jni_rs/mylib/src/lib.rs

143 lines
3.1 KiB
Rust

use jni::JNIEnv;
use jni::objects::{GlobalRef, JClass, JObject, JString};
use jni::sys::{jbyteArray, jint, jlong, jstring};
use std::{sync::mpsc, thread, time::Duration};
#[no_mangle]
pub extern "system" fn Java_me_ehlxr_HelloWorld_hello(
env: JNIEnv,
_class: JClass,
input: JString,
) -> jstring {
let input: String = env
.get_string(input)
.expect("Couldn't get java string!")
.into();
let output = env
.new_string(format!("Hello, {}! from Rust..", input))
.expect("Couldn't create java string!");
output.into_inner()
}
#[no_mangle]
pub extern "system" fn Java_me_ehlxr_HelloWorld_helloByte(
env: JNIEnv,
_class: JClass,
input: jbyteArray,
) -> jbyteArray {
let _input = env.convert_byte_array(input).unwrap();
let buf = [1; 2000];
let output = env.byte_array_from_slice(&buf).unwrap();
output
}
#[no_mangle]
pub extern "system" fn Java_me_ehlxr_HelloWorld_factAndCallMeBack(
env: JNIEnv,
_class: JClass,
n: jint,
callback: JObject,
) {
let i = n as i32;
let res: jint = (2..i + 1).product();
env.call_method(callback, "factCallback", "(I)V", &[res.into()])
.unwrap();
}
struct Counter {
count: i32,
callback: GlobalRef,
}
impl Counter {
pub fn new(callback: GlobalRef) -> Counter {
Counter {
count: 0,
callback: callback,
}
}
pub fn increment(&mut self, env: JNIEnv) {
self.count = self.count + 1;
env.call_method(
&self.callback,
"counterCallback",
"(I)V",
&[self.count.into()],
)
.unwrap();
}
}
#[no_mangle]
pub unsafe extern "system" fn Java_me_ehlxr_HelloWorld_counterNew(
env: JNIEnv,
_class: JClass,
callback: JObject,
) -> jlong {
let global_ref = env.new_global_ref(callback).unwrap();
let counter = Counter::new(global_ref);
Box::into_raw(Box::new(counter)) as jlong
}
#[no_mangle]
pub unsafe extern "system" fn Java_me_ehlxr_HelloWorld_counterIncrement(
env: JNIEnv,
_class: JClass,
counter_ptr: jlong,
) {
let counter = &mut *(counter_ptr as *mut Counter);
counter.increment(env);
}
#[no_mangle]
pub unsafe extern "system" fn Java_me_ehlxr_HelloWorld_counterDestroy(
_env: JNIEnv,
_class: JClass,
counter_ptr: jlong,
) {
let _boxed_counter = Box::from_raw(counter_ptr as *mut Counter);
}
#[no_mangle]
pub extern "system" fn Java_me_ehlxr_HelloWorld_asyncComputation(
env: JNIEnv,
_class: JClass,
callback: JObject,
) {
let jvm = env.get_java_vm().unwrap();
let callback = env.new_global_ref(callback).unwrap();
let (tx, rx) = mpsc::channel();
let _ = thread::spawn(move || {
tx.send(()).unwrap();
let env = jvm.attach_current_thread().unwrap();
for i in 0..11 {
let progress = (i * 10) as jint;
env.call_method(&callback, "asyncCallback", "(I)V", &[progress.into()])
.unwrap();
thread::sleep(Duration::from_millis(100));
}
});
rx.recv().unwrap();
}
#[cfg(test)]
mod tests {
#[test]
fn it_works() {}
}