1.2.3. Object Adapter vs Proxy
From the book:
In the proxy pattern, the
RealSubject implements the
Subject interface. If we take away the inheritance relationship, is this still a proxy or does it become an adapter? Similarly, if in an adapter the
Adaptee happens to implement
Target, does the pattern become a proxy?
It depends on the intent. For example, with session beans in EJB, the implementation bean does not inherit directly from the remote interface, because the methods throw incompatible exceptions. The remote interface would throw
RemoteException, whereas the implementation bean would throw business exceptions.
An object adapter has a similar structure to the proxy. In both cases, the client uses the top-level interfaces
Subject. We have implementations of this interface in