Real-time systems are receiving increasing attention with the emerging application scenarios that are safety-critical, complex in functionality, high on timing-related performance requirements, and cost-sensitive. There is a trend, as observed in the industry, of the existing software without the real-time notion being re-developed to realise real-time features. Examples are autonomous vehicles, smart robots, 5G communication, etc. This paper utilises the principles of model-driven engineering (MDE) and proposes the first methodology that automatically converts standard time-sharing Java applications to real-time Java applications. It opens up a new research direction on development automation of real-time programming languages and inspires many open research questions that can be jointly investigated by the researchers from the embedded systems, programming languages as well as MDE communities.