Java Design Patterns Reference List and Examples

Gang of Four (GoF) Creational Patterns

Abstract Factory : Sets of methods to make various objects.

Builder : Make and return one object various ways.
Factory Method Methods to make and return components of one object various ways.
Prototype Make new objects by cloning the objects which you set as prototypes.
Singleton A class distributes the only instance of itself.

GoF Structural Patterns
Adapter A class extends another class, takes in an object, and makes the taken object behave like the extended class.
Bridge An abstraction and implementation are in different class hierarchies.
Composite Assemble groups of objects with the same signature.
Decorator One class takes in another class, both of which extend the same abstract class, and adds functionality.
Facade One class has a method that performs a complex process calling several other classes.
Flyweight The reusable and variable parts of a class are broken into two classes to save resources.
Proxy One class controls the creation of and access to objects in another class.
GoF Behavorial Patterns
Chain Of Responsibility A method called in one class can move up a hierarchy to find an object that can properly execute the method.
Command An object encapsulates everything needed to execute a method in another object.
Interpreter Define a macro language and syntax, parsing input into objects which perform the correct opertaions.
Iterator One object can traverse the elements of another object.
Mediator An object distributes communication between two or more objects.
Memento One object stores another objects state.
Observer An object notifies other object(s) if it changes.
State An object appears to change its` class when the class it passes calls through to switches itself for a related class.
Strategy An object controls which of a family of methods is called. Each method is in its` own class that extends a common base class.
Template An abstract class defines various methods, and has one non-overridden method which calls the various methods.
Visitor One or more related classes have the same method, which calls a method specific for themselves in another class.