JNI allows the use of function libraries made in languages such as C, C++, VB from Java applications. The advantage of JNI is that you don't need to write the calling function definition in Java. This ...

Java 25 integrates Compact Object Headers as a product feature through JEP 519, offering developers a potential 30% CPU reduction and significant memory savings without requiring any code changes. The ...

You can also produce the declaring code (Java has no header files) from the compiled class files. Those compiled class files can be distributed under any license you want (GPL Classpath exception).