You know Java, and now You want to use semantic technologies or build semantic web applications? No problem. Use the toolkit semweb4j and get in a single download all you need to semantic-web-enable your application. Very little semantic web knowledge is required.
Semweb4j consists of three pillars:
A universal wrapper API for different Java triple stores. Use Jena today and switch to Sesame tomorrow, without a line of source code changed (only a line in a property file).
Generate convenient Java classed from a RDF Schema.
Build a simple web application in minutes without ever seeing servlet source code.