Comparing design patterns with enterprise patterns is not an easy task, because some behaviors are similar. Design patterns were the first subject that arrived, and this was covered in Design Patterns: Elements of Reusable Object-Oriented Software, written by Erich Gamma, Richard Helm, Ralph Johnson and John Vlissides. These design patterns were also the base to other patterns. Enterprise patterns became necessities that design patterns cannot resolve. This is because the design patterns describe solutions for of classes and objects relationships, but the enterprise environments have other necessities such as integrations between systems and software relations. However, enterprise patterns use some design patterns to solve problems.
The principal difference between design patterns and enterprise patterns is the aim; design patterns aim to organize and optimize the object-oriented design, and enterprise patterns focus on improving the use of Java EE tools as well as making communications between Java EE components better. Design patterns are focused on object-oriented and class and object relations, whereas enterprise patterns are focused on communication between Java EE components.
The use of design patterns makes it possible to reuse algorithms and also makes the design flexible; enterprise design patterns promote an abstraction of the complexity of Java EE tools and make it easier for the architecture to make changes.
Because of the complexity of architecture, the minimal use of enterprise patterns tends to be worse than the minimal use of design patterns. This is because, with the lack of use of enterprise patterns, the professional will always work with Java EE's complexity, increasing the probability of error.
Some implementations of Java EE patterns are already present in Java EE tools, and this makes them easy to use. In the next chapters, we will describe some of these patterns and their implementation using Java EE tools and see how these patterns will favor the design and architecture of your project.
