Passing pointers between C and Java through JNI

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I used the following approach:

in your JNI code, create a struct that would hold references to objects you need. When you first create this struct, return its pointer to java as a long. Then, from java you just call any method with this long as a parameter, and in C cast it to a pointer to your struct.

The structure will be in the heap, so it will not be cleared between different JNI calls.

EDIT: I don’t think you can use long ptr = (long)&address; since address is a static variable. Use it the way Gunslinger47 suggested, i.e. create new instance of class or a struct (using new or malloc) and pass its pointer.

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