Chapter 1. Session Facade Pattern

Enterprise Java Development@TOPIC@

Chapter 1. Session Facade Pattern

1.1. Context
1.2. Problem
1.3. Forces
1.4. Solution
1.5. Consequences

1.1. Context

Multi-tiered application
Non-trivial business logic and data

1.2. Problem

Potential tight coupling between clients and complex business objects
Too many method invocations between clients and business objects
Business methods exposed for misuse by clients

Figure 1.1. Problem

Problem

1.3. Forces

Hide complex interactions behind a simple client interface
Reduce the number of business objects exposed to the client across the network
Hide implementation, interactions, and dependencies of business components

1.4. Solution

Use a business logic class to encapsulate the interactions required with the business objects

Figure 1.2. Solution

Solution

Figure 1.3. Participants

Participants

1.5. Consequences

Simplifies complex systems
May appear to be a no value pass-thru in simple systems
- Should involve more than one business object per facade
- Should have more than one facade per system
Decouples the business objects from being aware of one another
Improves perceived network performance for remote interfaces
Centralizes security and transactions in some cases