Skip to main content

Object Oriented Design Patterns


What is a Design Pattern?
In software engineering design patterns refers to a solution template which can be regarded as best practice for problems which occurs often.  A design pattern is simply a solution template  that should be implemented according to problem at hand.
Object Oriented design patterns aims to solve common problems  which are encountered during object oriented design. Object oriented design patterns advises the involved classes and relationships among those classes but leaves actuall class definitions to implementor.

For more detail: Software design pattern

What are types of Design Patterns?
There are three types of design patterns:

1.       Creational Design Patterns
Refers to desing patterns that are used to create objects. Most well known creational patterns are listed below:
-       Singleton
-       Factory
-       Factory Method
-       Abstract Factory
-       Builder
-       Prototype
-       Object Pool


2.       Behavioral Design Patterns
Refers to desing patterns which involves advises on behavior of desing. Well known patterns are listed below:
-       Memento
-       Mediator
-       Observer
-       Null Object
-       Visitor
-       Interpreter
-       Iterator
-       Strategy
-       Command
-       Template Method
-       Chain of Responsibility

3.       Structural Design Patterns
Refers to desing patterns which involves advises on structure of desing. Well known patterns are listed below:
-          Adapter
-          Bridge
-          Composite
-          Decorator
-          Flyweight
-          Proxy

Labels:

Comments

Post a Comment

Popular posts from this blog

Obfuscating Spring Boot Projects Using Maven Proguard Plugin

Introduction Obfuscation is the act of reorganizing bytecode such that it becomes hard to decompile. Many developers rely on obfuscation to save their sensitive code from undesired eyes. Publishing jars without obfuscation may hinder competitiveness because rivals may take advantage of easily decompilable nature of java binaries. Objective Spring Boot applications make use of public interfaces, annotations which makes applications harder to obfuscate. Additionally, maven Spring Boot plugin creates a fat jar which contains all dependent jars. It is not viable to obfuscate the whole fat jar. Thus obfuscating Spring Boot applications is different than obfuscating regular java applications and requires a suitable strategy. Audience Those who use Spring Boot and Maven and wish to obfuscate their application using Proguard are the target audience for this article. Sample Application As the sample application, I will use elastic search synch application from my G...
4 comments
Read more

Hadoop Installation Document - Standalone Mode

This document shows my experience on following apache document titled “Hadoop:Setting up a Single Node Cluster”[1] which is for Hadoop version 3.0.0-Alpha2 [2]. A. Prepare the guest environment Install VirtualBox. Create a virtual 64 bit Linux machine. Name it “ubuntul_hadoop_master”. Give it 500MB memory. Create a VMDK disc which is dynamically allocated up to 30GB. In network settings in first tab you should see Adapter 1 enabled and attached to “NAT”. In second table enable adapter 2 and attach to “Host Only Adaptor”. First adapter is required for internet connection. Second one is required for letting outside connect to a guest service. In storage settings, attach a Linux iso file to IDE channel. Use any distribution you like. Because of small installation size, I choose minimal Ubuntu iso [1]. In package selection menu, I only left standard packages selected.  Login to system.  Setup JDK. $ sudo apt-get install openjdk-8-jdk Install ssh and pdsh, if...
3 comments
Read more

Behavioral Patterns : Chain of Responsibilities

Properties: -            Lets a request to be passed sequentially to a set of handlers. -            Each handler decides wheter to handle the request or pass it to next handler. Implementation: -            Handler  interface declares operations to handle requests. -            ConcreteHandler  decides wheter to handle the request or pass it to next handler. Java Standard Library Implementations: -            javax.servlet.Filter#doFilter(ServletRequest request,ServletResponse response,FilterChain chain) -            java.util.logging.Logger#log(Level,String) Example Usage: public   class  Logger  {      public ...
Post a Comment
Read more