Question

Can I pass a string from Java to my C++ routine using JNI function calls and modify its value in the C++ routine?

So far, I have seen examples of returning jstring, which I do not want to do. The other option that I know about is to get the ID of the string variable within C++ and set its value.

At present, I am playing with a function like the following:

JNIEXPORT void JNICALL Java_myexample_ChangeString
(JNIEnv *, jobject obj, jstring strJava) 

And I want to change strJava’s value. So, essentially what I am asking is if it Java can pass variables by reference and not just by value.

Thanks.

Answer 1

Java strings are immutable by design, you cannot change them, not even with JNI.