RoboVM is the bridge from Java to Objetive-C. Using this, it becomes easy to develop JavaFX 8 applications that are to be run on iOS-based devices, as the ultimate goal of the RoboVM project is to solve this problem without compromising on developer experience or app user experience.
On the contrary, iOS doesn't have a VM for Java, and it doesn't allow dynamic loading of native libraries.
Another approach is required. The RoboVM open source project tries to close the gap for Java developers by creating a bridge between Java and Objective-C using an ahead-of-time compiler that translates Java bytecode into native ARM or x86 machine code.