Java 6 was released in 2006 and Java 7 in 2011. No major changes were added to the Java7, many of the new features were present in Java 6 updates. After Java 7 Oracle has decided to implement a two years roadmap planning for Java, and the next major release will be available in 2013.
Java 8 has some interesting new features like lambda expressions, but the major new feature planned was Jigsaw, in fact Jigsaw was originally intended for Java 7 but was deferred to Java 8 and now it’s moved to Java 9.
In the previous article we dicovered some creational patterns used by JBoss, let’s discover now some structural design patterns used by it.
Structural design patterns are design patterns that ease the design by identifying a simple way to realize relationships between entities. There’s a common point between the majority of these kind of patterns, it’s the notion of interface or abstraction, so before discussing about structural patterns used by JBoss let’s discover the utility of using interfaces.
The majority of developers have already heard about design patterns, GOF(Gang Of Four) patterns are the most popularized, and each developer has his way to learn them , we can enumerate:
- Reading a book or a magazine.
- From web sites.
- From a collegue.
- Doing a training.
OSGi became very popular today, thanks to its modularity approach and its capability to enforce logical boundaries between modules. When we discover it the first time, the question is where to begin to understand how it works?
To understand OSGi concepts we will try to follow the puzzle approach, the idea is to begin with the trivial part of this technology, and search for other parts related to the found ones. And to assemble the puzzle we will be assisted by JArchitect that will be helpful to detect OSGi internal design.