Send message to C++/Qt application from outside?

Question

I have a C++/Qt application. I want to talk to it using Java. I know I can create TCP server/client. What other options do I have?

The problem is that I created TCP server inside the application and it does not work. But works fine when run in standalone mode. So looking for alternatives ways of communication between C++ and Java.

Answer 1

I have a C++/Qt application. I want to talk to it using Java. I know I can create TCP server/client. What other options do I have?

Basically, what you are looking for is IPC that is supported by both languages properly. You can find several solutions out there:

• Java and C++ socket communication.. Obviously, QtNetwork and the socket classes in there could be your friend for this on the Qt side.

• http://www.velocityreviews.com/forums/t279534-communication-between-a-c-and-java-program.html

• Java Native Interface. You would be able to call C/C++ methods from Java and vice versa, although this would be probably one of the slowest solutions.

• Shared Memory (SHM) (Here, QSharedMemory could aid you on the Qt side).

• Google Protocol Buffer

• Dbus (Here, QtDbus could aid you on the Qt side). This is not necessarily cross-platform a solution, however.

I would personally suggest to use raw socket based low-level solution with the Qt API. This is the most reliable in my opinion, and well-proven technology behind. There is Qt Jambi with Qt style API for the java side, and then of course in C++, you will get the QtNetwork API. This would at least provide you some consistency throughout the projects.