From ServiceLoader javadoc: A service is a well-known set of interfaces and 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.
Since JDK 6, a simple service-provider loading facility is implemented. As is suggested it is simple, you cannot understand that implementation as a complex system for implementing plugins for your application, but can help you in many situations where you want implementations of a service could be discovered by other module automatically.
What I really like about using JDK Services is that your services do not have any dependency to any class. Moreover for registering a new implementation of a service, you just have to put jar file into classpath and nothing more.
Now I will explain the service we are going to implement, and then I will show you how to code it.
We want to implement a system that depending on kind of structured input (comma-separated value, tab-separated value, ...) returns a String of each value; so for example you can receive input a,b,c,dor 1<tab>2<tab>3<tab>4 and the system should return an array with [a, b, c, d] or [1, 2, 3, 4].
So our system will have three Java projects.