Compare and Contrast Design Patterns Essay Example

still making use of the original interface as well.

The adapter does the conversion between the two interfaces, and also converts the data that gets used in the forms needed within the overall solution. The adapter design pattern works like a bridge between to vastly different interfaces, making their interaction seamless and easy to control. Factory Design Pattern Another of the many design patterns used during development is the Factory Method design pattern. The factory method pattern is described as an object-oriented, creational design pattern that employs the concept of creating objects without exposing the exact instances of those objects’ code to the client.

Instead the client is referred to the new object created through a common interface. Surprisingly enough, this particular design pattern is one of the most widely used, yet not a lot of developers are familiar with it. Primarily, the reason for this is because it is not included in the patterns described by the celebrated Gang-of-Four’s design patterns book. The advantages of implementing the Factory method are: AdvantagesDisadvantages ? Easy implementation? Violates open/closed principle ? Only requires small changes to code? Uses sub-classing ? Encapsulation? Implies tight coupling between class nd products Facade Design Pattern The Facade pattern is very commonly used by developers in the software engineering field. The facade design pattern employs a simple interface to a larger body of code, such as a class library. This makes your architecture more flexible, and also less vulnerable. The disadvantage of using the Facade pattern is that in certain cases an adapter is used for a particular interface and polymorphic (adaptable) behavior must be supported. Observer Design Pattern Yet another design

commonly used design pattern is the Observer or subscription pattern.

This design pattern employs an object called a subject, creates a list of subject dependencies (observers), and alerts the observers of state changes or updates by calling a method. An advantage to using the Observer pattern is that its implementation handles distributed events. A disadvantage of using the Observer design pattern is that the overhead for its implementation is sometimes high due to using buffered resources. Proxy Design Pattern Finally, the Proxy design pattern is also a widely used and very functional design pattern.

A proxy, in software design, is a class operating as an interface to another resource or object. This object can be a file, a queue, a network connection, or some other resource that is difficult to copy or clone. Due to situations where several copies of intricate objects must be used, the proxy pattern can make use of more lightweight design patterns to lessen the overhead need to maintain them. The advantage of using the Proxy design pattern is that multiple proxy objects can be created, all of which contain a reference to the original, just like pointers.