How can I return an int array in a JNI call? about jni-rs

[argv-minus-one]

Which errors do you get, and at which line of code?

[ShenFeng312]

Which errors do you get, and at which line of code?

75  | (env: JNIEnv, _class: JClass) -> jintArray {
    |                                  --------- expected `*mut _jobject` because of return type
...
109 |     array
    |     ^^^^^ expected `*mut _jobject`, found `JPrimitiveArray<'_, i32>`

I dont know how to fix it @argv-minus-one

[ShenFeng312]

I tried using the following code. It compiles successfully, but when I call it in Java, I encounter the following error: free(): invalid pointer. It seems like the reference to the array has become invalid. However, when I tested it in Rust, everything worked fine except for the last JNI-related call. What can I do to test it further?@argv-minus-one

#[allow(non_snake_case)]
#[no_mangle]
 pub unsafe extern "C" fn method_name<'a>
 (mut env: JNIEnv<'a>, _class: JClass<'a>)->JIntArray<'a> {
  .......
  let rust_slice: &[i32] = &vec;
    // println!("{}", 1);
    env.set_int_array_region(&result, 0,rust_slice);
    result 
}

[argv-minus-one]

Sorry! I seem to have missed that you replied here. Didn't mean to ignore you like that.

I need to see more of your code. The code you've listed so far looks sound, so you must have omitted whatever is causing the problem.

I will say that your extern fn should not be unsafe. Something in the function is causing undefined behavior, and because the function is marked unsafe, you aren't getting any compile errors about it.