Mediator Pattern

Mediator is about collaboration control. It becomes useful when components are not individually too complex, but the network of interactions between them is.

In Java systems, this often shows up in:

• UI coordination
• workflow orchestration
• multi-component validation or event routing
• subsystems where every component starts knowing too much about every other component

Mediator helps by centralizing interaction rules. It becomes harmful when it centralizes everything and turns into a god object.

In this section

• Implementing Mediator in Java
  Implement Mediator in Java by moving coordination rules into one explicit collaborator instead of spreading them across peer objects.
• Reducing Tight Coupling with the Mediator Pattern
  Use Mediator in Java to reduce peer-to-peer awareness without hiding the collaboration rules that still need to be designed explicitly.
• Mediator vs. Observer Pattern
  Compare Mediator and Observer in Java so centralized coordination and event notification are not treated as the same design move.
• Mediator Pattern Use Cases and Examples in Java
  See where Mediator genuinely helps in Java systems, especially in UI coordination, workflow hubs, and multi-component interaction rules.