js.util

Interface I18nPool<T>

Type Parameters:

T - type of objects stored by this cache.

All Known Implementing Classes:

I18nPoolFactory.LocalePool, I18nPoolFactory.SimplePool

public interface I18nPool<T>

Locale sensitive cache for named objects. An object into I18N pool is identified by an application level unique name and by locale settings. Both single and multiple locale implementations should be supported. Locale parameter is used only for implementations with multiple locale support; implementation should throw illegal argument exception if locale argument is missing. For single locale implementations locale argument is silently ignored.

Used locale should be based only on language and optional country, encoded with ISO 639 alpha-2, respective ISO 3166 alpha-2. Implementation should throw illegal argument exception if provided locale has script, variant or extension. Also, for string representation, implementations should use Locale.toLanguageTag() that guarantee usage of newly language codes. This is because, accordingly Java Locale API, language encoded ISO 639 alpha-2 is not a stable standard and has some codes changed.

To facilitate loading I18N cache from files system there is companion I18nRepository class. In code snippet below, iterate files from repository and update pool. Note that I18N file has locale detected by repository iterator while scanning the files system. For single locale repository detected locale is null but is ignored anyway by I18N pool, that is created also a single locale instance.

 // create single or multiple locale I18N pool accordingly repository support
 I18nPool pool = repository.getPoolInstance();
 
 for (I18nFile i18nFile : repository) {
        // create object instance and initialize it from file content
        File file = i18nFile.getFile();
        Template template = new Template(file);
 
        // store created object instance on cache, bound to file name and detected locale
        pool.put(file.getName(), template, i18nFile.getLocale());
 }
 

Version:

final

Author:

Iulian Rotaru

Method Summary

Modifier and Type	Method and Description
T	get(String name, Locale... locale) Get instance identified by name and optional locale settings.
boolean	has(String name, Locale... locale) Test if cache has an instance identified by given name and optional locale settings.
boolean	put(String name, T t, Locale... locale) Store an instance on this cache bound to given name and optional locale settings.

Method Detail

put

boolean put(String name,
            T t,
            Locale... locale)

Store an instance on this cache bound to given name and optional locale settings. To later retrieve stored instance one should know both instance name and locale settings. For implementations without multiple locale support, optional locale argument is silently ignored and not even tested for validity.

Parameters:

name - unique name with application scope,

t - object instance to store on cache,

locale - optional locale settings, mandatory for implementations with multiple locale support.

Returns:

true if object instance were already present.

Throws:

IllegalArgumentException - if name argument is null or empty or locale argument is missing, null or has variant, script or extension, on an implementation with multiple locale support.

get

T get(String name,
      Locale... locale)

Get instance identified by name and optional locale settings. Returns null if no instance found with specified criteria. For implementations without multiple locale support, optional locale argument is silently ignored and not even tested for validity.

Parameters:

name - unique name with application scope,

locale - optional locale settings, mandatory for implementations with multiple locale support.

Returns:

named instance or null.

Throws:

IllegalArgumentException - if name argument is null or empty or locale argument is missing, null or has variant, script or extension, on an implementation with multiple locale support.

has

boolean has(String name,
            Locale... locale)

Test if cache has an instance identified by given name and optional locale settings. For implementations without multiple locale support, optional locale argument is silently ignored and not even tested for validity.

Parameters:

name - unique name with application scope,

locale - optional locale settings, mandatory for implementations with multiple locale support.

Returns:

true if there is an instance identified by given criteria.

Throws:

IllegalArgumentException - if name argument is null or empty or locale argument is missing, null or has variant, script or extension, on an implementation with multiple locale support.