Design Patterns and Best Practices in Java

Implementation

The iterator pattern is based on two abstract classes or interfaces, which can be implemented by pairs of concrete classes. The class diagram is as follows:

The following classes are used in the iterator pattern:

• Aggregate: The abstract class that should be implemented by all the classes and can be traversed by an iterator. This corresponds to the java.util.Collection interface.
• Iterator: This is the iterator abstraction that defines the operations to traverse the aggregate object along with the one to return the object.
• ConcreteAggregate: Concrete aggregates can implement internally different structures, but expose the concrete ...