GetByteArrayRegion in JNI

The question is: Suppose I use the function: (* env) -> GetByteArrayRegion (env开发者_如何学C, array, 0, len, (jbyte *)buf); In this case, a certain number of bytes written from the array to the buf or vice versa? Maybe a simple question, but I'm confused. Help, please:. In the documentation is not found.

`Get < PrimitiveTypeArray>ArrayRegion' is a family of functions that copies a region of a primitive array into a buffer. That's what the documentation says. It seems clear to me.