Method invoke

rust/src/api/mod.rs:831–908

Invokes the method `method_name` of a created `Instance`, passing an array of `InvocationArg`s. It returns an `Instance` as the result of the invocation.

(
        &self,
        instance: &Instance,
        method_name: &str,
        inv_args: &[impl Borrow<InvocationArg>],
    )

    /// Invokes the method `method_name` of a created `Instance`, passing an array of `InvocationArg`s. It returns an `Instance` as the result of the invocation.
    pub fn invoke(
        &self,
        instance: &Instance,
        method_name: &str,
        inv_args: &[impl Borrow<InvocationArg>],
    ) -> errors::Result<Instance> {
        debug(&format!(
            "Invoking method {} of class {} using {} arguments",
            method_name,
            instance.class_name,
            inv_args.len()
        ));
        unsafe {
            // First argument: create a jstring to pass as argument for the method_name
            let method_name_jstring: jstring =
                jni_utils::global_jobject_from_str(method_name, self.jni_env)?;

            // Rest of the arguments: Create a new objectarray of class InvocationArg
            let size = inv_args.len() as i32;
            let array_ptr = {
                let j = (opt_to_res(cache::get_jni_new_object_array())?)(
                    self.jni_env,
                    size,
                    cache::get_invocation_arg_class()?,
                    ptr::null_mut(),
                );
                jni_utils::create_global_ref_from_local_ref(j, self.jni_env)?
            };
            let mut inv_arg_jobjects: Vec<jobject> = Vec::with_capacity(size as usize);

            // Rest of the arguments: populate the array
            for i in 0..size {
                // Create an InvocationArg Java Object
                let inv_arg_java = inv_args[i as usize]
                    .borrow()
                    .as_java_ptr_with_global_ref(self.jni_env)?;
                // Set it in the array
                (opt_to_res(cache::get_jni_set_object_array_element())?)(
                    self.jni_env,
                    array_ptr,
                    i,
                    inv_arg_java,
                );
                inv_arg_jobjects.push(inv_arg_java);
            }

            // Call the method of the instance
            let java_instance = (opt_to_res(cache::get_jni_call_object_method())?)(
                self.jni_env,
                instance.jinstance,
                cache::get_invoke_method()?,
                method_name_jstring,
                array_ptr,
            );

            // Check for exceptions before creating the globalref
            Self::do_return(self.jni_env, ())?;