How to create new java objects in native methods?

Question

Hello,
Is it possible to create java objects and return the same to the java code from a native method?
Also is it possible to pass java objects other than String objects (for example, Vector objects) as parameters to native methods and is it possible to return such objects back to the java code?
If so how can I access those objects (say for example, accessing Vector elements) inside the native code?
What should I do in order to achieve them?
Regards,
Satish

Answer 1

bschauwe is correct in that constructing Java objects and calling methods on Java objects from native code is tough and takes some study. While you're at it, you might want to check out Jace, http://jace.reyelts.com/jace. It's a free open-source toolkit that really takes the nastiness out of doing this sort of stuff. For example,/**
* A C++ function that takes a java.util.Vector and plays around with it.
public void useVector( java::util::Vector& vector ) {
  // Print out all the contents of the vector
  for ( Iterator it = vector.iterator(); it.hasNext(); ) {
    cout << it.next();
  // Add some new elements to the vector
  vector.addElement( "Hello" );
  vector.addElement( "world" );
} All this code just results in calls to standard JNI functions like FindClass, NewObject, GetMethodID, NewStringUTF, CallObjectMethod, etc...
God bless,
-Toby Reyelts