleSource implementations:

    Note ApplicationDefault locale source is implicitly registered in the end of the locale source. If no other locale source is available, the ApplicationDefault locale source is used.

    Using the GDK configuration, the language of an application (User Interface) can be configured in many ways. The GDK configuration example below, illustrates configuration for a scenario where the language of an initial application page will be determined based on the language setting of the browser. Additionally, the user will be able to override this language by choosing from the available list of locales displayed in a Locale Selection drop-down. For example, if the browser language setting is Chinese, then pointing your browser to this application will display the User Interface in the Chinese language. Furthermore, the user can select Swiss (German) locale from the Locale Selection dropdown to change the application user interface to display German. The configuration below (from a gdkapp.xml) is used by the GDK to first try to use the Accept-Language HTTP header as the source of the locale, unless it is overridden by user input, which in the application's case is the selection of the locale from a Locale Selection dropdown. When the user picks the locale from the dropdown, the JSP posts a locale parameter value containing the selected locale. The GDK then sends a response, with the contents in the selected language. 

     <locale-determine-rule>
   <locale-source>
     oracle.i18n.servlet.localesource.UserInput
   </locale-source>
   <locale-source>
     oracle.i18n.servlet.localesource.HttpAcceptLanguage
   </locale-source>
 </locale-determine-rule>

    To create a custom locale source object, extend this class. The custom object for instance, may access the Oracle database to fetch and update the user locale preference, or it may access the LDAP server to get and set the language preference elements. Three methods must be implemented in the custom locale source:

    • public static LocaleSource getInstance(HttpServletRequest) - used to instantiate the object. It returns the object if it succeeds, otherwise null.
    • public boolean load() - used to load the locale and its attributes from the locale source.
    • public boolean store() - used to store the locale and its attributes into the locale source. If the locale source is read-only, this method should do nothing but return true.
    Implement the following method if the locale source can be cached:
    • public static boolean isAccessible(HttpServletRequest) - used to check if the locale source is accessible before using the cached object. It returns true if the locale source is accessible, otherwise false. If this method is not implemented, the GDK assumes that the locale source is always accessible.
    In the constructor, the following parameters must be specified:
    • cache flag - indicates whether the locale source can be cached. If the access cost to the locale source is not trivial, such as LDAP server, this flag should be true, otherwise false.
    • read-only flag - indicates whether the locale source is read-only. If the locale source cannot be updated, such as the Accept-Language item in the HTTP header, this flag is true, otherwise false.

    For example, the locale source accessing the LDAP server should be cached so that the GDK keeps the locale information while the user is valid. Once the user logs out, the locale information is no longer valid.

    Since:
    10.1.0.2
    See Also:
    Serialized Form

    • Constructor Detail

      • LocaleSource

        protected LocaleSource​(boolean isCached,
                       boolean isReadOnly)
        Constructs a LocaleSource object.
        Parameters:
        isCached - true if the locale source can be cached
        isReadOnly - true if the locale source is read-only

    • Method Detail

      • isCached

        public final boolean isCached()
        Checks if the LocaleSource object is cached.
        Returns:
        true if this object is cached; false otherwise.

      • isReadOnly

        public final boolean isReadOnly()
        Checks if the LocaleSource object is read-only.

        If this is true, creation and update operations on this object are omitted.

        Returns:
        true if this object is read-only; false otherwise.

      • store

        public abstract boolean store()
        Stores the locale and all attributes of the object in the actual LocaleSource class.

        This method must be implemented by the concrete classes.

        Returns:
        true if the storing operation is successful; false otherwise

      • load

        public abstract boolean load()
        Loads the locale and all attributes from the actual locale source into this object.

        This method must be implemented by the concrete classes.

        Returns:
        true if the loading operation is successful; false otherwise

      • setLocale

        public final void setLocale​(Locale locale)
        Registers the Locale object with this object.
        Parameters:
        locale - the Locale object

      • setLocale

        public final void setLocale​(Locale locale,
                            ApplicationContext appctx)
        Registers the locale object in this object.
        Parameters:
        locale - the Locale object
        appctx - the ApplicationContext object

      • setISOCurrency

        public final void setISOCurrency​(String currency)
        Registers the ISO currency to store in the actual LocaleSource class.
        Parameters:
        currency - the ISO currency ID defined in ISO 4217

      • setCharacterSet

        public final void setCharacterSet​(String charset)
        Registers the Oracle character set name to store in the actual LocaleSource class.
        Parameters:
        charset - the Oracle character set name

      • setLocaleSourceClass

        public final void setLocaleSourceClass​(Class loccls)
        Registers the locale source class object.
        Parameters:
        loccls - a Class object

      • setTimeZone

        public final void setTimeZone​(TimeZone tz)
        Registers the TimeZone ID to store in the actual LocaleSource class. For example: America/Los_Angeles
        Parameters:
        tz - a TimeZone object to register

      • setDateTimeFormat

        public final void setDateTimeFormat​(int dtstyle,
                                    OraDateFormat dtfmt)
        Registers the Oracle date time format object to store in the actual LocaleSource class.
        Parameters:
        dtstyle - the date format style defined in the OraDateFormat class
        dtfmt - an OraDateFormat object

      • setDateFormat

        public final void setDateFormat​(int style,
                                OraDateFormat dtfmt)
        Registers the Oracle date format object to store in the actual LocaleSource class.
        Parameters:
        style - the date format style defined in the OraDateFormat class
        dtfmt - an OraDateFormat object

      • setTimeFormat

        public final void setTimeFormat​(OraDateFormat tmfmt)
        Registers the Oracle time format object to store in the actual LocaleSource class.
        Parameters:
        tmfmt - an OraDateFormat object

      • setWritingDirection

        public final void setWritingDirection​(LocaleSource.WritingDirection wdir)
        Registers the writing direction to store in the actual LocaleSource class.
        Parameters:
        wdir - a writing direction of text on display

      • setCurrencyFormat

        public final void setCurrencyFormat​(OraNumberFormat nfmt)
        Registers the Oracle currency format object to store in the actual LocaleSource class.
        Parameters:
        nfmt - an OraNumberFormat object to register

      • setNumberFormat

        public final void setNumberFormat​(OraNumberFormat nfmt)
        Registers the Oracle number format object to store in the actual LocaleSource class.
        Parameters:
        nfmt - an OraNumberFormat object to register

      • setCollator

        public final void setCollator​(OraCollator ocol)
        Registers the Oracle collator to store in the actual LocaleSource class.
        Parameters:
        ocol - an OraCollator object to register

      • setAttribute

        protected final void setAttribute​(String key,
                                  Object object)
        Registers an attribute object in the locale source.

        Used in the concrete classes to set custom attributes.
        Note the attribute object must be Serializable.

        Parameters:
        key - a String key of object
        object - an object

      • getLocale

        public final Locale getLocale()
        Returns the Locale object in this object.
        Returns:
        Locale object

      • getISOCurrency

        public final String getISOCurrency()
        Returns the ISO 4217 currency ID in this object.
        Returns:
        the ISO 4217 currency ID

      • getCharacterSet

        public final String getCharacterSet()
        Returns the character set name in this object.
        Returns:
        the character set name

      • getLocaleSourceClass

        public final Class getLocaleSourceClass()
        Returns the locale source class.
        Returns:
        the locale source class

      • getTimeZone

        public final TimeZone getTimeZone()
        Returns the time zone in this object.
        Returns:
        a TimeZone object

      • getDateTimeFormat

        public final OraDateFormat getDateTimeFormat​(int style)
        Returns the Oracle date and time format of the specified style in this object.
        Parameters:
        style - the Date format style
        Returns:
        an OraDateFormat object

      • getDateFormat

        public final OraDateFormat getDateFormat​(int style)
        Returns the Oracle date format of the specified style in this object.
        Parameters:
        style - the Date format style
        Returns:
        an OraDateFormat object

      • getTimeFormat

        public final OraDateFormat getTimeFormat()
        Returns the Oracle time format in this object.
        Returns:
        the Oracle time format

      • getWritingDirection

        public final LocaleSource.WritingDirection getWritingDirection()
        Returns the writing direction in this object.
        Returns:
        a WritingDirection object

      • getCurrencyFormat

        public final OraNumberFormat getCurrencyFormat()
        Returns the Oracle currency format in this object.
        Returns:
        an OraNumberFormat object

      • getNumberFormat

        public final OraNumberFormat getNumberFormat()
        Returns the Oracle number format in this object.
        Returns:
        an OraNumberFormat object

      • getCollator

        public final OraCollator getCollator()
        Returns the Oracle collator object.
        Returns:
        an OraCollator object

      • getAttribute

        protected final Object getAttribute​(String key)
        Returns the attribute object.

        Used in the concrete classes to retrieve custom attributes. Note the attribute object must be Serializable.

        Parameters:
        key - a String key of object
        Returns:
        an Object associated with the key

      • equals

        public boolean equals​(Object o)
        Determines if a specific object is equal to this object.
        Overrides:
        equals in class Object
        Parameters:
        o - an Object to be compared
        Returns:
        boolean true if the objects are equal; false otherwise

      • hashCode

        public int hashCode()
        Returns the hash value of this object.
        Overrides:
        hashCode in class Object
        Returns:
        hash value