From Java documentation:
A service is a well-known set of interfaces and (usually abstract) classes. A service provider is a specific implementation of a service. The classes in a provider typically implement the interfaces and subclass the classes defined in the service itself. Service providers can be installed in an implementation of the Java platform in the form of extensions, that is, jar files placed into any of the usual extension directories. Providers can also be made available by adding them to the application's class path or by some other platform-specific means.
- "Introduction to the Service Provider Interfaces". Oracle Java Documentation.
Services are units of sound-handling functionality that are automatically available when an application program makes use of an implementation of the Java Sound API
- Thribhuvan Thakur (November 18, 2009). "Service Provider Interface: Creating Extensible Java Applications". Developer.com.
A service provider interface (SPI) is the set of public interfaces and abstract classes that a service defines. A SPI may be represented by a single interface (type) or abstract class or a set of interfaces or abstract classes that define the service contract.
- Seacord, C. Robert & Wrage, Lutz (July 2002). "Replaceable Components and the Service Provider Interface". Software Engineering Institute (CMU).
- Replaceable Components and the Service Provider Interface (.pdf at The Software Engineering Institute CMU)
- Official Java API documentation: java.util.ServiceLoader class and java.util.spi package