In this paper we present an approach to efficiently mix Java with asynchronous and synchronous concurrency and execute it on a specialized Java processor extended with capabilities for concurrency and reactivity. A new processor, which uses JOP (Java Optimized Processor) as its base, executes concurrent programs that comply with Globally Asynchronous Locally Synchronous (GALS) formal model of computation by clearly distinguishing between concurrency and reactivity control flow and Java control flow. The new processor, called JOP-Plus, can be used for embedded and even real-time applications in which majority of code is written in Java and the overall programs specified and structured in SystemJ system-level concurrent programming language.