Design Patterns in Java

This repo contains a series of Design Patterns examples written in Java. They are taken from Bryan Hansen's design patterns courses on PluralSight:

• https://app.pluralsight.com/library/courses/design-patterns-java-behavioral/table-of-contents
• https://app.pluralsight.com/library/courses/design-patterns-java-structural/table-of-contents
• https://app.pluralsight.com/library/courses/design-patterns-java-creational/table-of-contents

Creational

• Builder
  • Handles the construction of objects that may contain a lot of parameters and want to make the object immutable once we’re done constructing it.
• Factory
  • Creational pattern that doesn’t expose instantiation logic -it does this by deferring instantiation logic to a subclass. The client only knows about a common interface that the factory exposes.
• Prototype
  • Used when the type of object to create is determined by a prototypical instance which is cloned to produce a new instance. Often this is used to get a unique instance of the same object.
• Singleton
  • Guarantees one instance of a class will be created; and the control of that resource -can be lazy loaded.

Structural

• Adapter
  • Concerned with connecting new code to legacy code without having to change the working contract that was produced from the legacy code originally.
• Bridge
  • Similar to adapter, but working with new code instead of legacy code.
• Composite
  • Hierarchical type pattern that deals with tree structures of information.
• Decorator
  • Hierarchical type pattern that builds functionality at each level while using composition from similar data types.
• Flyweight
  • Minimizes memory use by sharing data with similarly typed objects.
• Proxy
  • Acts as an interface to something else.

Behavioral

• Interpreter
  • Provide navigation without exposing the structure of an object.
• Mediator
  • Used to define how objects interact with one another without having them refer to each other explicitly.
• Memento
  • Used to externalize an object’s state, usually to provide rollback functionality.
• Observer
  • A decoupling pattern when we have a subject that needs to be observed by one or more observers.
• Strategy
  • Used when you want to enable the strategy (or algorithm) to be selected at runtime.
• Template
  • Define an algorithm that allows subclasses to redefine parts of the algorithm without changing its structure.
• Visitor
  • Separates an algorithm from an object structure.