Design Patterns

A design patterns are well-proved solution for solving the specific problem/task. When should we use the design patterns? We must use the design patterns during the analysis and requirement phase of SDLC  (Software Development Life Cycle). Design patterns ease the analysis and requirement phase of SDLC by providing information based on prior hands-on experiences. Categorization of design patterns: Basically, design patterns are categorized into two parts: Core Java (or JSE) Design Patterns. J2EE Design Patterns. Core Java (OOPS) Design Patterns In core java, there are mainly three types of design patterns, which are further divided into  their sub-parts: 1.Creational Design Patterns Creational design patterns provide solutions to instantiate an object in the best possible  way for specific situations. Factory Pattern Abstract Factory Pattern Singleton Pattern Prototype Pattern Builder Pattern 2. Structural Design Patterns Structural design patterns are used to simplify and manage the relationships between objects and classes.  They help in creating compositions of objects to form larger structures while ensuring that  these structures are flexible and easy to manage. Adapter Pattern Bridge Pattern Composite Pattern Decorator Pattern Facade Pattern Flyweight Pattern Proxy Pattern 3. Behavioral Design Patterns Behavioral patterns provide a solution for better interaction between objects and how to provide loose-coupling and flexibility to extend easily. Chain Of Responsibility Pattern Command Pattern Interpreter Pattern Iterator Pattern Mediator Pattern Memento Pattern Observer Pattern State Pattern Strategy Pattern Template Pattern Visitor Pattern

    Java Design Pattern Interview questions