Skip to main content

J2EE Design Patterns



Creational Design Pattern

Creational: Singleton



when to use :
Used in Logging, Cache, Session, Drivers 


Creational: Factory 
When to use :


Implementation :

Factory chooses the objects, DAO, Abstract DAO factory 



Creational:builder  
Defines essiential parameter in constructor & optional in setters & add build method .Call build method at the end.







Creational: Prototype






  

Creational:AbstractFactory 
Structural 

improves  the structure of code
Structural: prototype 

Clone method 

Structural: proxy 

Structural: Facade 





Structural: Composite Design Pattern

 
Structural: Flyweight Design Pattern



Structural: Adapter



 

Structural: Bridge 



Behavioural

Behavioural:template 

Subclass defines behvaiour , order of exectution can be defined in superclass  

Behavioural:Observer 

Subclass defines behvaiour , order of exectution can be defined in superclass 


Concurrency Patterns


Thread pool Pattern is special case of Object pool design pattern 







Labels:

Comments

Post a Comment

Popular posts from this blog

Microservices Design patterns

What are microservices? Microservices - also known as the microservice architecture - is an architectural style that structures an application as a collection of services that are Highly maintainable and testable Loosely coupled Independently deployable Organized around business capabilities Owned by a small team The microservice architecture enables the rapid, frequent and reliable delivery of large, complex applications. It also enables an organization to evolve its technology stack. You are developing a server-side enterprise application. It must support a variety of different clients including desktop browsers, mobile browsers and native mobile applications. The application might also expose an API for 3rd parties to consume. It might also integrate with other applications via either web services or a message broker. The application handles requests (HTTP requests and messages) by executing business logic; accessing a database; exchanging messages with other systems; and returni...
Post a Comment
Read more

GraphQL

What is GraphQL  API Standard invented & open-sourced by Facebook Alternative to  REST API  enables declarative data fetching  exposes single endpoint & responds to queries How it works?  Why Graphql? Improvises performance by reducing the data that is to be transferred over the internet Variety of different frontend frameworks and platforms on client-side Fast development speed & expectation for rapid feature development Why Graphql is better than REST? Flexibility & efficient  No more over /under fetching of data Over fetching : Under fetching: Insightful analytics  Schema serves as contract between client and server CORE CONCEPTS : SDL :SCHEMA DEFINITION LANGUAGE Writing Data with mutations 3 kinds of mutations creating new data updating existing data deleting existing data
Post a Comment
Read more

Jackson

<dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId> jackson-core </artifactId> <version>2.9.6</version> </dependency> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId> jackson-annotations </artifactId> <version>2.9.6</version> </dependency> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId> jackson-databind </artifactId> <version>2.9.6</version> </dependency> CBOR encoded data with Jackson <dependency> <groupId>com.fasterxml.jackson.dataformat</groupId> <artifactId>jackson-dataformat-cbor</artifactId> <version>2.9.6</version> </dependency> In order to read and write MessagePack encoded data <dependency> <groupId>org.msgpack</groupId> <artifactId>jackson-dataformat-msgp...
Post a Comment
Read more