Facade vs. Adapter Pattern

Facade and Adapter both sit at boundaries, but they solve different problems.

Adapter

Adapter says:

• one dependency exposes the wrong interface
• translate that interface into the contract the client already wants

The focus is mismatch.

Facade

Facade says:

• the subsystem may be internally fine
• the client should not need to deal with all of it directly
• provide a simpler entry point for common tasks

The focus is simplification.

Practical Java Shortcut

Ask:

• “Am I translating an awkward API?” -> Adapter
• “Am I simplifying a busy subsystem boundary?” -> Facade

One can wrap the other, but they are not interchangeable.