There are various framework out there in order to make developer life is easy. "do not re-invent the wheel" concept is really applies here. however framework is like devil. if you used in correct way it will make you life easy. if not it will end your project forever.

Java is a programming language and computing platform first released by Sun Microsystems in 1995. There are lots of developers who use this language to develop there software. however some of them are writing code without knowing how it works and why do in that way. so lets discuss very small potion of java with "Why How and What"

SOA is architectural pattern in computer software design in which application components provide services to other components via a communications protocol, typically over a network. The principles of service-orientation are independent of any vendor, product or technology. (wiki)

WSO2 is an open source application development platform focused on providing SOA solutions for professional developers.