# design-patterns **Repository Path**: witless/design-patterns ## Basic Information - **Project Name**: design-patterns - **Description**: No description available - **Primary Language**: Java - **License**: Not specified - **Default Branch**: master - **Homepage**: None - **GVP Project**: No ## Statistics - **Stars**: 0 - **Forks**: 0 - **Created**: 2017-04-06 - **Last Updated**: 2020-12-19 ## Categories & Tags **Categories**: Uncategorized **Tags**: None ## README # Software design pattern ### [Creational patterns](https://en.wikipedia.org/wiki/Creational_pattern) | Name | Description | | ---------------------------------------- | ---------------------------------------- | | [Abstract factory](https://en.wikipedia.org/wiki/Abstract_factory_pattern) | Provide an interface for creating *families* of related or dependent objects without specifying their concrete classes. | | [Builder](https://en.wikipedia.org/wiki/Builder_pattern) | Separate the construction of a complex object from its representation, allowing the same construction process to create various representations. | | [Factory method](https://en.wikipedia.org/wiki/Factory_method_pattern) | Define an interface for creating a *single* object, but let subclasses decide which class to instantiate. Factory Method lets a class defer instantiation to subclasses ([dependency injection](https://en.wikipedia.org/wiki/Dependency_injection)[[19\]](https://en.wikipedia.org/wiki/Software_design_pattern#cite_note-19)). | | [Lazy initialization](https://en.wikipedia.org/wiki/Lazy_initialization) | Tactic of delaying the creation of an object, the calculation of a value, or some other expensive process until the first time it is needed. This pattern appears in the GoF catalog as "virtual proxy", an implementation strategy for the [Proxy](https://en.wikipedia.org/wiki/Proxy_pattern) pattern. | | [Prototype](https://en.wikipedia.org/wiki/Prototype_pattern) | Specify the kinds of objects to create using a prototypical instance, and create new objects from the 'skeleton' of an existing object, thus boosting performance and keeping memory footprints to a minimum. | | [Singleton](https://en.wikipedia.org/wiki/Singleton_pattern) | Ensure a class has only one instance, and provide a global point of access to it. | ### [Structural patterns](https://en.wikipedia.org/wiki/Structural_pattern) | Name | Description | | ---------------------------------------- | ---------------------------------------- | | [Adapter](https://en.wikipedia.org/wiki/Adapter_pattern) | Convert the interface of a class into another interface clients expect. An adapter lets classes work together that could not otherwise because of incompatible interfaces. The enterprise integration pattern equivalent is the translator. | | [Bridge](https://en.wikipedia.org/wiki/Bridge_pattern) | Decouple an abstraction from its implementation allowing the two to vary independently. | | ~~[Composite](https://en.wikipedia.org/wiki/Composite_pattern)~~ | Compose objects into tree structures to represent part-whole hierarchies. Composite lets clients treat individual objects and compositions of objects uniformly. | | [Decorator](https://en.wikipedia.org/wiki/Decorator_pattern) | Attach additional responsibilities to an object dynamically keeping the same interface. Decorators provide a flexible alternative to subclassing for extending functionality. | | [Facade](https://en.wikipedia.org/wiki/Facade_pattern) | Provide a unified interface to a set of interfaces in a subsystem. Facade defines a higher-level interface that makes the subsystem easier to use. | | ~~[Flyweight](https://en.wikipedia.org/wiki/Flyweight_pattern)~~ | Use sharing to support large numbers of similar objects efficiently. | | [Proxy](https://en.wikipedia.org/wiki/Proxy_pattern) | Provide a surrogate or placeholder for another object to control access to it. | ### [Behavioral patterns](https://en.wikipedia.org/wiki/Behavioral_pattern) | Name | Description | | ---------------------------------------- | ---------------------------------------- | | [Chain of responsibility](https://en.wikipedia.org/wiki/Chain_of_responsibility_pattern) | Avoid coupling the sender of a request to its receiver by giving more than one object a chance to handle the request. Chain the receiving objects and pass the request along the chain until an object handles it. | | [Command](https://en.wikipedia.org/wiki/Command_pattern) | Encapsulate a request as an object, thereby allowing for the parameterization of clients with different requests, and the queuing or logging of requests. It also allows for the support of undoable operations. | | ~~[Interpreter](https://en.wikipedia.org/wiki/Interpreter_pattern)~~ | Given a language, define a representation for its grammar along with an interpreter that uses the representation to interpret sentences in the language. | | [Iterator](https://en.wikipedia.org/wiki/Iterator_pattern) | Provide a way to access the elements of an [aggregate](https://en.wikipedia.org/wiki/Aggregate_pattern) object sequentially without exposing its underlying representation. | | [Mediator](https://en.wikipedia.org/wiki/Mediator_pattern) | Define an object that encapsulates how a set of objects interact. Mediator promotes [loose coupling](https://en.wikipedia.org/wiki/Loose_coupling) by keeping objects from referring to each other explicitly, and it allows their interaction to vary independently. | | ~~[Memento](https://en.wikipedia.org/wiki/Memento_pattern)~~ | Without violating encapsulation, capture and externalize an object's internal state allowing the object to be restored to this state later. | | [Observer](https://en.wikipedia.org/wiki/Observer_pattern) or [Publish/subscribe](https://en.wikipedia.org/wiki/Publish/subscribe) | Define a one-to-many dependency between objects where a state change in one object results in all its dependents being notified and updated automatically. | | [State](https://en.wikipedia.org/wiki/State_pattern) | Allow an object to alter its behavior when its internal state changes. The object will appear to change its class. | | [Strategy](https://en.wikipedia.org/wiki/Strategy_pattern) | Define a family of algorithms, encapsulate each one, and make them interchangeable. Strategy lets the algorithm vary independently from clients that use it. | | [Template method](https://en.wikipedia.org/wiki/Template_method_pattern) | Define the skeleton of an algorithm in an operation, deferring some steps to subclasses. Template method lets subclasses redefine certain steps of an algorithm without changing the algorithm's structure. | | [Visitor](https://en.wikipedia.org/wiki/Visitor_pattern) | Represent an operation to be performed on the elements of an object structure. Visitor lets a new operation be defined without changing the classes of the elements on which it operates. |