By using Mediator pattern we can decouple the multiple objects that

interact with each other. With a Mediator object we can create

many-to-many relationships in multiple objects.

In JDK there are many places where Mediator design pattern is

used. Some of these are as follows:

java.util.Timer: schedule() methods in Timer class act as

Mediator between the clients and the TimerTask to be

scheduled.

java.util.concurrent.Executor.execute(): The execute()

method in an Executor class acts as a Mediator to execute

the different tasks.

java.util.concurrent.ExecutorService

java.lang.reflect.Method.invoke(): In Method class of

reflection package, invoke() method acts as a Mediator.

java.util.concurrent.ScheduledExecutorService: Here also

schedule() method and its variants are Mediator pattern

implementations.

https://www.digitalocean.com/community/tutorials/mediator-design-pattern-java