upidiff.i18n
Class Catalog

java.lang.Object
  |
  +--upidiff.i18n.Catalog

public final class Catalog

extends Object

This class represents a language catalog.

Author:

bmeurer

Nested Class Summary

private class

Catalog.CatalogFilenameFilter Filename filter for catalog files.

Field Summary

private Language[]	availableLanguages List of available languages.
private Language	currentLanguage Currently selected language.
private static Catalog	instance Global Catalog instance.
private List	listeners List of CatalogListeners.
private ResourceBundle	resource The language catalog backend.

Constructor Summary

private

Catalog() Constructs a new Catalog object.

Method Summary

void	addCatalogListener(CatalogListener listener) Registers a CatalogListener.
Language[]	getAvailableLanguages() Queries the available languages.
Language	getCurrentLanguage() Returns the currently selected language.
static Catalog	getInstance() Returns a reference to the global Catalog instance.
String	getString(String identifier) Queries the catalog string for the given identifer.
boolean	hasString(String identifier) Checks if the given identifer is present in the catalog.
private String[]	lookupCatalogFiles(String resourcePath) Looks up the install catalog files.
void	removeCatalogListener(CatalogListener listener) Unregisters a CatalogListener.
void	setCurrentLanguage(Language language) Sets the language to be used by the Catalog.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

availableLanguages

private Language[] availableLanguages

List of available languages. An array of available languages found on the system. A language is available if both a language catalog file is found and the locale for that language is known by the Java runtime environment.

See Also:

getAvailableLanguages()

currentLanguage

private Language currentLanguage

Currently selected language.

See Also:

getCurrentLanguage()

listeners

private List listeners

List of CatalogListeners.

See Also:

addCatalogListener(upidiff.i18n.CatalogListener), removeCatalogListener(upidiff.i18n.CatalogListener)

resource

private ResourceBundle resource

The language catalog backend. The language catalog files itself are loaded through the ResourceBundle class.

See Also:

ResourceBundle

instance

private static Catalog instance

Global Catalog instance.

See Also:

getInstance()

Constructor Detail

Catalog

private Catalog()
         throws NoLanguagesFound

Constructs a new Catalog object. This constructor is private because only one instance of Catalog is allowed per process. It would not make much sense to have several catalogs in one process. Use getInstance() to obtain a reference to the global Catalog instance.

Throws:

NoLanguagesFound - This exception is thrown if no language catalogs can be found, neither in the system nor in the Jar archive.

See Also:

getInstance()

Method Detail

lookupCatalogFiles

private String[] lookupCatalogFiles(String resourcePath)

Looks up the install catalog files.

Parameters:

resourcePath - Resource path to the directory that contains the catalog files.

Returns:

An array of catalog filenames.

getInstance

public static Catalog getInstance()
                           throws NoLanguagesFound

Returns a reference to the global Catalog instance. This returns a reference to the global Catalog instance. If no global instance exists yet, a new instance is created.

Returns:

The global Catalog instance.

Throws:

NoLanguagesFound - This exception is thrown if no language catalogs can be found, neither in the system nor in the Jar archive.

See Also:

instance

getAvailableLanguages

public Language[] getAvailableLanguages()

Queries the available languages. Returns an array of available languages found on the system. A language is available if both a language catalog file is found and the locale for that language is known by the Java runtime environment.

Returns:

The available languages.

getCurrentLanguage

public Language getCurrentLanguage()

Returns the currently selected language.

Returns:

The currently selected language.

setCurrentLanguage

public void setCurrentLanguage(Language language)
                        throws InvalidLanguage

Sets the language to be used by the Catalog. If the language was changed successfully, all CatalogListeners are notified that the current language was changed.

Parameters:

language - The new language to set.

Throws:

InvalidLanguage - This exception is thrown if the supplied Language was not valid or if the language catalog file could not be loaded due to some system error (e.g. the user could have deleted the language catalog file). In this case the current language is not changed.

getString

public String getString(String identifier)

Queries the catalog string for the given identifer. If there was no catalog string found for the given identifier, the identifier itself is returned.

Parameters:

identifier - Unique identifier for a catalog string.

Returns:

The catalog string for the given identifier.

hasString

public boolean hasString(String identifier)

Checks if the given identifer is present in the catalog.

Parameters:

identifier - Unique identifer for a catalog string.

Returns:

true if the catalog string is present, else false.

addCatalogListener

public void addCatalogListener(CatalogListener listener)

Registers a CatalogListener. If the current language is changed due to a call to setCurrentLanguage() all registered CatalogListeners will be notifed.

Parameters:

listener - New CatalogListener to register.

See Also:

removeCatalogListener(upidiff.i18n.CatalogListener)

removeCatalogListener

public void removeCatalogListener(CatalogListener listener)

Unregisters a CatalogListener.

Parameters:

listener - CatalogListener to unregister.

See Also:

addCatalogListener(upidiff.i18n.CatalogListener)