Mediator

• Defines simplified communication between classes
• Define an object that encapsulates how a set of objects interact
• Promote loose coupling by keeping objects from referring to each other explicitly
• Vary their interaction independently

Mediator

• Defines an interface for communicating with Colleague objects

ConcreteMediator

• Implements cooperative behavior by coordinating Colleague objects
• Knows and maintains its colleagues

Colleague classes

• Each Colleague class knows its Mediator object
• Each colleague communicates with its mediator whenever it would have otherwise communicated with another colleague