Free Essay

Design Patterns

In: Computers and Technology

Submitted By computerblue
Words 926
Pages 4
Design Patterns
CSS/422
September 2, 2013

Design Patterns When developing enterprise software there are several design patterns to choose from. The factory method, abstract factory method, dispatcher data access object (DOA), and model-view-controller (MVC) are design patterns that play an important role in the software development process. By implementing proven design patterns the development process is accelerated and more efficient. The reuse of these patterns also prevents the occurrence of the more subtle issues that may cause significant problems while improving the code readability for architects and coders who are familiar with the design patterns. For effective software design, the consideration of issues that may not become apparent until the latter stages of implementation is essential (SourceMaking, 2012).
Factory Method The factory method design pattern creates a family of related objects instantiated by subclasses (University of Phoenix, 2010). This design pattern creates objects without detailing the class of object to be created. The factory method design pattern defines a separate method for the creation of objects by employing subclasses to override the derived type of object being created. In addition, the factory method makes a design more customizable while only slightly increasing its complexity. While other design patterns require new classes, the factory method simply necessitates a new operation (SourceMaking, 2012).
Abstract Factory Method
The design pattern known as the abstract factory method favors the factory method, but it adds a dimension to the factory method. The abstract factory method pattern creates a family of families, which is what adds the dimension (University of Phoenix, 2013). This design pattern uses a technique to encapsulate a group of individual factories that have a common theme. In this design pattern, the client doesn’t know which of the concrete objects from each of the internal factories it receives because only generic interfaces of the products are used. In abstract factory method the details of implementation from a set of objects is separated from the general usage of these objects.

Dispatcher The dispatcher software design pattern controls client access and re-directs or dispatches client requests to the proper party that can be located on the same or different tier (University of Phoenix, 2013). This design pattern eases the workflow implementation because the client requests are directed to the proper party. The Dispatcher design pattern separates system and business logic from view responsibilities, in addition to separating software development and Web production teams. Therefore, the Dispatcher pattern becomes accountable for navigation and view management. It is best utilized when outside resources select the view (Ball, 2013). Data Access Object (DAO) The data access object (DAO) software design pattern encapsulates access to data by hiding its complexity from users (University of Phoenix, 2013). This design pattern is an object providing an abstract interface to a database or persistence mechanism. The DAO contains a mapping from the application calls to its persistence layer, which isolates the public interface of the DAO. The Data Access Object (DAO) layer is an important component of high quality application architecture. Business applications generally require access to data from object or relational databases. The Java platform provides various methods for acquiring this data (CodeFutures, 2009).
Model-View-Controller (MVC)
The primary purpose of design patterns is to extract the high profile interactions between objects and reuse their behaviors in various applications. The model-view-controller design pattern separates presentation logic and business into three separate components defined by the other design patterns (University of Phoenix, 2013). Out of all the design patterns, the model-view-controller pattern is the only one that is an example of an architectural design pattern. This pattern isolates the domain logic and the user interface from one another. This permits the independent development, testing, and maintenance of each (IBM, 2011).

Design Patterns Comparison\Contrast All of the design patterns described above have one thing in common: each design pattern encapsulates or isolates certain data or objects from the user. The DAO and dispatcher patterns ease workflow. The factory method and abstract factory method are very similar except that the abstract method creates a family of families while the factory method which only creates families. The model-view-controller is the most contrasting design pattern because it is the only one that is an architectural design pattern. The DAO design pattern is the only pattern that purposely hides the complexity from the user. The other design patterns hide certain parts, but not necessarily the complexity.
In conclusion, design patterns are among the most powerful methods for building large software systems. Patterns provide well-known solutions to reoccurring problems that developers are facing. There are several benefits of using patterns if applied correctly. Although design patterns are only over decade old, the science of patterns is becoming established, allowing for consistent communication. By using well-known patterns reusable components can be built into frameworks. Today, providing frameworks for reusability is key to software development.

Reference
Ball, M. (2013). Dispatcher eases workflow implementation. Retrieved from http://www.javaworld.com/javaworld/jw-10-2001/jw-1019-dispatcher.html
CodeFutures. (2009). Data Access Object. Retrieved from http://www.codefutures.com/data-access-object
IBM. (2011). Model-View Controller Design Pattern. Retrieved from http://pic.dhe.ibm.com/infocenter/wchelp/v6r0m0/index.jsp?topic=%2Fcom.ibm.commer ce.developer.doc%2Fconcepts%2Fcsdmvcdespat.htm
SourceMaking. (2013). Design Patterns. Retrieved from http://sourcemaking.com/design_patterns.
SourceMaking. (2013) Factory Method. Retrieved from http://sourcemaking.com/design_patterns/factory_method
University of Phoenix. (2010). Design Patterns. Retrieved August 28, 2013, from University of Phoenix, CSS/422 Course Notes Web site.

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