Looking for a convenient way to call Java from C++

Question

It seems most documentation or helper libraries relating to JNI (Java Native Interface) are concerned with calling native code from Java. This seems to be the main use of it, ev

Answer 1

Yes, there are existing tools that do exactly this -- generate C++ wrappers for Java classes. This makes use of Java APIs in C++ more transparent and enjoyable, with lower cost and risk.

The one that I've used the most is JunC++ion. It's mature, powerful and stable. The primary author is very nice, and very responsive. Unfortunately, it's a commercial product, and pricey.

Jace is a free, open-source tool with a BSD license. It's been years since I last played with jace. Looks like there's still some active development. (I still remember the USENET post by the original author, over a decade ago, asking basically the same question you're asking.)

If you need to support callbacks from Java to C++, it's helpful to define C++ classes that implement Java interfaces. At least JunC++ion allows you to pass such C++ classes to Java methods that take callbacks. The last time I tried jace, it did not support this -- but that was seven years ago.