Interface ResourceBundleProvider
- All Known Implementing Classes:
AbstractResourceBundleProvider
public interface ResourceBundleProvider
ResourceBundleProvider
is a service provider interface for resource bundles. It is used by ResourceBundle.getBundle
factory methods to locate and load the service providers that are deployed as modules via ServiceLoader
.
Developing resource bundle services
A service for a resource bundle of a givenbaseName
must have a fully-qualified class name of the form: <package of baseName> + ".spi." + <simple name of baseName> + "Provider"The service type is in a
spi
subpackage as it may be packaged in a module separate from the resource bundle providers. For example, the service for a resource bundle named com.example.app.MyResources
must be com.example.app.spi.MyResourcesProvider
: package com.example.app.spi; public interface MyResourcesProvider extends ResourceBundleProvider { }
Deploying resource bundle service providers
Resource bundles can be deployed in one or more service providers in modules. For example, a provider for a service named "com.example.app.spi.MyResourcesProvider
" has the following implementation class: import com.example.app.spi.MyResourcesProvider; class MyResourcesProviderImpl extends AbstractResourceBundleProvider implements MyResourcesProvider { public MyResourcesProviderImpl() { super("java.properties"); } // this provider maps the resource bundle to per-language package protected String toBundleName(String baseName, Locale locale) { return "p." + locale.getLanguage() + "." + baseName; } public ResourceBundle getBundle(String baseName, Locale locale) { // this module only provides bundles in French if (locale.equals(Locale.FRENCH)) { return super.getBundle(baseName, locale); } // otherwise return null return null; } }This example provides "
com.example.app.MyResources
" resource bundle of the French locale. Traditionally resource bundles of all locales are packaged in the same package as the resource bundle base name. When deploying resource bundles in more than one modules and two modules containing a package of the same name, split package, is not supported, resource bundles in each module can be packaged in a different package as shown in this example where this provider packages the resource bundles in per-language package, i.e. com.example.app.fr
for French locale.
A provider can provide more than one services, each of which is a service for a resource bundle of a different base name.
AbstractResourceBundleProvider
provides the basic implementation for ResourceBundleProvider
and a subclass can override the toBundleName
method to return a provider-specific location of the resource to be loaded, for example, per-language package. A provider can override ResourceBundleProvider.getBundle
method for example to only search the known supported locales or return resource bundles in other formats such as XML.
The module declaration of this provider module specifies the following directive:
provides com.example.app.spi.MyResourcesProvider with com.example.impl.MyResourcesProviderImpl;
Obtaining resource bundles from providers
The module declaration of the consumer module that calls one of theResourceBundle.getBundle
factory methods to obtain a resource bundle from service providers must specify the following directive: uses com.example.app.spi.MyResourcesProvider;
ResourceBundle.getBundle("com.example.app.MyResource", locale)
locates and loads the providers for com.example.app.spi.MyResourcesProvider
service and then invokes ResourceBundleProvider.getBundle("com.example.app.MyResource", locale)
to find the resource bundle of the given base name and locale. If the consumer module is a resource bundle service provider for com.example.app.spi.MyResourcesProvider
, ResourceBundle.getBundle
will locate resource bundles only from service providers. Otherwise, ResourceBundle.getBundle
may continue the search of the resource bundle in other modules and class path per the specification of the ResourceBundle.getBundle
method being called.- Since:
- 9
- See Also:
-
AbstractResourceBundleProvider
, Resource Bundles and Named Modules,ServiceLoader
Method Summary
Modifier and Type | Method | Description |
---|---|---|
ResourceBundle | getBundle(String baseName,
Locale locale) | Returns a |
Method Detail
getBundle
ResourceBundle getBundle(String baseName, Locale locale)
Returns a ResourceBundle
for the given bundle name and locale. This method returns null
if there is no ResourceBundle
found for the given parameters.
- Parameters:
-
baseName
- the base bundle name of the resource bundle, a fully qualified class name -
locale
- the locale for which the resource bundle should be loaded - Returns:
- the ResourceBundle created for the given parameters, or null if no
ResourceBundle
for the given parameters is found