Skip to main content

Abstract Factory DesignPattern-1

Abstract Factory Design Pattern

  • In software development, a factory is the location in the code at which objects are constructed. 
  • The intent in employing the pattern is to insulate the creation of objects from their usage. This allows for new derived types to be introduced with no change to the code that uses the base class.
  • The essence of the Abstract Factory method Pattern is to "Provide an interface for creating families of related or dependent objects without specifying their concrete classes".
  • For Example:
    • Address Factory has no of factories like:
      • US Address Factory which implements the Address Interface.
      • French Address Factory which implements the Address interface.
      • Can have many more country specific factories….
  • When we create the French Address using the method implemented in the French Address Factory class it returns the Object reference to the Abstract class of Address.
  • The Abstract Address class holds the abstract method named get Country() which is implemented separately by each implementing class

Popular posts from this blog

Primitive Obsession with Example

Primitive Obsession is the name of a code smell that occurs when we use primitive data types to represent domain ideas. For example, we use a string to represent a message or an integer to represent an amount of money. For Example: Code with Primitive Obsession // primitiveObsession.java public class primitiveObsession { public static void main ( String args []) { Integer [] cityPopulations = { 13000000 , // London 21903623 , // New York 12570000 , // Tokyo 1932763 , // Stockholm 1605602 , // Barcelona 4119190 // Sydney }; for ( Integer cityPopulation : cityPopulations ) { System . out . println ( cityPopulation ); } } } public class City { private final String name ; private final int population ; private final Continent continent ; public String getName () { return name ; } public int getPopulation () { return population ; } public Continent ge

Singleton Pattern

Lazy Initialization :- The instantiation of an object can be delayed until it is actually needed. Usage: This especially beneficial when the constructor is doing a costly job like, accessing a remote database. Example: This code demonstrates how the Singleton pattern can be used to create a counter to provide unique sequential numbers, such as might be required for use as primary keys in a Database:   Sequence.java   public class Sequence { private static Sequence instance; private static int counter; private Sequence() { counter = 0; // May be necessary to obtain // starting value elsewhere... } public static synchronized Sequence getInstance() { if(instance==null) // Lazy instantiation { instance = new Sequence(); } return instance; } public static synchronized int getNext() { return ++counter; } }   Some things to note about this implementation: Synchronized methods are used to ensure that the class is thread-safe. This class cannot be subclassed because the constructor is private

Hibernate Notes

  The Hibernate project has the structure as shown in the figure as above. We need one hibernate.cfg.xml file for hibernate configuration which handles connection pulling and other stuff like driver name, username of the database, password of the database, and the following properties.. Hibernate.cfg.xml <?xml version='1.0' encoding='utf-8'?> <!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD//EN" "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd"> <hibernate-configuration> <session-factory>   <property name="hibernate.connection.driver_class"> com.mysql.jdbc.Driver</property>   <property name="hibernate.connection.url"> jdbc:mysql://localhost/hibernatetutorial </property>   <property name="hibernate.connection.username"> root </property>   <property name="hibernate.connection.password"></pr