This feature enables the plug-in of locale-dependent data and services. In this way, third parties are able to provide implementations of most locale-sensitive classes in the
java.text
andjava.util
packages.The implementation of SPIs (Service Provider Interface) is based on abstract classes and Java interfaces that are implemented by the service provider. At runtime the Java class loading mechanism is used to dynamically locate and load classes that implement the SPI.
You can use the locale-sensitive services SPI to provide the following locale sensitive implementations:
The corresponding SPIs are contained both in
BreakIterator
objectsCollator
objects- Language code, Country code, and Variant name for the
Locale
class- Time Zone names
- Currency symbols
DateFormat
objectsDateFormatSymbol
objectsNumberFormat
objectsDecimalFormatSymbols
objectsjava.text.spi
and injava.util.spi
packages:
java.util.spi
java.text.spi
CurrencyNameProvider
LocaleServiceProvider
TimeZoneNameProvider
BreakIteratorProvider
CollatorProvider
DateFormatProvider
DateFormatSymbolsProvider
DecimalFormatSymbolsProvider
NumberFormatProvider
For example, if you would like to provide a
NumberFormat
object for a new locale, you have to implement thejava.text.spi.NumberFormatProvider
class. You need to extend this class and implement its methods:
getCurrencyInstance(Locale locale)
getIntegerInstance(Locale locale)
getNumberInstance(Locale locale)
getPercentInstance(Locale locale)
Locale loc = new Locale("da", "DK"); NumberFormat nf = NumberFormatProvider.getNumberInstance(loc);These methods first check whether the Java runtime environment supports the requested locale; if so, they use that support. Otherwise, the methods call the
getAvailableLocales()
methods of installed providers for the appropriate interface to find a provider that supports the requested locale.