32 lines
1.4 KiB
Markdown
32 lines
1.4 KiB
Markdown
# Mediator Design Pattern — Java Example
|
|
|
|
**Pattern:** Behavioral → Mediator
|
|
**Article:** https://ankurm.com/mediator-design-pattern-java/
|
|
|
|
## What this example shows
|
|
|
|
A chat room where users never talk to each other directly. `ChatMediator` declares the hub contract (`sendMessage()`/`addUser()`). `User` is a colleague — it knows only the mediator, never other users. `ChatRoom` is the concrete mediator: it holds the list of users and routes every message to everyone except the sender. `Main` adds three users and has each one broadcast a message, then prints the O(N) vs O(N²) connection-count comparison.
|
|
|
|
## How to run
|
|
|
|
```bash
|
|
javac mediator/*.java -d out/mediator
|
|
java -cp out/mediator mediator.Main
|
|
```
|
|
|
|
Requires Java 25.
|
|
|
|
## Post Section ↔ File Mapping
|
|
|
|
| Post Section | File(s) |
|
|
|---|---|
|
|
| Implementation: Chat Room — the Mediator interface | `ChatMediator.java` |
|
|
| Implementation: Chat Room — the Colleague | `User.java` |
|
|
| Implementation: Chat Room — the Concrete Mediator | `ChatRoom.java` |
|
|
| Implementation: Chat Room — wiring it together | `Main.java` |
|
|
|
|
Note: the "Mediator in Practice: MVC and Spring Events" snippet (`ApplicationEventPublisher`/`@EventListener` example) is illustrative only — it is not part of this repository's runnable example.
|
|
|
|
Article: https://ankurm.com/mediator-design-pattern-java/
|
|
All patterns: https://ankurm.com/design-patterns-java/
|