J2EE Design Patterns

Name

Lockable Object Pattern

Goal

Implement simple locking within a single JVM (Figure B-15).

Figure B-15. Lockable object

Participants

Business delegate

Provides access to business logic.

Lockable object

Provides a data object that can be locked for exclusive use by a business delegate.

Interactions

When a business delegate needs to modify an object, it calls the object’s lock( ) method. If a lock can be obtained, the business delegate updates the object and releases the lock.