Using the default Xcode iOS App with SwiftUI, we can invoke Java code. The following steps are needed:

• Build GraalVM from source (GraalVM head works)
• Build OpenJDK Mobile static JDK libs (libjava.a, libnet.a etc)
• Combile all static JDK libs in one libjdk.a
• Annotate java code that needs to be exposed with @CEntryPoint
• Use Gluon Substrate and GraalVM native-image to compile Java code into an object file. This object file include most of the JVM.
• Compile required C code (sources in Gluon Substrate) that needs to work with GraalVM SubstrateVM.
• Combine the Java-based object file with the additionally required C code into another library, liboak.a
• Add libjdk.a and liboak.a to the XCode project
• Add graal_isolate headers to the XCode project
• From Swift code, create Isolate and invoke annotated @CEntryPoint code.